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HomeMy WebLinkAboutBristol Bay Regional Power Plan Wind Energy Analysis 1982BRI 033 Alaska Power Authority LIBRARY COPY Bristol Bay Regional Power Plan WIND ENERGY ANALYSIS FINAL REPORT PREPARED BY WIND SYSTEMS ENGINEERING, INC. Bristol Bay Regional Power Plan WIND ENERGY ANALYSIS FINAL REPORT FEBRUARY, 1982 PREPARED UNDER CONTRACT FOR STONE & WEBSTER ENGINEERING CORPORATION FOR THE ALASKA POWER AUTHORITY BY WIND SYSTEMS ENGINEERING, INC. 1551 EAST TUDOR RD., ANCHORAGE, ALASKA 99607 Mark Newell, Editor TABLE OF OF CONTENTS Section One: Wind Resource Assessment 1.1 Power in the Wind. .. . 1.2 Battelle Assessment .. . 1.3. The Wind Resource... . 1.4 Data Availability . .. . Section Two: Site Identification 2.1 Introduction =o 6-6. « Coastal ‘Sites . . .« « -« Naknek to Bruin Bay Corridor Inland Areas emis ie 2.5. Conelusions . . «. e« -« .« Section Three: Wind Generation Equipment 3.1 Introduction cjitie|jiejj« 3.2.-Wind Turbine Size . .« «:.% Sw3 « ARES Of Rotation . «s.%* .« Generator Type lie het] te Wind Generator Controls. . 3.6 Conclusions and Recommendations Section Four: Storage, Monitoring & Systems Integration 4.1 Introduction Sere S eee c re 4.2 Storage Apparatus. .. . 4.3 Monitoring Equipment. . . 4.4 Systems Integration . . . 4.5 Conclusions and Recommendations oO fF WN 18 21 25 27 14 17 Section Five: Power Production Analysis Introduction -. » » +» s* « ‘e. « Methodology we le ed eae | et 5.3 ‘Power, Production. . . « +» ».» .e« « 5.4 Conclusions & Recommendations. . . Section Six: Restraints Identification 6.1 Assessment of Probable Environmental Tnpacesei\<\{ j- jfsl) elie) iiel| e«Lielt ts 6.2 Regulatory Restraints a] fe] |] leis 6.3 Regional Restraints . . . .« «© . 6.4 Conclusions and Recommendations . . Section Seven: Facility Schedule 7.1 Introduction ol] fo) Elf ie. Tell) aly fel lite 7.2 Commercial Availability. . .. . qed Facility Schequle . « «s+ « » le la Section Eight: Economic Analysis instal Lea] Coste 6. s.saoe- = 6 ste et 8 Power Production Cost Comparison 8.3 Conclusions and Recommendations . . Appendix A: Wind Data Appendix B: Bristol Bay Wind Generators Bibliography 12 12 13 1 a WIND RESOURCE ASSESSMENT The Bristol Bay area shows a very “strong. wind: nes.60'rce availability. The available data is however very sparse and poor in quality. Maps were developed from the extrapolated data showing the wind power density for the region and a certainty rating was given to each quarter section. The available data indicates the resource is strong enough to.justify an indepth monitoring program to accurately quantify it for specific locations. @ 1.1 Power inthe Wind Traditionally the area of distribution of the wind resource has been described by isopliths of wind speed. However, in defining the wind resource for use in estimating the potential output from wind machines, a more useful measure is wind power density, or the power per unit of cross- sectional area of the wind stream. The power in the wind can be derived from classic momentum theory where P represents power, m is the mass in the moving air, and V is the velocity or speed of the wind. Therefore: P=1/2 m v2 Mass is described by air density (p), the area through which the wind passes (A), and its speed (V). m= p AV Substituting into the equation for Power P = 1/2 p av? P= 1/2 p v3 Where k equals the power density. This derivation illustrates the important influence of wind speed. Power is a cubic function of wind speed. A doubling of wind speed increases wind power eight times. Slight changes in wind speed produce a corresponding large change in power. For example, increasing wind speed one mph @ produces a 30% increase in the power available. 1.2 Battelle Assessment Battelle Pacific Northwest Laboratories contracted the Arctic Environmental Information and Data Center (AEIDC) at the University of Alaska to describe the data available on the Alaska wind resource and to map the state's wind power potential. The results of the work for the Bristol Bay area are presented in Figure 1.1 and 1.2 (attached). Note that the map presents wind power in the form of wind power classes. Each class represents the range of wind power likely to be found at well exposed sites. These classes are approximations of the areal distribution of wind power and the demarcation between them should not be construed to represent definite boundaries. Where the data was available, power density was based on the mean temperature, mean pressure (p), and elevation at the station where the wind data was recorded. Because frictional effects of obstructions at the surface retard wind flow near the ground, anemometer height during the period of record was also taken into account. Wind power was adjusted to the 10 meter and 50 meter heights using the 1/7 power law: Ye a (Hg) 1/7 That is, the increase in wind speed