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HomeMy WebLinkAboutPIP.Energy.Plan.Final.2008Pilot Point Community Energy Plan October 2008 I Pilot Point Community Energy Plan Revised October 2008 Pilot Point is located on the northern coast of the Alaska Peninsula, on the east shore of Ugashik Bay. Pilot Point is governed by a federally recognized tribe – The Pilot PointTribal Council and a second class city – The City of Pilot Point, as well as a consumer owned utility, Pilot Point Electric Utility which operates under the City. The population of the community consists of 86% Alaska Native or part Native. The community is primarily of Aluutiq ancestry, with members of Yup'ik and Inupiaq ancestry. During the 2000 U.S. Census, total housing units numbered 69. U.S. Census data for Year 2000 showed 48 residents as employed. The unemployment rate at that time was 7.69 percent, although 30.43 percent of all adults were not in the work force. The median household income was $41,250, per capita income was $12,627, and 20.83 percent of residents were living below the poverty level. Pilot Point is the charter member of the Sustainable Energy Commission of the Alaska Peninsula (SECAP). This organization was founded in 2001 to promote the development of economically and environmentally sustainable energy resources for the common good of the communities of Chignik, Port Heiden, Ugashik, Egegik and other communities in the Lake and Peninsula Borough. Table of Contents Page Executive Summary 1 Introduction 2 The Smart Village Energy System 12 Wind Diesel System Plan 28 Candidate Wind Turbines 40 1 Executive Summary III Pilot Point Community Energy Plan October 2008 II 2 Introduction V Recommended short term actions: 8 2.3 Long Term Actions: 8 3 The Smart Village Energy System 9 2 WIND-DIESEL SYSTEM PLAN 3.2 Electric Load: 24 3.3 Thermal Load: 27 3.4 Wind Resource: 29 3.5 Diesel Generators: 31 3.6 Wind Turbines: 33 Candidate Wind Turbines: 34 3.7 Installed Turbine Cost: 36 3.8 Number of wind turbines: 37 3.9 Fuel savings: 38 3.10 System configurations modelled: 39 3.11 Assumptions with respect to Wind Turbines and Associated Equipment: 49 3.12 ADVANCED DISTRIBUTED APPLICATIONS: 58 3.13 Training and Support: 59 3.14 Breakdown of Estimated Costs 61 4 Appendices 63 4.1 Wind Turbines 63 4.2 Turbine Maintenance: 68 4.3 HOMER Input Summary 69 AC Load: Electric Load 70 AC Wind Turbine: Vestas V15 - 65 kW: 70 AC Generator: JD 64 kW 72 AC Generator: Cat 160 kW 73 Fuel: Diesel 73 Fuel: Diesel2 73 Economics 74 Generator control 74 Emissions 74 Constraints 74 Pilot Point Community Energy Plan October 2008 III Executive Summary The Community of Pilot Point’s prosperity and way of life depend upon affordable energy. Minimizing dependency on diesel fuel, reducing the cost of operating energy infrastructure, and shifting away from the use of fossil fuels are keys to strengthening Pilot Point and the communities in the Bristol Bay Region. In 2005 the Alaskan Energy Authority completed a conceptual design for the upgrade of the diesel powerplant and bulk fuel storage system for Pilot Point. The Alaska Energy Authority anticipates construction funding in 2007 or 2008.In the meantime, the fuel prices have risen from $1.20 per gallon in 2000 to over $4.00 per gallon in 2007. High prices and the uncertainty of continued increases are impacting personal and community budgets as well as threatening the stability of the community. The Pilot Point Tribal Council and City of Pilot Point are committed to using their renewable energy resources to lower long term energy costs and strengthen the local economy. Moreover, efforts at wind development have been a catalyst for the formation of a regional sustainable energy collaborative between the tribes, cities, and utilities in the villages of Pilot Point, Chignik, Egegik, Port Heiden and Ugashik. This Collaborative, known as the Sustainable Energy Commission of the Alaska Peninsula or SECAP, has received financial support from the Bristol Bay Economic Development Corporation, Environmental Protection Agency, Administration for Native Americans, the Alaska Conservation Fund and the Alaska State Department of Community and Economic Development. The community of Pilot Point has undertaken this energy plan with the intention of transitioning from a manua lly operated diesel system to an advanced village wind-diesel energy system which is more reliable, more efficient, and more sustainable. If approached properly, the use of wind energy appears, increasingly more so, to be a technically and economically viable option. This plan is written to propose a reduction in diesel fuel in 3 ways: 1. Optimizing the efficiency of the diesel power plant through automated controls 2. Displacement of diesel fuel with wind energy 3. Management of the village energy system beyond the powerplant to the village as a whole. The concept of this plan is to provide a framework and a pathway for making decisions about how to build a sustainable community energy system. The framework helps with immediate decisions and consists of the wind diesel Pilot Point Community Energy Plan October 2008 IV plan, the recommendations to support a regional energy coordinator and organization, and the performance features of a diesel plant automation system. Due to markets, technologies and resource changes, this plan emphasizes the ongoing sustainability goal of creating a Smart Village Energy System. The SVES is an information and energy system, like the internet, that links the various energy components of the village together and provides the tools to manage them as one system. The concept of a Smart Village Energy System is presented here as a pathway to inform future decisions and provide long term direction. Continuing the development of an SVES will always keep the Pilot Point utility at the fore front of efficiency. The goal of a Smart Village Energy System is important because many of the solutions for keeping energy more affordable come down to controlling energy demand, especially at peak load times. Having the ability to interact with customers and control the load as well as the forms of generation, either through offering real-time incentives, like lower cost green energy from excess wind power or direct control of devices to shift electrical demand, will enable the utility to operate more efficiently, lowering costs and displacing more fossil fuels. The SVES is a versatile concept that can mean anything from temporarily shutting the commercial fishing ice maker to running multiple types of wind turbines or charging/discharging the batteries in a hybrid vehicle. The SVES is where the community must look next for viable opportunities. The framework components described in the plan are needed to create an efficient diesel and wind diesel system. Requirements of the functionality of the diesel plant controls, the proposed wind diesel architecture, wind turbine controllers, and a Boiler Grid Interface (BGI), are provided in order to understand the features that are needed in order to make the system work efficiently. These components will form the backbone of an expandable hybrid wind-diesel system and are included in the plan so that community leaders can make intelligent decisions when power upgrade funding becomes available. The control system described is generic in design and can operate various forms of equipment efficiently over a significant range of increases or decreases in community load. Recommended actions: Short Term 1. Coordination with regional organization and energy coordinator suppport  Develop agreement and involvement in a regional energy management organization to coordinate O & M activities and share expertise and costs of repairs. 2. Diesel power plant Pilot Point Community Energy Plan October 2008 V .  Upgrade diesel controls and generation voltage to reduce energy losses. 3. Wind project  Apply for permits for a wind project  Reinstitute wind resource assessment program, from the anemometer loan program to monitor the community energy load  Coordinate with AEA to extend the geotechnical investigations for powerplant and build fuel facility to the wind site.  Formalize land selection and site control for the wind project  Complete permitting for wind projects Long Term Actions 4. Develop a plan to create a village wide energy information Network  Complete an inventory of energy systems in the community, which can be included in the system.  Develop cooperative agreements with School District and clinic to monitor energy usage  Select sensors and communications methods  Develop sketches of how a local energy system and information system would be configured  Apply for funding to monitor fuel tank levels, to control inventory  Implement as soon as possible agreements with Indian Energy programs at the National Laboratories to participate in their Smart Grid programs  Create a web base information system outline  Continue a program to create the organization capacity, and develop relationships with all agencies. Introduction The truth is that there are no silver bullets for making a village energy system sustainable. Fuel costs are likely to continue going up. While the economy may turn up or down, people and businesses change and technologies continue to evolve. Small remote communities, like Pilot Point, are the most effected by these changes. Essentially, small, isolated, rural communities act as the “canary in the coalmine” as we are the first to be severely impacted whenever oil availability and prices fluctuate. The primary purpose of this plan is educational. Community leaders must understand the opportunities for energy system improvements and the energy saving potentials of their decisions. This energy plan is created around three key objectives: having good operating information, getting all the pieces of the Pilot Point Community Energy Plan October 2008 VI system work together efficiently, and being able to optimize the use of renewable and lower cost forms of energy. It is clear that the pathway to the use of wind energy and creation of a more efficient energy system is through the evolution of the current energy system, which includes the diesel generation plant, the electrical distribution system, and the community utility structure. This evolution includes the following objectives: 1. Automation of the diesel plant 2. Proper selection and sizing of diesel equipment 3. Power system generation and distribution improvements to lower losses and improve safety and reliability 4. Addition of control and power conditioning equipment to integrate wind with diesel 5. Installation of wind turbines 6. Expansion of the use of wind energy to provide “green energy” which will further reduce dependence on diesel fuel. 7. Expanded monitoring and control capabilities 8. Special metering 9. Decision support software These objectives are incorporated into three goals which are described in detail in this report. These are:  Power System Automation  Wind Diesel System Conceptual Design  The development of a Smart Village Energy System Fuel Consumption: According to the Powersystem upgrade Conceptual Design study conducted by the Alaska Energy Authority, annual diesel fuel consumption is estimated to be 104,000 gallons. This usage is split with approximately 40% going for electrical generation and 60% for heating and transportation. Planned projects could increase diesel fuel usage by another 10,000 gallons annually, with 8,000 gallons expected to go to heating fuel and another 2,000 to the production of electricity. In addition to the diesel fuel usage, another 26,000 gallons of gasoline is used for local transportation. While conservation and efficiency improvements will play a role in reducing consumption, 110,000 gallons of diesel fuel and 28,000 gallons of gas would be a reasonable annual estimate of the annual community fuel consumption. Fuel consumption estimates are described in the following tables, and based on Alaska Energy Authority reports. Table 1 Current Fuel Consumption and Storage Capacity Pilot Point Community Energy Plan October 2008 VII Product Average Annual Use (1) Peak Annual Use (2) Existing Gross Capacity (3) #2 Diesel Fuel 51,500 149,000 74,300 #1 Diesel Fuel 52,400 80,000 40,000 Unleaded Gasoline 26,100 31,300 25,500 Avgas (3) 11,800 20,000 10,000 Existing Total 141,800 280,300 156,800 (1) Based on City fuel purchases from 1997 through 2002. Peak and minimum years not included. (2) Peak use in 1999 due to airport and road construction projects. Future large construction projects can be accommodated with additional summer fuel deliveries. (3) Figures from AEA, Conceptual Design Report Utility Fuel Usage: According to AEA PCE reports the fuel usage by the utility to generate electricity ranged from 46, 339 gallons in 2000 to 37,383 gallons in 2005. During this time the conversion efficiency has averaged 11.6 kWhrs/gal. It is conceivable that with proper diesel genset selection and automation of the powerplant that diesel efficiency can be raised. An achievable short term goal would be 13 kWhrs/gal. A cost savings of 10 percent could be expected through diesel efficiency improvements. Table 2 Utility Fuel Costs Year Gallons Cost per Gallon Utility Cost 2000 46339 1.20 $ 55,606 2001 40030 1.28 $ 51,238 2002 36801 1.54 $ 56,673 2003 34841 1.57 $ 54,700 2004 35293 2.45 $ 86,467 2005 37383 3.68 $ 137,569 2006 26115 3.05 $79,555. 2007 Source of data, Annual PowerCost Equalization Reports, Alaska Energy Authority Future increases in consumption: The following near term projects are expected to increase future fuel consumption: Heating for New Homes – 2,000 Gallon #1 Diesel Use Heating Community Center – 2,000 Gallon #1 Diesel Use Heating Clinic & Trans. Housing - 3,000 #1 Diesel Use Water and Sewer Project - 1,000 Gallon #1 Diesel Use Increased Power Demand - 2,000 Gallon #2 Diesel Use Pilot Point Community Energy Plan October 2008 8 Growth associated increase in gasoline consumption – Allow 2,000 Gallon Increase in City Sales Increase in area tourism and guiding services – 4,000 Gallon increase in avgas Modernization recommendations: It may take many years and very significant resources to implement all the features of this energy plan. The modernization recommendations are intended to move Pilot Point forward as resources become available while, at the same time, permitting significant improvements in the energy systems capabilities. The following recommendations are grouped into two categories, short term and long term goals. Short term actions may begin as soon as Pilot Point decides to implement them. Note that many items specified as ‘short term” may take considerable time to complete however, Pilot Point may begin to implement short term actions immediately. The long term actions incorporate the creation of a Smart Village Energy System- its description is provided as guidance when decisions need to be made or where opportunities to move ahead present themselves. Recommended short term actions: Diesel powerplant Become involved in the diesel powerplant upgrade project- Request information about: project manager, project budget, schedule, system specifications, and pro forma grant agreement. Request that the project design include coordination of “As Built” drawings information with DCED MRAD for the powerplant and distribution system, bulk fuel system, district heating system, and wind farm. Upgrade diesel controls and generation voltage Become involved in the development of the budget project scope and specifications with the Alaska Energy Authority for the proposed new community power system and to arrange coordinate construction plans. Wind project Apply for permits for a wind project Apply for the anemometer loan program Reinstitute wind resource assessment program from the anemometer loan program to monitor the community energy load Coordinate with AEA to extend the geotechnical investigations for powerplant and build fuel facility to the wind site. Formalize land selection and site control for the wind project Complete permitting for wind projects Long Term Actions: Pilot Point Community Energy Plan October 2008 9 Develop a Village Wide Energy Information Network Complete an inventory of energy systems in the community, which can be included in the system Develop cooperative agreements with School District and clinic to monitor energy usage As built drawings of energy system and information system Apply for funding to monitor fuel tank levels, to control inventory Implement as soon as possible agreements with Indian Energy programs at the National Laboratories to participate in their Smart Grid programs Create a web base information system outline Continue a program to create the organization capacity, and develop relationships with all agencies. The Smart Village Energy System The thrust of this energy plan is to create a Smart Village Energy System (SVES). The SVES is a network, like the Internet, for energy and information that extends beyond the powerhouse, and links all generation sources, especially those outside the powerhouse to the customer loads, while supplying information which can be used to continually optimize energy system efficiency. The simplest way to conceive of the SVES, is that all the energy devices in a village share information and work together turning themselves on and off in an intelligent way. These advances are made possible through advances in digital technology, software, and communications. The concept of the Smart Village Energy System is included in this plan in order to provide an understanding that it is possible to build a smarter energy system by making use of many technologies (new and old) together in an intelligent way. With good choices over time Pilot Point can evolve a smart village energy system that generates distributed power and uses energy more efficiently and cost effective. This level of technology is necessary for achieving a more reliable, secure and sustainable energy system. The Smart Village Energy System encom passes five key technologies. They are: Advanced Controls: Diesel plant automation, Wind Distributed Energy Technologies- Wind, diesels, energy storage Sensors and Metering Devices- Intuitive user interfaces and decision support software – Integrated Communications, wireless or fiber optic Ethernet Each of these systems are described in greater detail later in this plan and the diagram below shows how communications link the other four technology areas together to create a Smart Village Energy System: Pilot Point Community Energy Plan October 2008 10 Automation of the diesel generators and wind turbines in the power system is made possible because of sensors and relays built into various devices. In the future practically every electrical component will have a controller with an address that can be located via the internet or by some other means. These sensors send information back to a supervisory control computer. This computer uses software to analyze operating data to control generator and load, and communicate the information to management in a usable form. When this computer is connected to the internet, a powerplant operator or utility manager can share this information anywhere with technicians, specialists, and customers. The Smart Village Energy System extends the automation and visualization capabilities of diesel power plant controller to the entire village energy system, and includes control loads as well as generation. This smart village energy system can include the electrical distribution system, any energy using device in the school, community building, residences and businesses. This system can be quite modest at first and start by monitoring energy usage by a single major user such as the school, but eventually the system will extend to individual appliances, such as residential water heaters or freezers. The design of the diesel plant supervisory control system is particularly important to the development of a SVES. The software used for powerplant control should not restrict software and hardware choices to a specific family of technologies. Over the last decade there has been an increasing trend toward the use of PC-based automation solutions. This trend is being driven by the advanced cross development with other PC and easy to use internet applications as well as increasing processing speed, functionality, and expandability. Careful consideration should be given to the selection of the power plant automation system. The Diesel Power Station Management Controller gives the smart village energy system its intelligent design. It is responsible for plant supervisory control, communications, and monitoring. In combination with the engine generators and electric feeders controllers, electrically operated breakers, and appropriate input/output and communications modules, the capabilities of the Station management controller and its software determine the capabilities of the power station control package. It is important that the supervisory controller software include capabilities to monitor and control systems beyond the diesel plant and to control community loads. The system must also be able to automatically perform other critical managed tasks such as starting and stopping pump motors, the integration of wind turbines, and the management of other forms of distributed generation or load. The supervisory station controller is responsible for continuously Pilot Point Community Energy Plan October 2008 11 and rapidly scanning system operating parameters and determining the optimum operating configurations. In addition the controller must be able to archive and display historical data for trending and high resolution diagnostics in order to detect and resolve operating problems. The concept of the Smart Village Energy System is presented in this energy plan in support of a core value of sustainability, having good management information, and good system control. It will involve selecting, installing, and maintaining sensors, creating web pages to display information and operating some new types of equipment. Assistance will be needed in the overall development of the system however, continued expansions are not beyond the capabilities of the community nor are the skills required to maintain it. The SVES is a high speed integrated communications and control interface between load, distribution, and generation similar to a computer network. Implementation of the Village Smart Grid energy and information system can take many directions. It can evolve through do-it-yourself grassroots efforts, which involve the power plant operator or others installing sensors, or purchasing equipment with embedded sensors that send information to the diesel plant. It could also entail a number of separate small initiatives, such as installing fuel tank level sensors and creating a spread sheet to track current and historical diesel fuel usage. Funding may also become available leading to a full blown software and hardware application monitored by an internet server and developed through agreements with a national energy laboratory, Sandia, which uses Pilot Point as a test site for monitoring and controlling the performance of different distributed energy technologies. Diesel Plant Automation: Until another technology evolves, diesel generation will be the primary source of energy for the community in the foreseeable future. The first step in reducing energy costs in the community is to always have the most efficient diesel generator set or combination of generator sets operating to meeting the electrical load. For this to be accomplished, consistent and reliably stable automated control over the diesel plant is needed. The design and capabilities of the diesel plant control system selects will affect long term operating costs of the utility and either expand or limit the ability of the community to perform sophisticated control routines and the way in which wind and other renewable sources of energy are used. Supervisory control: Supervisory diesel plant control is especially important as the methods of diesel station controls and grid stabilization largely determine the potential for displacing diesel fuel and thus economic viability of a wind diesel system. The capabilities of the diesel station supervisory control system largely determine whether the system can operate reliably over a range of penetration levels and with optimal fuel savings. With planning and coordination with the Alaska Energy Authority, the community can attain both objectives of reliable efficient diesel plant control and optimal system control performance. Pilot Point Community Energy Plan October 2008 12 Recent diesel plant control technology is based on the operation of a combination of discrete digital controllers that independently operate the various system components and report back to a system supervisory controller. Control system designs which use computerized generator set controllers, feeder breaker controllers, motor controller etc. have resulted in control systems which are less expensive, more reliable, and can provide a higher level of performance than older designs. This design also means that the supervisory controller or the station management system is responsible for fully integrating these components into a single system as well as provide the plant visualization, communication and decision support capabilities. The features of the system components are briefly discussed below. Station Management System (SMS): The station management system is a computer that operates the software which provides overall management and control of the diesel station. This controller should be capable of controlling diesel and other types of generators such as gas turbines and adaptable to the control of fuel cells, hydro turbine, and microturbines, as well as the distribution feeder breakers. Using sophisticated control algorithms, the SMS computer ensures that individual generators are correctly operated to achieve maximum efficiency. The station management controller accomplishes this by scanning a large number of process variables and automatically calculating new setpoints based on changing input values. The controller then alters the configurations of all the connected devices like diesel generators, feeders, and wind turbines for optimal operation. In a village wide energy and information system, the supervisory controller would also reach out into the community to manage energy loads such as pumps, motors, and compressors, controlling the community grid. A well designed SMS could initiate load control and special market based routines such as using excess wind energy for heat or enabling time of use, demand limiting, or other special metering programs. The supervisory controller capability must be able to be expanded to monitor fuel inventories, environmental and lighting control systems, battery systems, and fire and security systems. The supervisory controller collects all of the available digital and analog data and performs data logging, alarm recording, and report processing for the power station management. The supervisory controller must do much more than generator prioritization, feeder load shedding, and automatic black start procedures. The SMS controller must be able to communicate with a variety of field-bus communications protocols such as CAN, DeviceNet, and Modbus, to name a few. Finally, it will be important that the SMS can be connected to Ethernet to enable visualization of the power station and connection to the Internet. The following functions to be monitored include: Diesel generator manual/semi-automatic/automatic control for multiple, at least 4 generator sets. Feeder manual/semi-automatic/automatic control for at least 3 feeders. Wind turbine manual/automatic control Diesel configuration management for automatic diesel call up. Pilot Point Community Energy Plan October 2008 13 Automatic call up of replacement generator set before alarm shutdown. Automatic consumer feeder connection and disconnection (load shedding). Demand Managed Device control Station automatic black start. Parameter driven operation. Control of battery converter system (optional). Automatic alarm annunciation via voice, fax, and/or email. Operator message/email facility (to leave messages with operators). Automatic upload of data records and trends into central head office database. Station data recording and trending. Wind turbine data recording and trending. Consumer feeder data recording and trending. Fuel tank monitoring. Monitoring of station batteries and charger. Up and download facility of operator parameter sets. The supervisory controller for the powerplant must be expandable besides automatically performing all data logging, alarm recording, generator selection, feeder management, automatic starting, and many other procedures. Some supervisory control designs are more easily expandable than others. Adding sensors and controllers for other village energy systems, such as heat recovery, power distribution, and fuel metering may require the use of different communications protocols. PC bus based systems have more data storage and faster processing capability. PC based systems also have the advantage of plug and play configurations such as hot plug ability for replacement and the ability to add and subtract peripherals which communicate with various devices from different manufacturers. Understanding the features of the supervisory controller bus technology selected for the powerplant is important. Finally, the supervisory controller should be located in the plant switchgear or other central location for data collection, processing, and reporting to assist local and remote management, and operational decisions. Generator Supervisory Controller (GSC): Control systems for diesel generating plants have been traditionally based on analog control technology which has been developed over the last several decades. This technology requires discrete control equipment to monitor and control each variable of the plant operation. Modern control systems now mostly rely on digital control technology. There are several “gen-set controllers” (GSC) in the market place. Genset controllers offer a number of advantages over conventional powerplant systems, most notably a reduction in the number of components, reduced cost and increased reliability, and hierarchical control in which the gen-set controller reports to a station management controller. A single computerized GSC will perform synchronizing and load sharing functions as well as provide all protective functions (over voltage, phase imbalance, etc.) and continuously monitor all parameters of a single diesel engine and the generator. A well designed control system will allow the individual generators to be controlled, either manually by the operator, or Pilot Point Community Energy Plan October 2008 14 automatically through the Station Management Supervisory controller. The GSC’s ability to communicate with other components of the control system provides rapid update on the status of the system and also enables comprehensive diagnostics to be carried out. Since GSC’s are low voltage devices and are fabricated in a high volume electronics assembly facilities, these components are cost-effective and easy to replace if required. The other advantage of the generator controllers is that, with proper control switchgear design, these modules may be swapped between generators in the field, providing additional levels of redundancy to the power system. Features of the GSC’s include:  Engine Management- start/stop logic for the diesel engine  Measured Values- Voltage, current, frequency, power, power factor, temperatures pressures.  Counting functions- kWh, hours run, circuit breaker actions, number of starts, fuel consumption  Monitoring protection- Voltage, current, frequency, temperature, phase shift, active and reactive load, reverse power, underload, load unbalanced and overload.  Automatic Control- Frequency, voltage, load sharing, kVAr sharing, temperature  Synchronization- Using frequency and voltage adjustment  Remote Access- remote monitoring, control, parameter access via Supervisory Management System Controller One of the important advantages of an engine generator controller is that it is able to perform all the synchronization, speed control, and load sharing functions for the generator as well as the capability of processing analog values. The generator can also be manually controlled via an operator interface. The operator interface displays the values of setpoints - the status of genset and error messages in easy-to-read text. Feeder Monitoring System (FMS): Feeder controllers are micro-processor which operate multi-function protection relays. They provide the following functionality:  Feeder Input/output interface (5 digital alarm/status inputs, 3 relay outputs).  Feeder metering and power measurements (volts, amps, pf, kWh, frequency, kW, kVAr).  Modbus interface to the supervisory controller.  Local display for operator.  Programming of alarm texts via local display. Pilot Point Community Energy Plan October 2008 15 The feeder monitor provides the control interface to the feeder circuit breaker. The FMS monitors the status of the feeder and performs power measurement functions. Automatic and manual control of a feeder must be possible via the controller device and in conjunction with field-bus commands from the SMS. Wind Turbine Controller (WTC): A wind plant can consists of a number of wind turbines. Because the wind turbines are often of different manufacture and are some distance from the diesel plant a “Wind Turbine Controller” (WTC) is used. This WTC can be separate software built into the SMS controller or it can be an autonomous component which interfaces with the supervisory management system (SMS). The wind turbine controller consolidates the information and control from one or a number of wind turbine controllers with the supervisory controller (SMS). The SMS must contain software routines for operating the turbines in conjunctio n with the diesel power plant. This requires continuous communication with each WTC and continuous monitoring of the overall operation of each wind turbine. The SMS reports on the status of wind plant and receiving instructions for the supervision of the wind plant. The SMS controller should be able to accommodate both an autonomous WTC that has its own intelligence to monitor a number of subsystems and to safely start and stop one or many wind turbines as required. To be effective in a wind-diesel system the WTC must be utilized in a manner that optimizes system operation. Supervisory Control and Data Acquisition (SCADA): The Supervisory Control and Data Acquisition (SCADA) software largely determines the capabilities of the Man-Machine Interface (MMI) or operator interface. From a computer interface the operator uses the SCADA software giving the operator access all areas of the power system. The MMI is used to check system status, examine operational details, reset alarms, prepare reports and, if necessary, modify the operational characteristics of the system. From the interface, either locally or remotely, the capability of the SCADA system determines how easily the plant is to operate and manage. An effective SCADA system results in time and money savings. A key aspect of the supervisory control system is the ability to be operated remotely from multiple locations. This greatly increases the ability of the system operator and utility manager to monitor and to optimize the operation of the generating plant. A multiple user interface capability with high speed data recording and diagnostics enables a remote operator, technician, or engineer to share information and system operation via phone line, radio or internet with technicians and engineers anywhere in the world. This feature will reduce the number and cost of service calls, resulting in cost savings to the utility. The capability of the software which collects and displays energy system information must present the operator or manager with information that they can easily understand. Many control systems require separate custom software packages in order to visualize the operation of the power system. Visualization software runs on Pilot Point Community Energy Plan October 2008 16 an industrial panel PC, often a touch screen. This screen creates operator interface acting as a graphical user interface and should provide the following functionality:  Active control  Visualization of plant functions, components, load, outputs, etc.  Graphical data display  State reporting  High resolution diagnostics  Trending of historical data  Remote access  Alarm reporting Web Browser Based Visualization: It is very handy to have a web browser method of multiple user interfaces for visualizing the power system operation via the Internet. The Web Browser eliminates the need for special software and allows password protected access to operational data and control capabilities from any computer connected to the internet. Web based visualization further expands the usefulness of the control system by providing secure access without a dedicated communications software. Web based visualization is accomplished through a control software design which uses an open source software code, such as Java. Open source software will insure that the visualization programming can run on all major computer platforms and operating systems. Web browser visualization software enables the power system control panel to be displayed as an active web page which automatically communicates with the station management system to update the webpages with new information. This capability allows the operator, managers, technicians and engineers to share diagnostic and control information, even if they are unfamiliar with the system. Web browser based software does not require engineering time to modify. Modification of the display pages can be done by anyone who is familiar with the construction of web pages. Web based features can save a great deal of money by reducing travel to the site to diagnose problems and eliminating the need to hire an engineering firm to change displays. Powercorp provides a software program called Any View which uses the Mozilla Foxfire web browser as its base and can be run on virtually any computer. Any View uses Java (recently open sourced by Sun Microsystems) to allow communications between web browsers and the power control systems. Using this kind of an open source system allows the local operator, manager, or authorized representative to create display and control screens using freely available page layout mechanisms. The elements of this system - open source software, page layout tools, and controller access without detailed engineering form the basis of the community energy information system that will allow widely dispersed entities to share information readily. Pilot Point Community Energy Plan October 2008 17 Distributed Energy Technologies: Advanced energy generation and energy storage devices will play an active role in determining the village power system capabilities. Many advances have been made in wind generation including photovoltaic improvements, micro turbine manufacturing, improvements to battery and flywheel energy storage systems, power electronics for grid stability, and microelectronic developments that enable sophisticated control of almost every electrical appliance. Distributed generation and energy storage technologies will produce higher power densities, greater reliability, and improved real-time diagnostics. A short list of these devices includes:  Wind turbines  Diesel Generator sets  Photovoltaic panels  Battery storage systems,  Hybrid plug in vehicles  Thermal energy storage  Ice machines Integrated Communications: High-speed, fully integrated, two-way communication technologies, such as wireless or fibre-optic Ethernet can link continuous data measurements with the Smart Village Grid Energy and Information system central station computer or plant supervisory controller. An open architecture will create a plug-and-play environment that allows the grid components to talk, listen and interact. The various monitoring devices will use different communication methods with the central station management system. Most devices include the ability to communicate via Ethernet and connecting the components of the Village grid into an Ethernet interactive platform would provide real-time information and control power Wireless transmitter technology is evolving rapidly and offers significant advantages when used for measurement and monitoring applications. Wireless systems have been designed for applications with little to no access to power and hazardous or difficult to access locations where instrumentation changes are frequent and regular manual readings would be difficult. Wireless offers cost advantages in installation, cost, and mounting. Sandia National laboratories has a remote sensor group which can provide engineering design, software, and technical assist, and should be contacted about developing a cooperative agreement to work with the community in the deployment of these systems. Sensors and Metering Devices: Sensors and Metering technologies will enhance power system capabilities in many ways. Sensors detect the status of operating parameters on the system. Sensors and metering devices are measuring components that detect and communicate changes and the status of operating parameters in the system. In many cases they measure, accumulate, and report data. These devices are responsible for evaluating Pilot Point Community Energy Plan October 2008 18 the health of equipment and the integrity of the grid as well as supporting advanced control functions. More importantly, they eliminate measurement and metering tasks and prevent energy theft which improves utility revenues. Advanced automatic metering systems of customer electrical loads provide real time energy usage information and enable active consumer demand response and time based on green power pricing options. The budget and system specifications for the Pilot Point Powerhouse upgrade proposed by the Alaska Energy Authority should be examined to see if some of the capabilities described below could be incorporated into their utility system upgrade. These component improvements include: Smart Metering Systems: Smart metering is included in this energy plan, because measuring and collecting for energy sales keeps the utility alive. Knowing the role that a smart metering system can play in the utility will allow the community to think ahead and include smart metering in the budget process. Sm art metering systems are being employed to reduce meter reading costs, control electric usage, and to improve utility management. In general there are three types of smart or automatic electrical metering systems in use in rural Alaska today. The Turtle system, which is a powerline carrier activated system used by larger utilities like Kotzebue. The turtle system consists of a detector and a powerline carrier device that can be retro fitted on existing meters. The turtle system is generally expensive to im plement and although its feature set is increasing, the system is not designed for real-time response. The second type of system is the Elster wireless smart meter which is being used by the Alaska Village Electric Cooperative. The application of the Elster system is described in more detail below in order to provide an explanation of how such a system is configured and operated. The Elster Energy Axis system is based on a radio sub-network concept and offers many features which are attractive for village use. Some of these features are: cost, simplicity of installation, ease of system configuration, safety, remote connect/disconnect, load limiting, time of use rates, and data collection. The features which remote meter reading offers are expected to be very useful for small utility business management and include: remote connection, real time reading, load limiting and time of use rate setting. Other features in development are load management, energy conservation programs, and prepaid metering. The third type of system is the pre-paid metering system. Although not strictly an automatic reading system, both the Powerstats and Ampe prepaid metering systems are being used in a number of smaller communities. Prepaid metering offers many advantages to small communities and their customers.The primary advantage is that the utility is paid upfront for its electricity. There are several prepaid systems on the market. These will not be discussed here except to mention that prepayment features are planned for incorporating into the Elster wireless system and likely other automatic meter reading systems in the future. There are a number of prepaid Pilot Point Community Energy Plan October 2008 19 metering system s on the market. Landis and Gyr offer a system costing in the range of $200 per meter. Pilot Point is equipped with the Powerstat Prepaid Metering System for all its residential customers. The use of some prepaid meters would necessitate the installation of a separate and redundant system to execute demand side management methods such as the sale of excess green energy for heat. The advantages of automatically remotely controlled energy meters is that various demand managed schemes can be activated, meters easily read, and energy use information can be consolidated. In the long run automatic meter reading systems will play an increasingly important role in community energy management and customer choice. The Elster Wireless Metering System: The Elster system consists of single phase sender and three-phase collector meters which can be installed in the powerhouse or another location. Data is transmitted wirelessly, to the collector meters and deposited into the site based computer, or the Pilot Point Community Energy Plan October 2008 20 plant supervisory controller. Data would be accessible via a Local Area or Wide area network or telephone connection to a computer in the powerhouse with the installation of a modem or internet connection to allow remote communication with the three-phase collector meter(s). This communication will enable data download to a computer server and implementation of meter management routines. The system is very flexible with programming of the meter to run various routines and rate determinations. If a WAN is not operating, connections can be made of existing telephone lines at the school that will be used to communicate with the collector meter installed at that location and of the base station computer at the powerplant. There are various local computers to dial both of the A3 meters, and physically download the data to an onsite computer and then email this data to the AEA. Proposed locations for the collector sites are the school and the powerhouse. The ideal collector site(s) would have: Access to a dedicated phone line or Lan connection Maintenance access Sufficient distance and obstacles between Rex meters to demonstrate capability The Elster Electricity Energy Axis System uses a network of single phase electronic REX meters and A3 Alpha meter/collectors equipped with two-way 900 MHz radio transceivers. The REX or single phase meters communicate with the A3 Alpha collector meters that manage the radio frequency network and return meter readings via telephone or wide area network (WAN) to a central computer where the readings are captured for analysis. One or two A3 Alpha collector meters should be sufficient for use in Pilot Point as well as the remaining REX meters. In addition to the meters there are a couple of software kits ( Energy Axis Starter Kit) for obtaining remote meter readings. Beside the meters and the access kit, the system consists of software for configuring the Energy Axis Meters. The system comes with two management software options. Both systems use a computer to poll the meters for data and depositing the data on the on-site PC. The software then marries the records and stores them in an individual file for each meter. Data from the meters is read and consolidated into analytical reports. The Elster system is mentioned in this report because it can provide the full range of features from prepayment to automatic reading, management reporting, and execution of demand managed and time of use operating schemes. The system can also be utilized for bi-directional energy accounting for those customers who choose to self generate. Village Energy Information and Control: Buildings are being built and upgraded with energy conservation in mind. These building include building automation systems which monitor and control lighting, heating and ventilating and security systems to optimize performance. The core technology that makes this level of control possible are digital contactors and relays that are microprocessor controlled and are addressable, typically using Ethernet communications. The Smart Village Energy System is about collecting and using the Pilot Point Community Energy Plan October 2008 21 information and the ability to control these appli ances. The community should think broadly about the information and control that is important. At this time it may not be important or cost effective to control the lighting in the school or community building, but it may be important to know the inventory of fuel in the bulk fuel tanks and how rapidly that fuel is being used. This can lead to predictions of when the next shipments will be needed and how much fuel should be purchased. Monitoring of the powerplant, fuel, and heat recovery systems as well as environmental conditions are done through sensors which measure pressure, temperature, humidity, level, voltage, current, wind speed, direction, count pulses and light intensity. Decision Support Software: To be effective operators and managers must have the tools to understand, track and manage energy usage. The capabilities of the system software make all a manager to understand how all the pieces of the system are working. The most obvious way of conserving fuel is to always run the most efficient diesel genset to meet the load. In order to accomplish this, the operator needs to be able to visualize the characteristics of the load in a graphical load profile that can be resolved on a subsecond basis. A smart village energy system will require wide, seamless, real- time use of applications and tools that enable plant operators and managers to make decisions quickly. The software that goes along with the SVES could be expected to visualize the load, diagnose problems, read meters, and automatically produce regular and custom management reports to:  Monitor engine generator performance (fuel use, hours of operation, outages)  Account for energy resources, uses and costs (wind and diesel).  Keep track of fuel usage to competitively procure fuel.  Provide information to effectively work with customers and public agencies  Provide for the benchmarking of energy usage  Procure training for plant operators  Execute energy management schemes Demand Managed Devices: Refrigeration demand managed devices are any electrical load which is interruptible for any period of time and can be used to control the load demand at the powerplant. A common demand manage device in fishing communities is a blast freezer. To control a blast freezer a Demand Managed Device Controller would be installed in the freezer’s electrical panel. A communications link to the power station, typically via a wireless or fiber optic connection is made to the device. The demand device functions in two ways. If the freezer is to be turned on the dem and device controller sends a signal to the powerhouse to establish sufficient generation capacity to start and run the generator. This feature insures that large amounts of excess generation capacity are not kept on line in the event the freezer might be operated during high levels of spinning reserve, waste fuel. The other operating mode is similar, except that the power station supervisory controller can interrupt operation of the freezer through the Demand Managed Device Controller for prescribed periods of time. Pilot Point Community Energy Plan October 2008 22 The DMDC monitors the thermostat in the freezer to maintain the temperatures in the freezer. Essentially, any electrical device can have a DMD controller installed and operates in two modes automatically, “okay to run,” and “request to run.” If sufficient capacity is available for the device asserting the “Request to run” signal, it will be started immediately. Other devices will not be allowed to start for the following 10 seconds (time delay is a parameter, but mostly based on communication round-trip times with the Power Station Master Controller) allowing the Demand Managed Device Controller to ascertain whether enough spinning reserve still exists on the power system. At the end of the running period of the Demand Managed Device, the Demand Managed Device Controller will hold a request for spinning reserve for a period of 10 minutes (time delay is parameters influenced but mostly based on the cycle time of the demand managed device) before returning the spinning reserve request to zero and allowing the power station to return to standard levels of spinning reserve. If a communications failure occurs, the Demand Managed Device Controller will not allow any further Demand Managed Devices to start. Units that are running will be allowed to keep running until they stop. To start and run demand managed devices, the Demand Managed Device Controller must be switched to manual mode. Ethernet over Fiber or Wireless Communications: The Ethernet is a family of computer networking technologies that are used to create local area networks. The Smart Village Energy System would take advantage of Ethernet wiring and signaling standards that are built into many modern electrical devices to provide control and monitoring access to each device and connect them together into a network. Ethernet protocols provide a common address and communications network to link the diverse components of the system together into a local area network. The Ethernet standards allow the combination of twisted pair wiring and fiber optic backbones which carry huge amounts of data and wireless technologies that can be quickly deployed to communicate with each other. This provides a broad level of flexibility in configuring a Smart Village Energy System. Pilot Point Community Energy Plan October 2008 23 Wind/Diesel System Plan Pilot Point Tribal Council initiated a wind speed monitoring program in March 2001 with the support of the Alaska DCED Mini-Grant. Wind data was collected monthly by Pilot Point personnel and electric load data was collected in 2003 as part of the AEA Rural Power Systems Upgrade Conceptual Design Study for a new power system for Pilot Point. In addition the community installed a 10 kW Bergey wind turbine with intentions to install a second to demonstrate the effectiveness of wind energy. The available data is analyzed in this section and the economic and financial feasibility of a wind diesel is analyzed. Wind-diesel is the generic term given to energy systems that combine diesel powered electrical generators with wind turbines and specifically designed to reduce the load on the diesels and displace diesel fuel. Wind-diesel systems can be characterized as low, medium , or high penetration. Low penetration systems enable small amounts of wind power to be used in parallel with diesel systems at levels where the diesel operation is virtually unaffected. The installation of a Bergey 10 kW wind turbine on the Pilot Point grid can be characterized as a low-penetration system. Medium penetration systems also operate in parallel with the diesel system but contro l modifications are required to ensure the diesel plant is not subjected to unacceptable load conditions in which the wind turbine energy over powers the ability of the diesel generators to maintain stable frequency and voltage levels. At high penetration levels, the wind plant is sufficiently large that it can, during high winds, meet the entire load requirements of the community. During these times special design measures can be implemented which allow the diesel plant to be turned off while the system is operated on autonomous wind power. High penetration systems require very sophisticated control systems to dispatch the different generation components reliably and to maintain the system stability during periods of wind only operation. For example, in a plant with a diesel capacity of 200 kW, low, medium , and high penetration wind-diesel systems might have 50 kW, 150 kW, and 350 kW of wind generating capacity installed respectively. The installation of low penetration systems have virtually no impact on the diesel plant operation. Wind energy injected into the grid marginally reduces the fuel required from the diesel plant but fuel savings are limited due to the small size of the wind plant. Higher penetration levels impact the operation of the diesel plant. In circumstances when the wind power provided to the grid forces the diesel into low or negative power operation, the control system must take steps to protect the d iesel. In medium penetration, the supervisory controller and engine generator controllers provide set points for the diesel generator sets and an external load is provided to keep diesel operating at a prescribed minimum level. In high penetration systems the diesels may be shut down during periods of high winds. During autonomous wind op eration the wind-diesel controller regulates voltage and frequency through special system components which are usually controlled by the diesel. Higher penetration systems are more complex and they are more expensive to build and operate. Higher Pilot Point Community Energy Plan October 2008 24 penetration systems usually entail the installation of large excesses of wind capacity making the economics challenging. The purpose of all wind diesel designs is to maximize fuel savings with the most economical system. The plan proposed for Pilot Point is to construct a scalable medium penetration system which minimizes diesel usage and can in the future be converted to a diesels off system. The proposed system allowed to operate at low load set points while stabilizing the grid using a fast acting power electronics boiler grid interface to capture the excess wind energy. The economic viability of using wind power depends on the available wind resource, the cost and efficiency of the conversion technology, and market for the energy. The following section of this report provides a preliminary analysis of wind diesel feasibility based on available data and proposed options for retrofitting the existing diesel power system in Pilot Point, Alaska to a wind-diesel system. Two software programs were used to conduct this preliminary analysis. These are Windographer (www.mistaya.ca/windographer) which was to analyze the wind data and HOMER (www.nrel.gov/homer) to model the wind-diesel systems options. These programs combine information on the wind resource, the load, cost data and construction, and operating assumption in order to compare the economic performance of various wind diesel configurations. Electric Load: The highest value energy in the community is the electric load and thus the target for fuel displacement. The graph below shows the measured real electric load at Pilot Point from November 2004 to April 2005: Figure 1, Electric Load Profile Pilot Point Community Energy Plan October 2008 25 From this measured data a 24-hour average load profile was calculated for each month. This average was used filled in the missing May through October data by assuming that the April profile would apply to May, June, and July, and the November profile would to August, September, and November. The data was then scaled to daily profiles which were used to create the seasonal profile shown below. Figure 2 Average Monthly Load. Monthly Average Electric Load 0 10 20 30 40 50 60 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecAverage Load (kW)Measured Estimated The resulting electric load data appear in the graphs below: Pilot Point Community Energy Plan October 2008 26 Unfortunately, an entire years worth of load data was not available. Therefore, it is anticipated that the summer energy usage peaks due to fishing and construction activities may be obscured. This would include any off site gensets that may represent a potential load increase. The available information implies a system designed to meet an average electrical load of around 50 kW, a peak load of less than 80 kW and minimum load of 20 kW. This data provides a baseline for comparing various the wind diesel designs. The unknowns in the data as well as potential to attract additional summer load, highlight the importance of a scalable control backbone which is able to accommodate different Pilot Point Community Energy Plan October 2008 27 sized diesel generator sets, different sizes and types of wind turbines and different control and penetration levels based on available wind energy and load requirements. Thermal Load: In most wind diesel system designs, a common method of balancing fluctuations in the wind is to use thermal loads or heat loads. When there is excess wind, a thermal load, a hot water boiler, or a furnace using ceramic bricks is quickly turned on. When there is a lull in the wind, the thermal or heating load is quickly turned off. A certain level of interruptible thermal load acts as a buffer to stabilize changes in load or wind turbine output. This thermal energy has value. In order to examine the potential for displacing thermal energy with wind, the AEA thermal load calculator was used to generate thermal load data. The inputs are shown below. The assumed total amount of displaceable heating fuel was estimated to be 46,000 gal/yr. It was further assumed that this usage was split as 36,000 gal/yr for space heating and 10,000 gal/yr for domestic hot water. A boiler conversion efficiency of 80% was also assumed. Weather data from the National Climatic Data Center was not available for Pilot Point, but was available for Port Heiden, the closest reporting station. This data included monthly average temperatures. This data indicates that thermal energy usages ranges from a high of 250 kW to a low of 80 kW. More data collection and analysis would be required to confirm this estimate, however the results appear reasonable. The greatest need for heat is in the winter, which appears to correlate with the availability of wind energy. Figure 3 Load Spreadsheet Calculator Pilot Point Community Energy Plan October 2008 28 The resulting thermal load data appear in the graphs below. Figure 4 Thermal Load Display Pilot Point Community Energy Plan October 2008 29 Wind Resource: Myles O’Kelly provided a wind data set collected at Pilot Point between Sept ember 2003 and March 2006. This data set contains data from two anemometers at heights of 69 feet and 89 feet above ground. The data set contains many gaps, but it covers every month of the year and was sufficient to synthesize a year of data for use in HOMER. The time series graph and summary graphs appear below: Figure 5-Wind Resource Time Series Graph Pilot Point Community Energy Plan October 2008 30 The summary graphs of the wind resource appear below. Pilot Point Community Energy Plan October 2008 31 The available data set indicates an average wind speed of 12.1 mph at 69 feet above ground, and 12.9 mph at 89 feet above ground. From that data set, Windographer calculates that the average wind speed at 58 feet is 11.6 mph. This is much lower than the average wind speed at 58 feet of 15.3 mph reported for “the best site in Pilot Poin t” in the “Pilot Point Wind Speed Monitoring Project Summary Report”. Myles O’Kelly mentioned in an email that his data set was affected by tower shading, which might account for some of the discrepancy. Based on this information the data set was compared to Port Heiden data and reevaluated. While this data set will require further confirmation, an annual average of wind speed at 13.4 mph at 58 feet, was used for this analysis. At 80 feet, the assumed hub height of the wind turbines, this translates to an average wind speed of 14.6 mph or 6.55 m/s. Windographer was then used to synthesize a one-year hourly data set of wind speed at 80 feet above ground from the data set that provided by Myles O’Kelly. This data was then scaled to an average wind speed of 6.55 m/s. A sensitivity analysis of -10% to +10% of the wind speed was used to estimate annual energy output from candidate wind turbines. It is recommended that the wind monitoring data be supplemented with a dedicated monitoring device to confirm th ese results. Diesel Generators: Since funding for upgrades planned for the Pilot Point by the Alaska Energy Authority are uncertain, this feasibility of wind takes into consideration both the diesel in the existing power plant and those proposed to be used in the new diesel power plant. The assumptions appear in the tables below: Table 3 –Assumptions for existing power plant Generator Capital Cost ($) Replacem ent Cost ($) O&M Cost ($/hr) Lifetim e (hrs) Min. Load Ratio Fuel Curve Intercept (L/kWh) Fuel Curve Slope (L/kWh) Cat 90 kW 0 55,000 4.90 80,00 0 30.0 % 0.0800 0.250 Cat 113 kW 0 70,000 5.60 80,00 0 30.0 % 0.0800 0.250 Cat 160 kW 0 99,000 6.90 80,00 0 30.0 % 0.0800 0.250 Table 4 – Assumptions for new diesel power plant Generator Capital Cost ($) Replacem ent Cost O&M Cost ($/hr) Lifetim e Min. Load Ratio Fuel Curve Intercept Fuel Curve Slope Pilot Point Community Energy Plan October 2008 32 ($) (hrs) (L/kWh) (L/kWh) Existing 64 kW 0 38,000 4.10 80,00 0 30.0 % 0.0373 0.264 New 64 kW 38,000 38,000 4.10 80,00 0 30.0 % 0.0373 0.264 New 95 kW 58,000 58,000 5.00 80,00 0 30.0 % 0.0298 0.211 Fuel curve parameters for each generator were estimated using data for the closest sized diesels generators listed on www.cat.com. (The information for the John Deere generators was not available for this report.) Capital and operating costs for each generator were estimated using the Alaska Energy Authority’s cost data, plotted below: Figures 7 and 8- Diesel Costs Diesel Installed Capital Cost y = -0.178x2 + 673.72x - 4334.8 $ $ 100,000 $ 200,000 $ 300,000 $ 400,000 $ 500,000 $ 600,000 0 100 200 300 400 500 600 700 800 900 1000 Rated Capacity (kW)Installed Capital Cost Pilot Point Community Energy Plan October 2008 33 Diesel O&M Plus Overhaul Cost y = -2E-05x2 + 0.0324x + 2.1168 $0/hr $2/hr $4/hr $6/hr $8/hr $10/hr $12/hr $14/hr $16/hr $18/hr 0 100 200 300 400 500 600 700 800 900 1000 Rated Capacity (kW)O&M Plus Overhaul Cost Wind Turbines: For the purposes of feasibility, three different turbines were modeled. These include the Bergey Xcel-S and two variations of the Vestas V15, the one rated 35 kW and the one rated at 65 kW. These turbines were selected for costs and suitability for the application. The graph below shows a comparison between the two power curves. The table below shows the assumptions used for both Vestas turbines. Pilot Point Community Energy Plan October 2008 34 Table 5 – Wind Turbine Assumptions Turbine Model Rated Power (kW) Hub Height (m) Lifetime (yr) Installed Capital Cost ($) O&M Cost ($/yr) Vestas 15 – 35 kW 35 24.4 15 200,000 4,800 Vestas 15 – 65 kW 65 24.4 15 200,000 4,800 Candidate Wind Turbines: Over the last 20 years, successful wind turbine designs increased confidence in the viability of wind power. This confidence drove governments, especially in Europe to provide subsidies and other incentives for wind energy development. As demand for wind systems rose, manufacturers responded shifting their resources away from small and medium sized machines (50 kW to 500 kW) toward the production of larger machines ( 1 to 5 MW). Today the major manufacturers such as Vestas, Bonus, Gamesa, and GE only make standard production wind turbines in the megawatt and multi-megawatt size ranges. This size turbine is too large for a wind diesel syst em in Pilot Point. The community lacks the civil infrastructure to construct and maintain a large machine, and it lacks the ability to integrate 1 MW or more of electrical output into the energy system. A complete evaluation of the market place for small and mid-sized turbines was not conducted for this plan. However efforts were made to identify the number of manufacturers producing turbines with rated generator capacities ranging from 35 to 300 kW’s, and rotor diameters of 12 to 30 meters, that would be suitable for use in Pilot Point. The number of choices in this size range is limited. Due to the remoteness of the site, no large (200 + ton) cranes or other facilities required to handle the delivery and installation of large wind turbine are ex pected to be available. Only three turbines were analyzed for this plan. The Bergey 10kW, and the remanufactured Vestas V -15, 35 and 65, both on tilt up towers were considered for cost and constructability reasons. The HOMER analysis can be easily updated or expanded to include other turbines. The candidate wind turbines were identified as: Pilot Point Community Energy Plan October 2008 35 The Bergey 10kW , is a very popular direct drive wind turbine that has been sold all over the world. This machine is simple in design and comparatively easy to install. However the energy output from the turbine is limited. This is a concern because the small output jeopardizes its financial viability. Entegrity (AOC15/50), fourteen (14) of these machines have been installed in Kotzebue, 4 machines have been installed in Selawik, and 2 machines are installed in Wales. This machine has experienced repeated problems with the tip brakes and requires frequent maintenance. Northwind 100kW, one (1) machine is installed in Kotzebue, and the Alaska Village Electric Cooperati ve has installed six (6) of these machines, three (3) in Kasigluk and three (3) in Tooksook Bay. This appears to be a very good machine, however, it must be installed on a tubular tower, which requires a crane. The machine and tower delivered Seattle cost approximately $ 350,000. After shipping and installation this machine is estimated to cos t in the range of $ 600,000 to $ 750,000 in a remote location. A 100kW wind turbine will produce different amounts of electricity based on the average wind sp eed at your site. The Northwind 100 utilizes advanced turbine technology to ensure excellent energy capture for its size. For example, if your site has an average wind resource measuring 4 meters per second (8.90 mph) and follows a standard distribution (i .e. a “bell curve” of wind speeds), you can expect the Northwind 100 turbine to produce approximately 70,000 kilowatts- hours of energy in a year. If your average wind speed is 6 meters per second (13.4 mph), the Northwind 100 will produce approximately 214,000 kilowatt-hours per year. Pilot Point Community Energy Plan October 2008 36 Fuhrlander 30KW and 100kW machines and several types of remanufactured machines. According to the Fuhrlander representative for the U.S. these machines have been discontinued by the manufacturer, or they may be ordered but the manufacturing lead times are well in excess of one year. Vestas, V-15 (35kW, 65 kW), V-17 (90 kW), V-27 (225 kW) (Remanufactured) There is a growing demand for proven reliable remanufactured mid sized machines. Turbines are being installed in St. Paul, Kotzebue, and Nikolski. Larger V- 47’s are being proposed for installation in Sand Point, and one V-27 is being proposed for Tin City. These machines were selected for their cost effectiveness, availability and proven design. * Short descriptions of these turbines are discussed in the Appendix: Installed Turbine Cost: The total (turn-key) installed cost of a wind turbine is made up of the following, Wind turbine generator and spare parts (includes tower, and controller, SCADA is optional.) Installation Costs—labor, materials, site preparation, foundation, erection, permitting, inspections and hook up. Transmission, distribution, and power conditioning equipment. Includes circuit breakers, power conditioning, power lines, and transformers. Site costs Shipping and Transportation costs Miscellaneous costs, permitting, engineering fees, etc. Warranty and service agreements Table 6 – Wind Turbine Cost Assumptions Turbine Model Tower Type Rated Power (kW) Hub Height (m) Lifetime (yr) Installed Capital Cost ($) O&M Cost ($/yr) Vestas 15 – 65 kW Tilt up lattice 65 24.4 15 200,000 4,800 Vestas V- 15 35 kW Tilt up lattice 35 24.4 15 200,000 4,800 Vestas V17 Tilt up lattice 90 24.4 15 250,000 4,800 Pilot Point Community Energy Plan October 2008 37 Vestas V27 Tubular 225 30 15 525,000 6,400 Northwind 100 Tubular 100 25 15 650,000 4,800 Fuhrlander 100 Tubular 100 35 15 700,000 4,800 Fuhrlander 250 Tubular 250 42 15 880,000 6,400 General costs were provided for each wind turbine installation, as a starting point for the analysis. These cost estimates are based on previous construction knowledge and information provided by the turbine suppliers. Maintenance estimates are provided for the turbines, based on a technician visiting the site twice a year. These costs can be reduced by training local labor. Number of wind turbines: The amount of installed wind capacity depends on the wind resource, the number and operating characteristics of the wind turbines, and uses for the energy. Standalone system designs tend to favor multiple turbine installations. The proposed design includes three. With multiple turbines, the importance of flexible control system design cannot be over stressed. The control system is needed to support a mix of various equipment types, configurations and operational strategies, and makes it possible to easily add or change wind capacity in the future. Adding future wind capacity at the time of initial construction should be considered to reduce equipment, labor, and other mobilization costs. The wind data is not sufficient to describe how the wind power output from a particular wind turbine changes with natural changes in wind speed. Gusty winds cause short term variations in wind energy. One of the main advantages to having multiple wind turbines in a wind plant is that the wind turbines operate independently of each other and their outputs do not rise and fall with the wind at the same time. This factor is especially important to stand alone wind-diesel systems because large fluctuations in power output must be considered in the design. When a wind gust sweeps through a site, it reaches som e turbines sooner than others. While part of the wind plant may experience decreasing power output, another may just begin an upswing in power production. As a result, the total wind plant, with multiple turbines, sees fewer relative power variations than a single wind turbine. In general, the output power smoothing effect is more prominent with an increasing number of turbines and a greater distance between turbines. The operational characteristics of the wind turbines themselves affect the design. The Northwind 100 wind turbine does not require a current or a powerfactor feedback to achieve regulating behavior. Current reduction and frequency control are important advantages to using the Northwind turbine. The turbine is of fixed pitch design and therefore the power output of the turbine cannot be regulated, and so energy recovery loads must be added to the system. Future plans for Pilot Point Community Energy Plan October 2008 38 this turbine are to develop the ability to establish power output setpoints through the electronic inverter. The Northwind is electronically more complex than traditional wind turbine designs. Less than one dozen of these turbines have been manufactured, and only one machine in Kotzebue has been in commercial production for more than one year. The Entegrity, Vestas, and Fuhrlander wind turbines have induction generators which require reactive power but generate real power. At high penetration levels, the resulting positive real power (kW) and negative reactive po wer (kVAR) contributions to the grid must be taken into consideration as the ratio of real to reactive power must be maintained at an acceptable level with synchronous behavior. Starting the induction machines requires an inrush current to energize the generator. The motor’s speed /torque require current. Anytime this current can be eliminated or reduced, power factor is improved. Components such as the dynamic grid interface, synchronous condensers, power factor correction capacitors, and other components are added to provide VAR support at high penetration levels. The Vestas and Fuhrlander machines come with soft start power correction capacitors to reduce in rush current requirements. Uncorrected poor power factor can cause problems for the electrical system especially during periods of high wind and low load. Consequently, special care must be taken in the design and selection and control of wind diesel components, especially in high penetration applications. Both induction and direct drive turbine options are generally suitable for use in a wind diesel power system. At higher penetration levels, either wind-diesel system will require rapidly acting demand managed devices to balance either sudden increases or decreases in wind turbine output. Rapid control of real and reactive power is necessary for grid stability. Power electronic, fast acting dumploads and blade pitching, where available, are currently being used successfully and are being proposed for this project. According to the manufacturer of the Northwind 100, the company is planning to develop features to limit power output at the turbine. Fuel savings: The fuel, equipment, and operating costs, as well as wind resource information, and electric and thermal load data were incorporated into the HOMER model (www.nrel.gov/homer). HOMER is a widely used hybrid system simulation model developed by the National Renewable Energy Laboratory to screen various hybrid system design options. Construction cost estimates were developed based on current construction practice and prices of turbines were provided by the suppliers. In this instance, HOMER simulates the hour-by-hour operation of a straight diesel and a wind diesel power system, tallying the energy output, hours of operation, and fuel consumption of each system component and accounting for any shortfall in the system’s ability to provide sufficient electricity, spinning reserve, and heat. HOMER uses this Pilot Point Community Energy Plan October 2008 39 information along with capital cost estimates to assess the economic feasibility of various system configurations. The analysis calculates the operating cost, the replacement interval for each system component, and the resulting life cycle cost over the lifetime of the project for each possible configuration. HOMER models many system configurations and rank them by life cycle cost. Inputs in HOMER can then be changed to perform sensitivity analyses which assess the effects of changes or uncertainty in key inputs. In this analysis the wind resource and fuel price were varied to determine their effect on the financial feasibility. The results of this analysis are discussed below, and the low load diesel high penetration architecture using three Vestas V-15, 65 kW wind turbines system is proposed based on cost- effectiveness, simplicity, and operating experience. As better resource and load and cost data become available, the feasibility analysis can be rerun. One factor stands out as the most highly variable and that is the cost of the wind turbine foundation. Until the geotechnical analysis at the site is completed, a more accurate estimate of foundation costs is not possible. The HOMER modeling results were used to estimate fuel savings over the life of the project in which through experience in other wind projects throughout the world varies between 15 and 25 years. Practical experience indicates that after 15 years more efficient technology and methods will be available and the existing project will likely be replaced or upgraded. System configurations modeled: The schematic diagram of the system in HOMER appears below. In systems that include wind turbines, the excess wind power is used to serve the thermal load via a generic electric boiler. A total capital cost is calculated at $200,000 for the electric boiler, boiler-grid interface, and the necessary controls and integration to capture the excess energy. This capital cost is conservative. The schematic also shows the use of the most efficient combination of diesel generators to meet the wide variations in the load. Figure 9-Homer System Model Schematic Pilot Point Community Energy Plan October 2008 40 Preliminary Wind Feasibility: HOMER system optimization results are presented in Table 4. This table compares the wind energy production and fuel savings resulting from the addition of 1, 2, or 3 wind turbines of three types: the Vestas V15 - 35kW, the Vestas V15 - 65 kW, and the Bergey Excel-S. These results were used to establish the baseline sensitivity case where the average wind speed at 80 feet is 6.55 m/s. All wind turbines are modeled with a hub height of 80 feet. The table indicates that fitting the existing diesel generators for operation for load setpoint operation, installation of three Vestas V-15 65 wind turbines, and the addition of a stand alone dynamic heat recovery boiler perhaps at the school. The three turbine configuration offers a maximum conceptual fuel savings of nearly 21,800 gallons of fuel split between electricity generation (12,800 gallons) and heating fuel (8,900 gallons). At $3.50 per gallon this amount of fuel savings is equivalent to $ 76,300 which would be offset by wind system maintenance costs. The maintenance costs calculated are Pilot Point Community Energy Plan October 2008 41 based on a single stand alone turbine and are therefore very conservatively estimated for the three turbine s at $16,000 annually. Table 7 – Wind Energy Production, Fuel Consumption, and Fuel Savings for Base Case Scenario # System Description Wind Diesel Fuel Consumption Diesel Fuel Consumption Diesel Fuel Savings Diesel Fuel Savings Energy Power Heating Total Power Heating Total Power Heating Total Power Heating Total Prod. (MWh/yr) (L/yr) (L/yr) (L/yr) (gal/yr) (gal/yr) (gal/yr) (gal/yr) (gal/yr) (gal/yr) (%) (%) (%) 1 Existing system n/a 125,751 183,571 309,322 33,224 48,500 81,723 n/a n/a n/a n/a n/a n/a 2 Add 1 Excel-S 20 119,894 183,570 303,464 31,676 48,499 80,175 1,547 0 1,548 5% 0% 2% 3 Add 2 Excel-S 40 114,386 183,503 297,889 30,221 48,482 78,703 3,003 18 3,021 9% 0% 4% 4 Add 3 Excel-S 60 109,774 183,095 292,869 29,002 48,374 77,376 4,221 126 4,347 13% 0% 5% 5 Add 1 V15 - 35 kW 129 95,873 180,828 276,701 25,330 47,775 73,105 7,894 725 8,618 24% 1% 11% 6 Add 2 V15 - 35 kW 258 87,328 168,389 255,717 23,072 44,489 67,561 10,151 4,011 14,162 31% 8% 17% 7 Add 3 V15 - 35 kW 387 75,530 156,314 231,844 19,955 41,298 61,253 13,268 7,201 20,470 40% 15% 25% 8 Add 1 V15 - 65 kW 146 98,980 177,161 276,141 26,151 46,806 72,957 7,073 1,694 8,766 21% 3% 11% 9 Add 2 V15 - 65 kW 293 86,175 163,657 249,832 22,768 43,238 66,006 10,456 5,261 15,717 31% 11% 19% 10 Add 3 V15 - 65 kW 216 77,024 149,603 226,627 20,350 39,525 59,875 12,874 8,974 21,848 39% 19% 27% The table shows maximum fuel savings to the utility would be derived from the installation of three V-15, 35kW wind turbines. These turbines capture more of the energy available at lower wind speeds. T hree V-15, 65 kW wind turbines would generate more kilowatt hours of electricity because they are able to capture the energy of higher wind speeds and thus, have more energy available for conversion to heat. These fuel displacements, if achievable, represent potential yearly costs savings to the community at an excess of $80,000. (12,870 gallons of diesel fuel at the powerplant plus 8970 gallons of displaced diesel fuel used for heating, 21,848 gallons x $3.68 = $ 80,400). Pilot Point Community Energy Plan October 2008 42 The following table 5 shows the economic results for several sensitivity cases, in which both the wind resource and the fuel prices are varied. Table 8 – Economic Results & Fuel Consumption for Several Sensitivity Cases # System Description Life Initial Levelized Cost Simple Diesel Fuel Consumption Total Cycle Capital Operating of Pay- Power Heating Total Fuel Cost Cost Cost Energy back Savings ($) ($) ($/yr) ($/kWh) (yrs) (gal/yr) (gal/yr) (gal/yr) Base case: Diesel fuel $3.50/gal, heating fuel $4.50/gal, wind speed 6.55 m/s 1 Existing system 4,738,560 0 370,682 0.393 n/a 33,224 48,500 81,723 n/a 2 Add 1 V15 - 35 kW 4,867,871 400,000 349,507 0.419 18.9 25,330 47,775 73,105 11% 3 Add 2 V15 - 35 kW 4,902,300 600,000 336,555 0.426 17.6 23,072 44,489 67,561 17% 4 Add 3 V15 - 35 kW 4,839,738 800,000 316,015 0.414 14.6 19,955 41,298 61,253 25% 5 Add 1 V15 - 65 kW 4,848,880 400,000 348,021 0.415 17.7 26,151 46,806 72,957 11% 6 Add 2 V15 - 65 kW 4,766,447 600,000 325,927 0.399 13.4 22,768 43,238 66,006 19% 7 Add 3 V15 - 65 kW 4,720,762 800,000 306,708 0.390 12.5 20,350 39,525 59,875 27% Sensitivity case #2: Fuel prices 20% above base case 1 Existing system 5,594,456 0 437,636 0.453 n/a 33,224 48,500 81,723 n/a 3 Add 1 V15 - 35 kW 5,644,761 400,000 410,280 0.463 14.6 25,330 47,775 73,105 11% 4 Add 2 V15 - 35 kW 5,621,136 600,000 392,787 0.459 13.4 23,072 44,489 67,561 17% 5 Add 3 V15 - 35 kW 5,493,937 800,000 367,191 0.433 11.4 19,955 41,298 61,253 25% 6 Add 1 V15 - 65 kW 5,621,963 400,000 408,497 0.459 13.7 26,151 46,806 72,957 11% 7 Add 2 V15 - 65 kW 5,468,160 600,000 380,820 0.428 10.6 22,768 43,238 66,006 19% 8 Add 3 V15 - 65 kW 5,358,077 800,000 356,563 0.406 9.9 20,350 39,525 59,875 27% Sensitivity case #3: Fuel prices 40% above base case 1 Existing system 6,448,005 0 504,406 0.513 n/a 33,224 48,500 81,723 n/a 3 Add 1 V15 - 35 kW 6,419,341 400,000 470,873 0.507 11.9 25,330 47,775 73,105 11% 4 Add 2 V15 - 35 kW 6,337,819 600,000 448,851 0.491 10.8 23,072 44,489 67,561 17% 5 Add 3 V15 - 35 kW 6,146,139 800,000 418,211 0.452 9.3 19,955 41,298 61,253 25% 6 Add 1 V15 - 65 kW 6,392,781 400,000 468,796 0.502 11.2 26,151 46,806 72,957 11% 7 Add 2 V15 - 65 kW 6,167,781 600,000 435,549 0.457 8.7 22,768 43,238 66,006 19% 8 Add 3 V15 - 65 kW 5,993,479 800,000 406,269 0.422 8.2 20,350 39,525 59,875 27% Pilot Point Community Energy Plan October 2008 43 Sensitivity case #4: Fuel prices 20% below base case 1 Existing system 3,882,665 0 303,728 0.333 n/a 33,224 48,500 81,723 n/a 3 Add 1 V15 - 35 kW 4,090,981 400,000 288,733 0.375 26.7 25,330 47,775 73,105 11% 4 Add 2 V15 - 35 kW 4,183,463 600,000 280,323 0.394 25.6 23,072 44,489 67,561 17% 5 Add 3 V15 - 35 kW 4,185,538 800,000 264,840 0.394 20.6 19,955 41,298 61,253 25% 6 Add 1 V15 - 65 kW 4,075,797 400,000 287,546 0.372 24.7 26,151 46,806 72,957 11% 7 Add 2 V15 - 65 kW 4,064,734 600,000 271,035 0.370 18.4 22,768 43,238 66,006 19% 8 Add 3 V15 - 65 kW 4,083,447 800,000 256,853 0.374 17.1 20,350 39,525 59,875 27% Sensitivity case #5: Average wind speed 10% above base case 1 Existing system 4,738,560 0 370,682 0.393 n/a 33,224 48,500 81,723 n/a 3 Add 1 V15 - 35 kW 4,815,410 400,000 345,403 0.409 15.8 24,444 47,559 72,003 12% 4 Add 2 V15 - 35 kW 4,811,898 600,000 329,483 0.408 14.6 22,236 43,614 65,850 19% 5 Add 3 V15 - 35 kW 4,671,865 800,000 302,883 0.380 11.8 18,427 40,012 58,440 28% 6 Add 1 V15 - 65 kW 4,767,599 400,000 341,663 0.399 13.8 25,171 46,174 71,345 13% 7 Add 2 V15 - 65 kW 4,580,989 600,000 311,420 0.361 10.1 21,090 41,741 62,831 23% 8 Add 3 V15 - 65 kW 4,470,096 800,000 287,100 0.339 9.6 18,454 37,201 55,656 32% 1 Existing system 4,738,560 0 370,682 0.393 n/a 33,224 48,500 81,723 n/a 3 Add 1 V15 - 35 kW 4,924,064 400,000 353,903 0.431 23.8 26,312 47,982 74,294 9% 4 Add 2 V15 - 35 kW 4,998,486 600,000 344,079 0.446 22.6 24,023 45,387 69,410 15% 5 Add 3 V15 - 35 kW 5,010,299 800,000 329,358 0.448 19.4 21,502 42,676 64,178 21% 6 Add 1 V15 - 65 kW 4,930,364 400,000 354,396 0.432 24.6 27,233 47,368 74,601 9% 7 Add 2 V15 - 65 kW 4,945,832 600,000 339,960 0.435 19.5 24,501 44,636 69,137 15% 8 Add 3 V15 - 65 kW 4,972,264 800,000 326,383 0.440 18.1 22,388 41,750 64,138 22% Definition of terms in results tables: The life cycle cost is the total discounted present value of all costs incurred over the 25-year project lifetime, including initial capital costs, component replacement costs, O&M costs, and fuel costs. The levelized operating cost is the annualized value of all non-capital costs (actual operating costs vary from year to year depending on whether, for example, a wind turbine needs replacement that year). The levelized cost of energy is the average total cost per kWh produced by the system. The diesel savings is the percentage reduction in annual diesel fuel consumption compared t o the existing system. The simple payback of a system configuration is equal to its initial capital cost divided by its savings in levelized operating costs. Pilot Point Community Energy Plan October 2008 44 Wind diesel system control configuration The proposed wind turbine for this project is a remanufactured Vestas V-15, this turbine was originally manufactured as the V15 by Vestas Wind Systems A/S of Randers, Denmark. The E15 is rated at 65 kW output (three phase) with maximum power output of approximately 75 kW in standard density air. The planned project scenario is to install three turbines in a high- medium-penetration wind/diesel hybrid system. Because the average village electric load is relatively small – approximately 40 kW – and a single turbine at rated power is capable of one hundred plus percent wind penetration. The wind data indicates that this rarely occurs, however, design measures must be taken to maintain power system stability. For this reason, the amount of wind ener gy instantaneously substituted for diesel generation would be limited by the diesel plant control system to one third to one half the rated power output of the smallest diesel generator in the power plant. This is to ensure that a diesel generator is always operating in order to provide voltage and frequency stability. The smallest engine generator in the power plant would be a 64 kW electronically fuel injected John Deere. This unit should be able to operate efficiently at partial loading and accept a step load of at 50% or more of its rated capacity. When electrical demand is light the 64 kW diesel generator would be operating. If the engine generator is equipped with an engine generator controller (GSS), whenever wind energy was available, the SMS supervisory controller would select the most efficient engine generator to operate (most often the 64 kW machine) and issue a low limit setpoint to the generators so that no more than 20 kW to 30 kW (25 to 50% of the smallest machine’s rated capacity) of diesel output would be supplied to the village feeder line(s). The remaining electric power generated – up to 150 kW of wind energy, depending on the available wind energy – will be directed by the Boiler Grid Interface and supplemental energy loads, such as Thermal Storage heaters in individual homes or for charging batteries. The Wind Turbine controller has a Supervisory Control and Data Acquisition (SCADA) System which will allow remote diagnosis and alarming of system problems so that that downtime is kept to a minimum. The components could be integrated into the existing power plant or included in the system upgrade. Along with the wind turbine controllers(WTC) and the Boiler Grid Interface (BGI), the new controls will form a hybrid wind-diesel control backbone which may be easily expanded, if desired, by adding incremental wind, diesels, power conditioning equipment, or additional loads. These changes would be allowed by the use of a flexible proven diesel plant control system which makes possible economical use of excess wind energy to reduce dependency on high fu el costs. The control system will be designed to accommodate significant increases or decreases in community load. Pilot Point Community Energy Plan October 2008 45 The HOMER analysis uses existing data to estimate the amount of energy in the system during any one hour period. It is not a dynamic simulation that looks at the instantaneous stability of the system. The HOMER analysis suggests that the system can accommodate three V-15 65kW wind turbines. Higher wind penetration is achieved using an acceptably sized electric load with a Boiler Grid Interface (BGI). The BGI and its boiler loads can be controlled in their power demand and thus very rapidly balance the power system as wind power and electric load fluctuate. The BGI serves three primary purposes- dynamic readjustment of wind turbine and diesel load setpoints, improved power quality through the reconstruction of distorted electrical waveform s and the provision of reactive power support for motor and wind turbines. The BGI allows more wind energy for useful purposes (e.g., heating, operating motors, pumps, charging batteries, etc). During times of collapsing wind power generation, the BGI is able to keep energy buffer loads to a minimum and follows the load very closely with the ability to react very quickly (sub cycle) to loss of wind or sudden increase in consumer load. The BGI acts as an extremely fast acting dump load to decrease load and adjust the power factor, thus lowering the power demand on the system and balancing the energy generation to the demand through direct frequency control. In addition, components like the BGI improve the grid quality by providing reactive power or voltage level stabilization, which is especially important in periods of high wind turbine output and low diesel loading. When the diesel power station operates in parallel with the Wind Turbine Generators, the diesel power station operates in isochronous control mode with the WTG running as a negative load. The dynamic Grid Interface (in this case a Boiler Grid Interface, 140 kW) is coupled to electric heaters or other major loads providing precise dynamic control of the frequency, intermittent loads, and power factor to compensate for fluctuations in the generation/demand system, thus stabilizing the grid. In future applications, a supervisory master controller tracks the available wind power and engine output along with load demand and, upon meeting preset criteria for changing conditions, will automatically carry out instructions with safety margins such as selecting, turning engines on/off, managing heat recovery loads, and shutting wind turbines on and off. It is assumed that the power lines in the village are currently able to handle the generated power coming from the WTG’s at the point of common coupling. The WTG’s are capable of supplying sufficient fault current for protection devices to operate appropriately. It is possible to construct the proposed wind project in a phased manner. Assuming proper control and stabilization components are added to the power system then any number of wind turbines can be added, as funding becomes available. The HOMER analysis suggests three V15-65kW wind turbines. This result is based on the available wind and load data. Pilot Point Community Energy Plan October 2008 46 The HOMER analysis indicates that the wind turbine selected must be able to make use of the energy available at lower average wind speeds. The larger rotor diameter of the Vestas machine is better able to do this than the smaller Bergey machines. The available wind data also indicates that any turbine would be operat ing most of the time however, at less than rated capacity with full output of the turbines occurring only at wind speeds reaching 35 mph. The drawing below is for a scalable village wind diesel control system, and shows how the components in the powerhouse would be configured to operate with two generator sets. Figure 10 Wind Diesel Power System Integration: This proposed design builds upon the capabilities of the existing power station as well as the proposed new plant upgrades. The power electronics and controls for the generator set prevent reverse power conditions which can occur when the amount of wind generated energy exceeds the capacity of the diesel generators and fouling conditions during extended low load operations. The designs enable the diesel plant to operate at low load increasing the instantaneous proportion of wind energy while decreasing fuel usage. A remote heat recovery boiler will be placed at a remote location such as the school would be used to recover excess wind energy. In this configuration the majority of the wind energy is captured as high value electricity and a much smaller proportion is captured as heat. Unlike other high penetration wind Pilot Point Community Energy Plan October 2008 47 diesel systems, this simple design does not require complicated and expensive energy storage or large excess (150 to 400%) of installed wind capacity to generate significant fuel savings. It is important to note that while this system proposes to use three 65kW wind turbines, modeling studies indicate that these turbines have capacity factors of less than 25%. This implies that the average output from each turbine is about 15kW. More precise data and detailed system modeling is needed to make more accurate predictions however, the wind data indicates that much of the wind energy will be captured at speeds much lower than rated capacity. Alternate Wind System Configuration: Depending on the availability of funds, an intermediate and less effective wind diesel configuration is possible.This system could be considered a first step in development of a high penetration wind diesel system. This system was proposed for use in Kokhanok because it was designed to operate in the absence of advanced diesel plant automation. This system is proposed only as an alternative to full integration of wind into the diesel plant. Like the previous configuration, this system utilizes the Vestas V-15 wind turbine as the basis of design. However, in this application the amount of wind energy made available to the grid is restricted to a peak output through a separate wind turbine controller. This is less than an ideal usage of wind energy which would eventually require a power plant control system modification or replacement to allow 100 percent wind penetration. Figure 11 V-15 Normal Power curve Pilot Point Community Energy Plan October 2008 48 This option assumes that funds are available to install only one wind turbine, and that the control of that turbine cannot be fully integrated into the powersystem control. Control of the wind-diesel system is proposed through the use of a setpoint limiter to cap the wind turbine power output to the village electrical system in periods of high winds. As in the previous wind diesel architecture, excess wind power generated would be diverted by a dynamic boiler grid interface (BGI) to the heat recovery boiler (up to 100 kW power output). In this situation, the wind turbine power curve was modified with a power output limit of 30 kW (see modified E15 power curve below). Figure 12 V-15 Power limited power curve Power Control System Details: The proposed design calls for using a simple set point controller and boiler grid interface, which is designed to limit the output of the wind turbine into the grid. This feature is added in order to reduce the amount of wind energy instability that can be introduced into the grid in periods when the electrical demand is very low and wind output is very high. Although it is possible to provide a controller for the wind turbines which diverts energy into the storage medium, to achieve wind penetration into a smaller grid, the Station Management Control System is needed to trigger the various diesel generators to start and stop. The SMS also issues power set points for each component in the system to engage enable/disable commands to the wind turbines as well as control demand managed devices, to be most effective. This control scenario assumes that diesel Generator Controllers (GSC) will be used for each diesel generator for control and Pilot Point Community Energy Plan October 2008 49 protection of each diesel engine and generator. The wind turbines would be supplied with a separate wind turbine controller (WTC). The WTC communicates via radio Ethernet modem or copper/fiber optic cable with the dynamic boiler grid interface (BGI) controller and the SMS controller to enable Thermal Storage routines. The setpoint on the BGI controller is configurable by the operator and can be changed depending on the system requirements. Alternatively it may be possible to use thermal storage devices and powerline carrier signals to activate th e storage devices. However, exploring this possibility further would require additional design investigations.The powerline carrier would be needed to be activated by some supervisory controller, either at the wind turbine or the powerplant. Assumptions with Respect to Associated Equipment: Diesel Operation: Prolonged operation of any diesel engine for extended periods at low load can result in ‘slobbering” or wet stacking, carbon buildup, and glazing of cylinder walls from unburned fuel. Powercorp has successfully modified a number of generators to operate at low loads and low fuel consumption for extended periods of time. The main features of the conversion will consist of the addition of a boiler and boiler grid interface to provide reverse power protection to absorb wind gusts when operating at near zero kW, and to increase operating temperatures to eliminate cylinder glazing and wet stacking. The inverter and controls will be installed in the existing powerplant. There is sufficient room to install a heat recovery boiler and incorporate that with the plant heat recovery system. The electronic grid interface is wired to the generators and connected directly to the plant bus. Under normal conditions, a diesel configured for low load behaves like any other diesel generator, with the added benefit of very high efficiency. In all situations, the diesel gensets will operate in isochronous mode, attempting to maintain the nominal frequency of the network. During periods of low-load or high renewable penetration, the Station Controller can be programmed to allow the running low load configured diesels to run down to 5% of their rated load. During low-load operation, especially with wind turbines, the Low Load Diesel may be forced to use its dynamic inverter grid interface to prevent the generator from being pushed into reverse power operations. Control, fuel management, and injection of additional heat Pilot Point Community Energy Plan October 2008 50 modifications are made so that efficient low load operation can be maintained indefinitely, even with frequent operations of the grid interface, and fluctuations in the wind plant output. The existing diesel gensets should be examined for their ability to accept a large step-load response. The overall wind diesel system should be configured to enable frequency within 5Hz and voltage within 4% during a single step -load. The recovery from the single step load operation to steady-state operation (1% voltage and 1Hz frequency regulation) occurs within 5 seconds and is made possible through the boosts available from the dynamic response of the grid interface, and the remote boiler load. Experience has shown that the instantaneous total loss of all power from multiple turbines is an unlikely event. However, the control set points would be adjusted with the various diesel genset configurations to enable the parallel operation of either low load diesel to survive (non-stalling) a specific single step-load which is to say no larger than the loss of two turbines at half output, a 30 to 50 kW or similar increase in load from a 5% low operating threshold. As a rule the performance of each wind diesel system and each model of low load diesel is slightly different. This is dependent upon many factors from frequency and site rating conditions to wind and load characteristics. Also note that EPA1 requirements may require the reduction of the performance of the diesel machine to meet environmental standards. A period of commissioning and tuning can be expected to establish optimal system set points and operational thresholds. Boiler Grid Interface: The proposed wind diesel system will require at least one fast reacting dynamic boiler grid interface operating a remote heat recovery boiler. This Boiler Grid Interface is sized to receive up to 100 kW of excess wind energy, and can be placed anywhere on the electrical grid. The Boiler Grid Interface has three distinct roles: 1. To provide a demand managed device capable of delivering heat to a heating system, either a boiler or a district heating loop in a complimentary manner to the availability of the wind energy. 2. To provide frequency stabilization through the high speed frequency monitoring and the rapid adjustment of load from the boiler grid interface. 3. To provide a fully adjustable load with small 100W steps and an adjustable power factor without inducing damaging harmonics into the power system. Operation: Pilot Point Community Energy Plan October 2008 51 The temperature controller in the Boiler Grid Interface device monitors the temperature of the loop and makes requests to the power station master controller for power to maintain the temperature. The power station master controller sends back a power set-point which the Boiler Grid Interface is to maintain long-term. This parameter is based on the amount of uncommitted wind power available on the system. If the frequency of the grid moves outside of acceptable limits, the Boiler Grid Interface will automatically adjust the amount of power it is drawing, based on a sliding linear scale in an attempt to maintain control over the frequency. Once the frequency is back within acceptable limits, the Boiler Grid Interface returns to its original power set-point. If the frequency does not return within acceptable limits over a period of approximately 2 seconds, the power station master controller will take additional action (such as modifying the power demand of the Boiler Grid Interface, starting additi onal generator sets, or disconnecting Demand Managed Devices) to rectify the situation. Method of Power Control The Boiler Grid Interface uses IGBT technology to meet the following competing goals: 1. Fully adjustable 0-100% load control in steps of approximately 0.025% 2. Fast response time, 0-100% in less than 1/180th of a second. 3. Exceptional power quality, with the option to actively improve the voltage waveform at the expense of maximum load sizing. The IGBT based technology can offer such fast power contr ol due to its ability to modify the current draw at any point in the cycle, whether it be mid-cycle or not. This feature also allows the IGBT based Boiler Grid Interface to draw current at a pre-specified power factor. This feature will assist the diesel generators to support any low power factor loads that may be encountered. This compares with standard SCR load control technology which offers: 1. Fully adjustable 0-100% load control. 2. Fast response time, 0-100% in 1/60th of a second or so, depending on control technique. 3. Poor power quality, introducing damaging harmonics into the power system. Displacing residential heating fuel Electric Thermal Storage Heating Pilot Point Community Energy Plan October 2008 52 There is typically a good match between the need of heat and the availability of excess wind ene rgy. This energy can be used to offset diesel fuel used for heating. A practical way of capturing this energy may be to use Electric Thermal Storage (ETS) heaters which can be located throughout the community and used to capture excess wind energy. Since heating fuel accounts for the largest energy usage in the community, and greatest use of diesel fuel, capturing excess wind energy allows the utility to expand its community energy market share and offer savings to its customers. The complete system consists of ETS heater, electrical connection and metering/signaling system. Well insulated units are able to store heat for several days between charging and can be sized to supplement existing heating systems or as a stand-alone unit able to provide heat on the coldest, windiest days. The units work by using electric heating elements which lie within high density ceramic bricks or in hot water storage tanks. The ceramic brick systems have been used for over 50 years in residences and small business in Europe, and were introduced by utilities in the U.S. around 1970. The stoves are compact and the bricks are able to store large amounts of heat for extended periods of time. During periods when excess wind is available, and energy costs are lower, the heating elements can be activated by the utility, usually through the metering or power line controllers activated by the powerhouse supervisory controller. The stored heat is discharged from the units with thermostatically controlled fans. The units are well insulated and many hours of heat energy can be stored when the wind is not available. Several suppliers offer a wide variety of models including room units, forced air and hydronotic units, as well as peak control devices. The units come in various sizes and are specified by kilowatt ratings from 1.5 to 40 kW. Charging is done at 240, 208, and 277 VAC. Smaller units are available in a 1.3 kW input with a 120 V plug in cord. The units weigh from around 200 to 1000 lbs, depending on the amount of energy storage required. The units are compact designed to be mounted about 2 inches from a wall and measure from 30 to 60 inches in length, 24.5 inches in height and 12 inches in depth. Electric Thermal Storage (ETS) is a heat storage technology that can reduc e home heating costs where time-of-use (TOU) or low, off-peak rates are offered. Where such rates are available, electricity is most expensive during the day- time hours when the demand for power is the highest. ETS shifts the home's heating load from the h igher-cost, on-peak hours to the less-expensive, off-peak hours thereby reducing electricity costs. Pilot Point Community Energy Plan October 2008 53 In the most common ETS systems, heat produced with electricity during off-peak times is stored in dense ceramic bricks. When heat is needed, a blower moves the heat from the bricks to the living space. In addition to individual room heating units, other ETS products available today include heat pump boosters, hydronic heating systems and forced air furnaces. In recent years, as the installation of heat pumps in colder climates has grown, ETS is finding a place helping them attain the optimal economical operation. Heat pumps provide extremely high energy efficiencies, but as outdoor temperatures fall, so does their efficiency. At some point the heat pump can no longer keep the home at a comfortable temperature on its own and a supplemental or back-up heat source is needed. When the back-up is provided by resistance electric heat, the resistance heat uses the standard electric rate, which is generally two times higher than the off-peak rate. Using ETS, which has stored less-expensive heat produced off-peak, as a heat pump booster replaces the need for direct resistance heat at times when prices are higher. The heat pump booster can also deliver a higher level of constant comfort in the home by continually monitoring duct temperatures and injecting as much heat as necessary to keep the home comfortable. ETS can make electric heating cost-competitive with fossil fuels. Where affordable, off-peak electric rates are offered, customers may be able to save significant money by converting to ETS heating in lieu of their propane heaters, natural gas heaters, wood stoves or fire places. The savings using the ETS system are largely influenced by three factors - 1. Pilot Point Community Energy Plan October 2008 54 The differential between the utility's on-peak and off-peak rates, 2. The length of time each day that is off -peak, and 3. The annual amount of home heating needed. ETS System Installed with a Heat Pump Heat pump systems are known as one of the most efficient methods of heating and cooling. Using an ETS unit to provide the supplemental heat needed with a heat pump at low outdoor temperatures instead of the more commonly used direct electric strip heat allows the heat pump's high efficiency to be combined with the advantage of off-peak electric rates. In heat pump applications, the ETS unit replaces the resistance strip heat or other back -up heat, with low-cost, off-peak stored heat. As outside temperatures drop, the stored heat in the ETS unit is used in conjunction with the heat pump's heating capacity to satisfy comfort requirements. During on-peak hours or when the demand for heat is at the point where the heat pump alone cannot satisfy the heating requirements, the stored heat is used to supplement the heat pump. Using an ETS unit allows the heat pump's high efficiency to be used even during times of cooler outdoor temperatures. The Heat Pump/ETS system benefits:  Provides comfort 24 hours a day  Provides for a high efficiency, low cost heating and cooling system  Optimizes system performance by allowing the heat pump's efficiency to be fully utilized  Eliminates the cool discharge air temperatures associated with older model heat pump systems during times of low outdoor temperatures. Pilot Point Community Energy Plan October 2008 55 The heat pump/ETS combination, when used with off -peak electric rates, is a more economical heating system than a heat pump with electric strip heat. ETS How the System Works 1. The room thermostat in the home is set to desired comfort level. If room temperature decreases below the room thermostat set point, the system is energized to deliver heat. 2. Upon a heat call from the room thermostat, the heat pump's outdoor compressor unit is energized and warms the refrigerant coil in the heat pump unit. At the same time, the ETS unit's supply-side blower is energized. 3. The supply-side blower draws air from the home (shown at 68° F) across the air filter and the heat pump's refrigerant coil, extracting heat from the coil as it passes through. 4. A sensor monitors the temperature of the air as it leaves the coil. If the air temperature is warm enough to be comfortable for people in the space, generally 90° F or higher, the supply air blower simply delivers the warm heat into the home through the supply air duct. Air temperature after passing over the coil in the diagram is shown at 85° F. 5. If air temperature after the heat pump coil is below a comfortable level (generally less than 90° F), the ETS unit's core blower will modulate low cost, off-peak stored heat into the duct stream so comfortable heat (generally 90° F or higher) can be delivered into the home. In the diagram, the conditioned air is shown at 95° F. Pilot Point Community Energy Plan October 2008 56 Because heat pumps generally have an operating efficiency of 150 to 300 percent (depending mostly on outdoor temperature), the ETS system first uses the heating ability of the heat pump. If the heat pump doesn't have the ability to satisfy space heating requirements, the ETS system starts working with the heat pump, using low-cost, off-peak energy to provide comfort. Combining the heat pump's efficiency with the off -peak ETS system yields comfort at a low operating cost. ETS Room Heating Units ETS room units can be installed to heat individual rooms, such as remote or added spaces, or to supplement the heating in otherwise hard-to-heat rooms. Room units are non-ducted heaters designed to heat just the room or area where they are located. These heaters can be used in new construction or as a retrofit or supplement to an existing heating system. The ETS equipment is easy to operate and requires very little maintenance. When the unit's built-in thermostat calls for heat, a fan comes on to circulate air across warm ceramic bricks. The bricks are warm having been heated electrically using resistance during the off -peak period when electricity prices are lower. Various sizes of room units are available typically ranging from 1 kW, 120V - plug-in units to larger 10kW, 240V models. Sizing of the units is important because once an ETS system runs out of heat generated with off-peak electricity, it should wait until the off-peak period occurs again to regenerate. Pilot Point Community Energy Plan October 2008 57 Heat Storage Control The amount of heat stored in the brick core is regulated manually by the user or automatically in relation to the outdoor temperature (stores more in colder weather) and the available wind energy. During a charging period (windy period) the heater stores the appropriate amount of heat needed to satisfy the comfort requirements. System Control Thermal Energy Storage equipment is available which interfaces with various on-peak and off-peak signaling devices to regulate either energy usage or charging of the heating equipment. The methods of control include utility contr ol switches, utility meters, and time clocks. Typically, a smart utility meter is used to record and regulate when excess wind energy is available to ensure energy savings. The desired room comfort level is regulated by the heater’s built in thermostat using a blend of radiant heat from the warm heater surface and convection heat from the fan as it circulates the stored heat in the room. Operating Costs In order to compare the price of wind/green heat to the price of stove oil or diesel fuel, it is necessary to compare equipment efficiency, energy content cost, and monthly service charges. The utility would likely have a basic charge to cover the cost of installed equipment and service fees with the cost of energy as an additional charge. Electric heat ing system ranges can be 100% efficient, while oil heating system efficiencies can range from 60 to 90% range. Cost comparisons must take into account actual energy costs. Excess wind energy would be worth around $.10 per kilowatt hour as diesel fuel costs approach $5.00 per gallon. Alternative fuel price to using green electric rate conversion formula: (Fuel Price) + (Efficiency) x (341,300) / (Btu Heat Content) = Electric Rate Example of $ 4. 00 per gallon diesel fuel ( $4.00) x (85%) x (341,300)/(13,000) = $0.09/kWh Caution: The current residential rate equates to an equivalent diesel price of $13.45 per gallon. At this rate it would make little sense for a customer to convert to electric heat from diesel fuel. A sample alternative fuel price conversion formula : Pilot Point Community Energy Plan October 2008 58 (Electric Rate) x (Efficiency) x (Btu Heat Content) /(341,300) ($.40) x ( 85%) x (136,000 Btu/gal) / (341,300) = $ 13.45/gallon Advanced Storage Applications: It is not out of the question to plan to use excess wind energy to displace fossil fuels used for transportation. Plug in electric vehicles, PHEV’s, are being introduced by major automotive manufacturers ( Ford, GM, Toyota). They are working on a light duty hybrid electric vehicle (PHEV), which can be plugged into household wall sockets to charge batteries. Some of these cars will be hybrids with gasoline engines as back up and others may be all battery power. Excess wind power could be directed to charge these systems instead of producing heat. These types of vehicles would be especially useful in small communities where driving distances are short. Investment in this technology is quite large and is being driven by the rising cost of gasoline, incentives to make use of excess renewable and off-peak power, and a worldwide drive to reduce green house gas emissions. California is mandating vehicles with Partial Zero Emissions Vehicles and, according to the US DOE, major use of PHEV’s has the potential to reduce emissions nation-wide by vehicles 27%. While there are no firm commitments by manufacturers, perspectives appear to have changed and costs targets are reported at $.03 per mile and battery lifetimes of 8 to 10 years. Concept cars are scheduled for 2007 and some predictions are that PHEV’s will be mainstreamed as early as 2010. The cars will be factory built and dealer supported. Conversion kits for existing cars are also beginning to appear on the market. At the moment, PHEV designs hinge on battery cost and performance. Energy storage capacities are reported from 7.3 (Hymotion) kWhrs to 56 kWhrs (Tesla), but in general vehicles could expect to store between 10 and 20 kW hrs of electricity and travel between 40 and 250 miles between charges. Electric transportation for th e community could be affordable if excess wind energy could be used to charge vehicles and if the power system control design is sufficiently intelligent to manage the energy costs effectively. Energy Storage (Batteries/ Flywheels): Short term energy storage could be used to enable diesel off operation, for peak shaving to increase diesel efficiency and for storing excess generation. A third application might be to have the energy storage distributed at customer locations, which would assure energy system reliability, eliminate the need for back up generators, and enable customer based plug and play applications of wind and photovoltaic systems. Energy storage offers many options. There are two predominant forms of energy storage, batteries and the flywheel. . Pilot Point Community Energy Plan October 2008 59 The proposed wind diesel architecture uses diesel gensets operating at lower load with frequency control that employs fast acting load management. This system design uses power electronics conversion technology as the basis for advanced diesel off applications which use battery or flywheel energy storage. The primary obstacles to energy storage use are technical and economic. Current battery technology is limited by number of charge discharge cycles. Fluctuating wind turbine output requires repeated cycling of battery systems. This reduces system life and thus is poorly suited for frequency control. Current versions of the flywheel will allow up to 500 kW of wind turbine energy to be lost from the grid in one step and provide up to 30 seconds of full grid support. This is sufficient time to start and bring diese l capacity on line. Under normal operating conditions the flywheel turns variable wind energy into firm power. Flywheels cope well with frequency change but, presently available system costs are in the range of $750,000. Flywheel technology is evolving and costs will come down as production costs come down and markets respond. By themselves, flywheels are capable of basic stabilization of both the voltage and frequency of the power system without any additional information from external sources. This is achieved by monitoring the frequency and voltage of the grid and using the flywheel interfaced to power-electronics to import and export real power to condition frequency variations and reactive power to condition voltage variations. This aspect of the system design deserves further investigation, especially a s battery technology evolves. An alternative is to deploy battery energy storage in distributed appliances. This would consist of batteries, metering, interconnection and conversion devices located at customer facilities. The benefits of such an application would enable utilities to store excess wind energy as well as reshape the load duration curve by deploying stored power during peak periods. When combined with the ability to reduce customers’ non-essential loads at any time, batteries could be used to optimize existing base-load generation assets and provide the customer a source of backup power while paving the way for the customer use of solar and wind energy sources. Training and Support: Wind turbines stand in the weather 24 hours a day, 365 days a year, ready to operate. Any piece of equipment that is called upon to operate everyday will require maintenance. To keep costs down and maintain performance it will be necessary for local operators will be trained in wind turbine and wind diesel operations and maintenance. Training will consist of a combination of classroom and hands on learning with instruction by qualified engineers and technicians. Training will be in four primary areas: safety, wind operations, diesel plant and power electronics, and system communications. The Vestas machines are remanufactured at the EMS facility in Howard South Dakota. Pilot Point personnel will attend an on site training course at the EMS facilities in South Dakota, where they will be trained in the operation and Pilot Point Community Energy Plan October 2008 60 maintenance of the V-15. This training will include hands on and classroom training on turbine installation, maintenance and operations. Two full days will be spent in the field with technicians and trainers to learn safety techniques and gain climbing certification. Three days of classroom and shop training will be spent on the wind turbine communications and controls. This training will be conducted at the operations and engineering c enter in Gary, South Dakota. The wind turbines and boiler grid interfaces come with 12 month parts and service warranties. Training of local personnel on the operation of the boiler grid interface and control system must be provided by the suppliers. Training on the wind turbines will take place during construction and operations. Formal classes should be held by the equipment representatives. Various specialists in wind turbine maintenance and operations are available to provide technical assistance in the maintenance, erection and training related to the wind turbines. Turbine Installation: Smaller turbines can be erected without the use of a crane by using a tiltup tower. The greatest unknown with respect to the installation of wind turbines is foundation type. The turbines will be installed on pile foundations and erected using tilt up towers. Compared to many or most potential wind power site locations in Alaska, Pilot Point does not present the usual construction difficulties of tundra and/or permafrost. The “soils” appear to be some gravels overlain with organic layers. Because of the immediate proximity to Bristol Bay, there is no permafrost anticipated at the site. Prior to final foundation design and of course prior to construction of the foundations a pit will be dug with a backhoe or excavator to a depth of several meters or so to verify presumed soil conditions and a foundation specifically engineered for the site. The community has a number of pieces of heavy equipment in the village. The desire would be to take advantage of on going construction activities to construct the wind turbines and to incorporate high-penetration wind-diesel system features into the powersystem upgrades. The wind project site should be selected by the community for a location which is far enough away from the residential buildings to minimize noise and visual impacts yet close enough to existing high voltage three-phase power lines to keep distribution construction to a minimum. Long-Term Operations and Maintenance: Pilot Point Community Energy Plan October 2008 61 A more detailed description of wind turbine maintenance is provided in the Appendices. With each major component long term maintenance agreements should be available from suppliers. All parts, service manuals , and after installation support for turbines and controls is available from various suppliers. Technical assistance for this proposed design is available from Anchorage office of Powercorp. Additionally, the wind turbines, generators, and other major components should be specified with advanced remote diagnostics capability through the supervisory system controller. Remote monitoring and diagnostics via phone modem or Ethernet connection significantly improves system performance and reduces the cost of service calls. Operations and maintenance requires resources. The wind system must be large enough to displace significant amounts of fuel to make maintaining the wind turbines worthwhile. With respect to operations and maintenance funding, large turbines are favored over small ones. Additional sources of revenue such as the sale of the environmental benefits generated by the turbines and sold as Green Tag can generate up to $30,000 for a proj ect such as this. This funding could go into an escrow account for operations and maintenance. NativeEnergy is one company which will buy the green tags once the project is constructed, however there are many others. Engineering and Permitting: Land for the project has been made available by the City of Pilot Point. Geotechnical conditions will dictate turbine foundation designs and confirm selected locations. All conceptual assumptions must be confirmed in the final designs. If federal funds are involved, permits will be required from the USFWS, Corp of Engineers, FAA and State permitting agencies. USFWS concerns are to increase the visibility of towers between 20 and 40 foot, and to maintain the towers to restrict avian strikes and kills. Fencing is required to monitor impacts as well as avian deterrent devices attached to the towers and guide wires. The site selected at Pilot Point for wind towers is off the avian flight patterns for migratory birds and away from the coastline to protect shore birds and seabirds such as eiders. Estimated Costs The following table is provided as an estimate of project costs for a three turbine high penetration system. This estimate assumes the use of injected grouted pile type foundations for the wind turbines, modifications to the communications and controls in the powerplant, and the use of existing diesel generators. This budget also includes a four pole line extension to the wind turbines but does not make provisions for access roads or decking to the turbines. This estimate is based on previous construction estimates. Pilot Point Community Energy Plan October 2008 62 Table 9 Three Turbine High Penetration Budget: Phase #1 – Engineering Amount Civil $ 40,000 Environmental $ 10,000 Mechanical $ 25,000 Electrical $ 40,000 PHASE #1 TOTAL: $ 115,000 Phase #2 – Procurement and Construction Wind Turbines, Tower & Materials $ 450,000 Integration, communications and control $ 350,000 Installation, Logistics & Labor $ 450,000 PHASE # 2 TOTAL $1,250,000 Phase #3 Reporting & Evaluation $ 20,000 PHASE TOTAL: $ 20,000 PROJECT TOTAL: $1,385,000 Table 10 Alternative Single Turbine Project Budget: Engineering and project management 115,000 Wind turbine V-15 F.O.B Anchorage 115,000 Controls Wind Boiler and Grid Interface 125,000 Misc materials foundation and powerline/tranformer 80,430 Labor 60,500 Freight 50,000 Equipment Rental 30,000 Pilot Point Community Energy Plan October 2008 63 Housing and transportation 10,000 Project Cost $585,930 Appendix Wind Turbines: Bergey Excel (10 KW): The Bergey Excel is a direct drive variable speed permanent magnet wind turbine, with a rotor diameter of 7 meters. The turbine produces 240 V, three-phase variable AC. Both the voltage and frequency of the power vary directly with wind speed. The power runs from the turbine to an inverter where the “wild” AC is grid-synchronized. From the inverter the system is wired to a fused service disconnect and production meter. From the production meter the wires run to a pole mount transformer. The Bergey turbine is a stall regulated machine with limited control, primarily to connect and disconnect the turbine to and from the grid. Full rated power is achieved at 35 mph. While this turbine has been suggested for use in wind-diesel applications, the energy output of the turbine is limited. The turbine is better suited to a small off -grid battery charging applications or connection to a large stable grid. Operators have reported problems with noise, poor power quality, and difficulties connecting to and maintaining a grid connection through the inverter to the weak diesel grid. According to the manufacturer this problem has been addressed. Nevertheless, due to its small size and limited energy output, this turbine is not recommended for further detailed design. Remanufactured Medium Sized Wind turbines: Serious consideration should be given to the use of the best of breed, remanufactured wind turbines. These machines are available as remanufactured only and available from a number of companies. It is important to understand the remanufacturing process. Typically, the machines will be provided as close to new as possible. A good remanufacturer will replace all wearable components, inspect and check all core components against original equipment specifications for correct dimensional tolerances, and make available all replacement parts as new or made to the same quality and in the same production process as original equipment. These machines are available with test reports and extended warranties which in some cases exceed the manufacturer specifications and original production standards . Pilot Point Community Energy Plan October 2008 64 The Vestas V-15: The V-15 wind turbine is a three bladed upwind turbine with a rotor diameter of 15 meters. The V-15 wind turbine captures wind energy and uses an induction generator connected to an electrical grid for generator excitation to generate electricity. The turbine comes in three generator configurations:  480 VAC Three phase with a rated output of 65 kW  208/240/480 VAC Three phase with a rated output of 35kW for low wind speed applications  240 VAC single phase with a rated output of 35 kW The wind turbine is autom atically started by the controller whenever the wind speed is determined, as measured by the anemometer, to be sufficient to generate electricity. The turbine is one of the most proven wind turbines available. The 15 meter diameter rotor uses a fixed pitch passive stall design and incorporates centrifugally actuated tip brakes to prevent over-speed. Stall is an aerodynamic property that occurs gradually over along the length of the blades when the wind speed reaches a level of 30 mph and above. The blades are constructed of reinforced fiberglass and are bolted to the hub via a flange. Power is transmitted through a gearbox, to the generator. The gearbox is a 3 stage parallel shaft type with a gear ratio of 1:22.4. It has a rated capacity of 137 kW with an input speed of 40 or 53 rpm and an output speed of 900 and 1200 rpm (depending on generator type). Pilot Point Community Energy Plan October 2008 65 Figure 13 Vestas Wind Turbine Pilot Point Community Energy Plan October 2008 66 Vestas V-27: The Vestas V-27 is the bigger sister of the Vestas V-15 turbine and is similar in many respects. The greatest difference is that the V-27 is a pitch regulated upwind wind turbine. The turbine has active yaw and a high speed rotor with three blades like the V-15 with another exception that power is transmitted from the rotor through a main dri ve shaft through a gear box to a double wound asynchronous induction generator for direct connection to the grid. The rotor has two different speeds depending on the number of generator poles which are connected. The two pole generator is used to capture additional energy at lower wind speeds. The turbine has pitchable blades which can be adjusted to a power setpoint. The turbine has a cut-in speed of 8.0 mph (1.5kw), and reaches rated output of 225 kW at 31 mph. The turbine comes with a tubular tower or lattice tower and an enclosed nacelle. This turbine is currently available as either new or remanufactured machines. The new machines are quite difficult to get and delivery dates are not available. The machine is being manufactured under license to Vestas RRB of Chenai,India. Various remanufacturers will quote supply of a V-27. Entegrity (AOC 15/50): The Entegrity (previously known as AOC 15/50) is a horizontal axis, three bladed, downwind, free yaw wind turbine with a nominal power rating of 65kW. The rotor diameter is 15 meters. The turbine is mounted on a truss tower with a standard height of 25 meters. The turbine achieves a power output of 50kW at 11.0 mps (24.5 mph) and a rated output of 64.9 kW at 16.5 mps. During the winter months in Alaska, under very cold temperatures and extremely high air densities, the Entegrity turbine typically exceeds its maximum power rating of 66kW. Currently, there are eighteen (18) Entegrity turbines installed in Alaska – twelve (12) in Kotzebue, four (4) in Selawik and two (2) in Wales. The Kotzebue turbines have been operating with over 90% availability since 1998. Common probl ems with this turbine have been unscheduled and frequent release of trip brakes, difficulty resetting of brakes, unnecessary energy consumption on start up, upwind operation, highly variable output during turbulent wind conditions, and slow service response, as well as inability to ship the turbines as complete and tested assemblies. These problems have plagued the cost and performance issues. The company is under new management and is making good progress at addressing these problems. New controller and tip brake designs have been introduced in Selawik and attention is being given to a number of other small Pilot Point Community Energy Plan October 2008 67 improvements. The elimination of the dynamic brake and repackaging of the turbine controller, as well as the development of various foundations, tower and erection systems have been proposed to further reduce installation costs. Northwind 100kW: The Northwind 100 is a horizontal axis, three bladed, upwind, fixed pitch, variable speed, yaw driven wind turbine with a nominal power rating of 100kW. The rotor diameter is either 19.1 meters or 20 meters. The turbine is mounted on an enclosed steel tower that allows access to the turbine and houses the system controller in the base. The turbine achieves a power output of 100kW at 15.5 mps (34.7 mph) and a maximum output of 102.5 kW at 17.1 mps (38.1 mph). During the winter months in Alaska under very cold temperatures and extremely high air densities, the Northwind 100 turbine typically exceeds its maximum power rating of 100kW. One unit has been operational in Kotzebue since 2000. The maximum observed power output has been 120kW. The turbine is variable speed, permanent magnet gene rator; the 3 phase AC power is conditioned through an inverter to produce energy of a specified voltage and frequency. The turbine is fixed pitch, and power output setpoint in the power conditioning system is not yet possible. Reported problems in Kotzebue have been minor with the failure of the control screen and yaw drive due to freezing. According to Kotzebue Electric, this turbine has been performing very well and is usually producing some amount of energy, even in very low winds. Fuhrlander FL30: The Fuhrlander FL30 is a horizontal axis, three bladed, upwind, fixed pitch, yaw driven wind turbine with a nominal power rating of 30kW. The turbine achieves a maximum power output of 33kW at 16 mps (35.8 mph). According to the supplier, one (1) turbine is scheduled for installation in the U.S. This turbine is manufactured by a well respected manufacturer in Germany and is anticipated to perform as described. There is little reported experience in the United States with this turbine. The machine is reported to be rugged and energy output estimates are favorable. Fuhrlander FL100: The Fuhrlander FL100 is a horizontal axis, three bladed, upwind, fixed pitch, yaw driven wind turbine with a nominal power rating of 100kW. The turbine achieves a maxim um power output of 125 kW at 14 mps (31.4 mph). According to the supplier, one (1) turbine is scheduled for installation in the U.S. Table 11: Wind Turbine Comparisons Pilot Point Community Energy Plan October 2008 68 Turbine Maintenance: Every wind turbine requires routine maintenance to maximize performance, maintain safety, and ensure a full operating life of the turbine. Excluding major component inspections and replacements, the annual cost of maintaining any of the candidate turbines can be estimated to be similar. The following basic maintenan ce schedules should be followed and apply to each of the turbines described above. Monthly Inspections:  Visually inspect turbine and site for obvious problems  Record meter and run time readings  Inspect for loose fasteners Bi-Annual Inspections (every 6 months):  Rotor Rotor fasteners are to be torqued and blades inspected and cleaned.  Drive Train IDescription Vestas V-15 (remanufactured ) Entegrity 15/50 Vestas V-27 (remanufactured) Northwind 100 Fuhrlander 100 Fuhrlander 250 kW Rating (kW) 65 (Max 75) 50 (Max 66) 225 (Max 250 kW) 100 (Max 120) 100 (Max 130) 250 (Max 300) Swept Area (W/m2) 176 176 133 284 346 706 Power Density (W/m2) 375 375 226 423 375 424 Weight (lbs) 22,000 14,000 50,380 30,000 60,000 90,640 Estimated Base Price FOB factory, with tower or North America $ 95,500 $120,000 $225,000 $350,000 $397,000 $ 550,000 Range of Estimated Installed Cost $175,000-$ 225,000 $200,000- $225,000 $525,000- $1,000,000 $600,000 - $ 800,000 $600,000 to $ 800,000 $880,000 to $ 1,200,000 Approx. Weeks to Delivery 12 -20 12 - 20 32 to 52 20 40 to 100 40 to 60 Pilot Point Community Energy Plan October 2008 69 Lubricate main shaft while rotating and check gearbox oil. Tighten seals and covers. Inspect and torque gearbox couplers. Add or remove gearbox jacket as required for season.  Generator Inspect for signs of overload and excessive heating. Torque mounting fasteners, insure all air inlet screens are open, clear, and or closed as appropriate for the season. Grease front and rear generator bearings, inspect cable terminations, and connections.  Yaw System Inspect, clean and grease.  Wind speed and direction Inspect, clean and adjust as needed.  Brake System Inspect brake pads for wear. Pads to be changed when there is 4mm or less of material left on the pad. Inspect excessive pad or disk wear. Inspect calipers, lines and hydraulic station and compete static pressure tests.  Tower Tower and man basket fasteners are to be checked in accordance with a torque list. A 10% torqu e check is recommended annually and all base nuts inspected for torque movement of torque marks, wear, or corrosion. Inspect and replace tower climbing pegs as needed. Inspect welds on tower slew ring. The safety cable should be thoroughly inspected along with it fasteners and welds on mounting brackets.  Controller System checks inspect wiring and connections. HOMER Input Summary Pilot Point Community Energy Plan October 2008 70 File name: Pilot Point old diesels rev2.hmr File version: 2.19 Author: Tom Lambert AC Load: Electric Load Data source: Pilot Point electric rev2.dmd Daily noise: 5.99% Hourly noise: 8.75% Scaled annual average: 1,062 kWh/d Scaled peak load: 75.6 kW Load factor: 0.585 AC Wind Turbine: Vestas V15 - 35 kW : Quantity Capital ($) Replacement ($) O&M ($/yr) 1 200,000 200,000 4,800 Quantities to consider: 0, 1, 2, 3 Lifetime: 15 yr Hub height: 24.4 m AC Wind Turbine: Vestas V15 - 65 kW : Quantity Capital ($) Replacement ($) O&M ($/yr) 1 200,000 200,000 4,800 Quantities to consider: 0, 1, 2, 3 Lifetime: 15 yr Hub height: 24.4 m Pilot Point Community Energy Plan October 2008 71 Wind Resource: Data, Pilot Point 80' synthetic.txt Month Wind Speed (m/s) Jan 5.05 Feb 6.75 Mar 5.82 Apr 5.94 May 5.37 Jun 5.16 Jul 4.86 Aug 5.59 Sep 4.68 Oct 5.80 Nov 5.44 Dec 7.27 Weibull k: 1.817 Autocorrelation factor: 0.881 Diurnal pattern strength: 0.1054 Hour of peak wind speed: 15 Scaled annual average: 6.55, 5.24, 5.90, 7.21, 7.86 m/s Anemometer height: 24.4 m Altitude: 0 m Wind shear profile: Power law Pilot Point Community Energy Plan October 2008 72 Power law exponent: 0.14 AC Generator: JD 64 kW Size (kW) Capital ($) Replacement ($) O&M ($/hr) 64.000 0 38,000 4.100 Sizes to consider: 64 kW Lifetime: 80,000 hrs Min. load ratio: 30% Heat recovery ratio: 0% Fuel used: Diesel Fuel curve intercept: 0.0373 L/hr/kW Fuel curve slope: 0.264 L/hr/kW AC Generator: Cat 113 kW : Size (kW) Capital ($) Replacement ($) O&M ($/hr) 113.000 0 70,000 5.600 Sizes to consider: 113 kW Lifetime: 80,000 hrs Min. load ratio: 30% Heat recovery ratio: 0% Fuel used: Diesel Fuel curve intercept: 0.08 L/hr/kW Fuel curve slope: 0.25 L/hr/kW Pilot Point Community Energy Plan October 2008 73 AC Generator: Cat 160 kW Size (kW) Capital ($) Replacement ($) O&M ($/hr) 160.000 0 99,000 6.900 Sizes to consider: 160 kW Lifetime: 80,000 hrs Min. load ratio: 30% Heat recovery ratio: 0% Fuel used: Diesel Fuel curve intercept: 0.08 L/hr/kW Fuel curve slope: 0.25 L/hr/kW Fuel: Diesel Price: $ 0.925, 0.740, 0.832, 1.017, 1.110, 1.202, 1.295/L Lower heating value: 43.2 MJ/kg Density: 820 kg/m3 Carbon content: 88.0% Sulfur content: 0.330% Fuel: Diesel2 Price: $ 1.189, 0.951, 1.070, 1.308, 1.427, 1.546, 1.664/L Lower heating value: 43.2 MJ/kg Density: 820 kg/m3 Carbon content: 88.0% Sulfur content: 0.330% Pilot Point Community Energy Plan October 2008 74 Economics Annual real interest rate: 6% Project lifetime: 25 yr Capacity shortage penalty: $ 0/kWh System fixed capital cost: $ 200,000, 0 System fixed O&M cost: $ 0/yr Generator control Check load following: Yes Check cycle charging: No Allow systems with multiple generators: Yes Allow multiple generators to operate simultaneously: Yes Allow systems with generator capacity less than peak load: Yes Emissions Carbon dioxide penalty: $ 0/t Carbon monoxide penalty: $ 0/t Unburned hydrocarbons penalty: $ 0/t Particulate matter penalty: $ 0/t Sulfur dioxide penalty: $ 0/t Nitrogen oxides penalty: $ 0/t Constraints Maximum annual capacity shortage: 0% Minimum renewable fraction: 0% Operating reserve as percentage of hourly load: 10% Operating reserve as percentage of peak load: 0% Pilot Point Community Energy Plan October 2008 75 Operating reserve as percentage of solar power output: 25% Operating reserve as percentage of wind power output: 50% Geothermal Potential Located along the “Ring of Fire” the Alaska Peninsula has no shortage of volcanoes nor geothermal activity. Although Pilot Point is located over thirty miles away from its nearest volcano, Chiginagak, there is geothermal activity (hot springs) near Painter Creek by Mother Goose Lake. Port Heiden has active geothermal potential from the Aniakchak Caldera and is actively pursuing geothermal as an alternative energy source. Naknek Electric is pursuing a large geothermal project that will supply the entire Bristol Bay Region. Powerlines would extend through Pilot Point possibly enroute to Port Heiden and Chignik and line maintenance would be accomplished with helicopters. The Electric Coop members have toured facilities in Iceland where the entire island is heated and powered with geothermal energy. The project will require a very large investment and may be years away. The Naknek Electric “White Paper” is featured below. Proposed Regional Geothermal Generation Project December 2007 Naknek Electric Association, Inc. (NEA) is exploring geothermal power production in an effort to improve its ability to provide reliable and affordable electricity. The cooperative faces an urgent need to identify sound alternatives to diesel generation due to the increasing and unpredictable costs of fossil fuels. These costs threaten the economic health and sustainability of the Bristol Bay and Lake Regions of western Alaska. Recently, the diesel fuel surcharge, which is reflected in the electric rate charged to NEA consumers, has increased by about 68% or more than $73.00 per month for a typical residential customer. Information indicates that development of geothermal power production will stabilize and lower electric rates in Naknek and throughout the region where approximately 6,500 people live in 25+ isolated rural communities. Pilot Point Community Energy Plan October 2008 76 Bristol Bay is considered the Sockeye Salmon capital of the world. In recent times, the harvest of Sockeye Salmon in a single summer topped 45 million fish. Since the area has a natural economic base, lowering the cost of electricity is expected to significantly improve the local economy. If energy costs can be reduced several seafood processors have indicated they would be interested in extending their seasons in the Bay to include secondary processing of salmon. NEA’s interest in geothermal power took root over a decade ago when the cooperative began researching local geothermal energy potential. It found considerable research data completed within the Katmai National Park and Preserve which warranted further exploration. The park boundary lies just a few miles from NEA’s electric lines. During preliminary discussions with federal officials, it appeared that gaining access to the identified potential resource through park and refuge lands would be excessively expensive and time consuming. NEA continued to watch for geothermal opportunities, and focused on improving diesel production efficiency and other efforts to stabilize electric rates. NEA found that today’s drilling technology supports the development of geothermal resources at approximate depths of 10,000 feet or more. Therefore, it may be possible to find a resource outside the national park and close to existing road and electric distribution infrastructure. NEA is currently assessing local geothermal resources, available geothermal power technologies and options for a transmission system that will extend the benefit of geothermal resource development to all communities in the region. Thus far, NEA has completed research, review, and assessment of thermal imagery map overlays, oil well production and log data, and regional faults and fractures data. It has also completed surface testing, which shows the presence of minerals indicative of an underlying geothermal resource, and has drilled three shallow test wells, reaching bedrock. NEA just finished its thermal probe testing, while seismic 3D modeling is currently still in progress. Data from both methods of analysis will be available in mid December of this year. NEA hopes the data provide d will assist in determining which site is optional for drilling a deep well of 10,000+ feet. With resource identification, NEA proposes construction of a 25 MW geothermal plant Pilot Point Community Energy Plan October 2008 77 serving 25+ villages within the Bristol Bay and Lake Regions. This project would be the first utility-grade geothermal development in Alaska. The initial cost estimate for the plant and approximately 450 miles of transmission line interconnecting regional villages is $200 million. Over the past decade NEA has invested approximately $1 million in initial research and exploration of renewable alternative energy and is committed to being a financial partner as the project proceeds. NEA is approaching both state and federal governments for matching assistance. Proposed Project: 25 MW Geothermal Generation Facility 450 miles of transmission lines to bring electric energy to 25+ villages. Lines would extend from Naknek/King Salmon to Pilot Point; to Iliamna/Port Alsworth; and to Dillingham/New Stuyahok/Togiak and beyond Initial Load: 18 MW with full potential to use 25 MW within two years Benefits: Dramatic drop in the cost of power production, estimated to decrease 70% Cleaner environment with elimination of 3.5 million gallons of diesel fuel now used to generate electricity An energy base for long-term economic development sustaining local communities While NEA’s interest in the project focuses on production of electricity, identification of a geothermal resource could bring many other benefits, including hydrogen productio n, hot water heating to nearby communities, and the development of spas, greenhouse projects, and other related businesses. Pilot Point Community Energy Plan October 2008 78 Pilot Point Community Energy Plan October 2008 79 Tidal Energy There are two tidal energy projects in the State that are relevant to Pilot Point. One is the experimental unit in place in Nushagak Bay by the University of Alaska in Dillingham and the other, a large project is at the Knik Arm crossing. Both projects will have to overcome the barriers of mud/silt displacement, large salmon migration migrations and very strong currents combined with large tides all conditions that Ugashik Bay has. Tidal energy in the future may be very promising for the intertidal river/bay systems in Bristol Bay. What is tidal energy? Tidal energy is one of the oldest forms of energy used by humans. Indeed, tide mills, in use on the Spanish, French and British coasts, date back to 787 A.D.. Tide mills consisted of a storage pond, filled by the incoming (flood) tide through a sluice a nd emptied during the outgoing (ebb) tide through a water wheel. The tides turned waterwheels, producing mechanical power to mill grain. We even have one remaining in New York- which worked well into the 20th century. Tidal power is non-polluting, reliable and predictable. Tidal barrages, undersea tidal turbines - like wind turbines but driven by the sea - and a variety of machines harnessing undersea currents are under development. Unlike wind and waves, tidal currents are entirely predictable. Tidal energy can be exploited in two ways: * By building semi-permeable barrages across estuaries with a high tidal range. * By harnessing offshore tidal streams. Barrages allow tidal waters to fill an estuary via sluices and to empty through turbines. Tidal streams can be harnessed usin g offshore underwater devices similar to wind turbines. Pilot Point Community Energy Plan October 2008 80 Most modern tidal concepts employ a dam approach with hydraulic turbines. A drawback of tidal power is its low capacity facto r, and it misses peak demand times because of 12.5 hr cycle of the tides. The total world potential for ocean tidal power has been estimated at 64,000 MWe. The 25-30 ft tidal variations of Passamaquoddy Bay (Bay of Fundy) have the potential of between 800 to 14,000 MWe. Where are good areas for exploiting tidal energy? Tidal range may vary over a wide range (4.5-12.4 m) from site to site. A tidal range of at least 7 m is required for economical operation and for sufficient head of water for the turbines. Hammerfest Traditional tidal electricity generation involves the construction of a barrage across an estuary to blo ck the incoming and outgoing tide. The dam includes a sluice that is opened to allow the tide to flow into the basin; the sluice is then closed, and as th e sea level drops, the head of water (elevated water in the basin) using traditional hydropower techno logy, drives turbines to generate electricity. Barrages can be designed to generate electricity on the ebb side, or flood side, or both. Tidal range may vary over a wide range (4.5-12.4 m) from site to site. A tidal range of at least 7 m is required for e conomical operation and for sufficient head of water for the turbines. A 240 MW facility has operated in France since 1966, 20 MW in Canada since 1984, and a number of stations in China since 1977, totaling 5 MW. Tidal energy schemes are characterized by low capacity factors, usually in the range of 20-35%. The waters off the Pacific Northwest are ideal for tapping into an ocean of power using newly developed undersea turbines. The tides along the Northwest coast fluctuate dramatically, as much as 12 feet a day. The coasts of Alaska, British Columbia and Washington, in particular, have exceptional energy-producing potential. On the Atlantic seaboard, Maine is also an excellent candidate. The undersea environment is hostile so the machinery will have to be r obust. Pilot Point Community Energy Plan October 2008 81 Currently, although the technology required to harness tidal energy is well established, tidal power is expensive, and there is only one major tidal generating station in operation. This is a 240 megawatt (1 megawatt = 1 MW = 1 million watts) at th e mouth of the La Rance river estuary on the northern coast of France (a large coal or nuclear power plant generates about 1,000 MW of electricity). The La Rance generating station has been in operation since 1966 and has been a very reliable source of ele ctricity for France. La Rance was supposed to be one of many tidal power plants in France, until their nuclear program was greatly expande d in the late 1960's. Elsewhere there is a 20 MW experimental facility at Annapolis Royal in Nova Scotia, and a 0.4 MW tidal power plant near Murmansk in Russia. UK has several proposals underway. Studies have been undertaken to examine the potential of several other tidal power sites worldwide. It has been estimated tha t a barrage across the Severn River in western England could supply as much as 10% of the country's electricity needs (12 GW). Similarly, several sites in the Bay of Fundy, Cook Inlet in Alaska, and the White Sea in Russia have been found to have the p otential to generate large amounts of electricity. What is the impact on the environment? Tidal energy is a renewable source of electricity which does not result in the emission of gases responsible for global warmi ng or acid rain associated with fossil fuel generated electricity. Use of tidal energy could a lso decrease the need for nuclear power, with its associated radiation risks. Changing tidal flows by damming a bay or estuary could, however, result in negative impacts on aq uatic and shoreline ecosystems, as well as navigation and recreation. The few studies that have been undertaken to date to identify the environmental impacts of a tidal power scheme have determined that each specific site is different and the impacts depend greatly upon local geography. Local tides changed only slightly d ue to the La Rance barrage, and the environmental impact has been negligible, but this may not be the case for all other sites. It has been estimated that in the Bay of Fundy, tidal power plants could decrease local tides by 15 cm. This does not seem like much when one considers that natural variations such as winds can change the level of the tides by several metres. Pilot Point Community Energy Plan October 2008 82 What are the costs of tidal energy? Tidal power is a form of low-head hydroelectricity and uses familiar low-head hydroelectric generating equipment, such as has been in use for more than 120 years. The technology required for tidal power is well developed, and the main barrier to increased use of the tides is that of construction costs. There is a high capital cost for a tidal energy project, with possibl y a 10-year construction period. Therefore, the electricity cost is very sensitive to the discount rate. The major factors in determining the cost effectiveness of a tidal power site are the size (length and height) of the barrage required, and the difference in height between high and low tide. These factors can be expressed in what is called a site's "Gibrat" ratio. The Gibrat ratio is the ratio of the length of the barrage in metres to the annual energy production in kilowatt hours (1 kilowat t hour = 1 KWH = 1000 watts used for 1 hour). The smaller the Gibrat site ratio, the more desireable the site. Examples of Gibrat ratios are La Rance at 0.36, Severn at 0.87 and Passamaquoddy in the Bay of Fundy at 0.92. Offshore tidal power generators use familiar and reliable low-head hydroelectric generating equipment, conventional marine construction techniques, and standard power transmission methods. The placement of the impoundment offshore, rather than usin g the conventional "barrage" approach, eliminates environmental and economic problems that have prevented the deployment of commercial-scale tidal power plants. Three projects (Swansea Bay 30 MW, Fifoots Point 30 MW, and North Wales 432 MW) are in development in Wales where tidal ranges are high, renewable source power is a strong public policy priority , and the electricity marketplace gives it a competitive edge. Q. What are some of the devices for tidal energy conversion? The technology required to convert tidal energy into elect ricity is very similar to the technology used in traditional hydroelectric power plants. The first requirement is a dam or "barrage" across a tidal bay or estuary. Building dams is an expensive process. Therefore, the best tidal sites are those where a bay has a narr ow opening, thus reducing the length of dam which is required. At certain points along the dam, gates and turbines are installed. When there is an adequate difference in the elevation of the water on the different sides of the barrage, the gates are opened. Th is "hydrostatic head" that is created, causes water to flow through the turbines, turning an electric generator to produce electricity. Pilot Point Community Energy Plan October 2008 83 Electricity can be generated by water flowing both into and out of a bay. As there are two high and two low tides each day, e lectrical generation from tidal power plants is characterized by periods of maximum generation every twelve hours, with no electricity generation at the six hour mark in between. Alternatively, the turbines can be used as pumps to pump extra water into the bas in behind the barrage during periods of low electricity demand. This water can then be released when demand on the system its greatest, thus allowing the tidal plant to function with some of the characteristics of a "pumped storage" hydroelectric faci lity. What are some of the devices for tidal energy conversion? The technology required to convert tidal energy into electricity is very similar to the technology used in traditional hydroe lectric power plants. The first requirement is a dam or "barrage" across a tidal bay or estuary. Building dams is an expensive process. Therefore, the best tidal sites are those where a bay has a narrow opening, thus reducing the length of dam which is required . At certain points along the dam, gates and turbines are installed. When there is an adequate difference in the elevation of the water on the different sides of the barrage, the gates are opened. This "hydrostatic head" that is created, causes water to flow throu gh the turbines, turning an electric generator to produce electricity. Electricity can be generated by water flowing both into and out of a bay. As there are two high and two low tides each day, e lectrical generation from tidal power plants is characterized by periods of maximum generation every twelve hours, with no electricity generation at the six hour mark in between. Alternatively, the turbines can be used as pumps to pump extra water into the bas in behind the barrage during periods of low electricity demand. This water can then be released when demand on the sys tem its greatest, thus allowing the tidal plant to function with some of the characteristics of a "pumped storage" hydroelectric faci lity. Why tidal energy? The demand for electricity on an electrical grid varies with the time of day. The supply of elect ricity from a tidal power plant will never match the demand on a system. But, due to the lunar cycle and gravity, tidal currents, although variable, are reliable and predictable and their power can make a valuable contribution to an electrical system which has a variety of sources. Tidal electricity Pilot Point Community Energy Plan October 2008 84 can be used to displace electricity which would otherwise be generated by fossil fuel (coal, oil, natural gas) fired power pl ants, thus reducing emissions of greenhouse and acid gasses. Oil & Gas There is one promising discovery resulting from the drilling explorations of the 1960’s and 1970’s located at Ugashik One approx. 6 air miles across the river from Pilot Point. Potential resource estimates are as high as 5,000 barrels of oil per day and 5,000 cubic feet of gas. Bristo Bay Native Corporation owns the subsurface rights and Pilot Point Native Corporation the surface. Pilot Point Community Energy Plan October 2008 85 The potential for a small energy company to develop the site could provide energy for much of the coastal western Alaska. Pilot Point Community Energy Plan October 2008 86 Pilot Point Community Energy Plan October 2008 87