with height above the ground is the ratio of the new height (H) to the original height (Ho) raised to the 1/7 power. This is a conservative estimate of the increase in wind speed with height. FIG. 1:1 NONDALTON ILIAMNA —_— —_— HALEN® —_ NEW > CU a“ IGIUGIG OLIGANEK® “ars /* 5 f RAY NEW STUYHOK®e@ | EKWOK® LEKNAGIK 9 od w Aes I DILLINGHAM | PLATINUM EGEGIK WIND POWER DENSITY WATTS/M2 WIND POWER CLASS BRISTOL BAY STUDY AREA PORT HEIDEN . | 6 ] y ANAL NONDALTON ILIAMNA NEWHALEN e KOLIGANEK BRUIN BAY @LEVELOCK PLATINUM Ofna CLARKS PT. KUK CAPE = NEWENHAM —_— EGEGIK WIND DATA CERTAINTY [__]tow-inteRmepiaTe DEGREE Little or no data exists in or near the cell, but the smal] variability of the resource and the low complexity of the terrain suggest that the wind resource will not differ substantially from the resource in nearby areas with data. ORT HEIDEN There iS limited wind data in the vicinity of the cell, but the low complexity of terrain and the small mesoscale variability of the resource indicate little departure from the wind resource in nearby areas with data. Where data was not summarized into a wind speed frequency distribution, AEIDC assumed a Weibull distribution of wind speeds where: (Fy) = 1.07 3 v3 In these cases, the average annual wind speed and monthly average wind speeds were found by examining only one year of data. This limited sample coupled with use of the Weibull distribution could greatly underestimate the power in the wind. In mountainous areas the estimates are based on the correlation between mountaintop wind speeds and free air wind speeds. AEIDC extrapolated upper air data to lower elevations, e.g., mountain crests-from the mean scaler wind and use of a Rayleigh wind speed distribution to produce a power estimate. To account for frictional effects near the surface, this extrapolated free-air wind speed was reduced by two-thirds for power at 10 meters, and one-third for power at 50 meters. The power classes of Figure 1.1 depend upon the subjective integration of several factors: quantitative wind data, qualitative indicators of wind speed or power, the character of exposed sites in various terrain, and familiarity with mesoscale as well as microscale meteorlogical conditions, climatology and topography. Therefore, the abundance and quality of the data, the complexity of terrain; and the geographical variability of the resource together determine the degree of certainty that can be placed on the power classes shown on Figure l.l. The Certainty Rating ranges from a low of one to a high of four. Figure 1.2 illustrates the certainty rating ascribed to the Bristol Bay region. Much of the study area has a low to intermediate degree of certainty because: - little or no data exists, but there is little variability in the wind resource and the terrain is simple, or - limited data exists, but the terrain is highly complex or the mesoscale variability of the wind resource is large. There is little data available over much of the study area; fortunately though, the terrain within the central portion (Dillingham - Koliganek - Naknek - Newhalen) is not complex, as it is composed of a large lowland plain. 1.3 The Wind Resource The few recording stations within the study area required that AEIDC infer much of the wind resource from qualitative indicators of wind power. The most widely used technique depends on certain combinations of topographical and meteorological conditions; one of which is a gap or pass in areas of frequent strong pressure gradients. Another geographic feature suited to a good wind resource is a large plain or valley with persistent strong downslope winds associated with strong pressure gradients. Both features are found in a broad corridor from Naknek to Iliamna Lake to Kamishak Bay. Based on limited data from King Salmon, Iliamna and Bruin Bay this corridor varies from a class 4 to 5 in the west to a class 7 in the east. One year of unsummarized data from Bruin Bay produced an annual average wind power of over 1300 watts/m-. The western coastal areas around Cape Newenham and Platinum show a very strong resource which is most likely indicative of the Nushagak Peninsula. Similarly, the western coastal sites along the Alaskan Peninsula of Port Heiden and Pilot Point produced a power class from 5 to 7 which is supportive of a good resource in Egegik. Eastern coastal sites along the Kamishak Bay also have good potential with the Shelikof Strait ranging from 5 to 6. Inland sites north of Dillingham and Iliamna Lake are less promising in comparison to coastal sites and those along the Naknek-Bruin Bay corridor. Data from 9 stations in the Bristol Bay study area is available as shown below. Data from five stations is in digitized and summarized form. Three stations have only summarized data, and there is one station with only unsummarized data. WIND DATA AVAILABLE FOR BRISTOL BAY REGION 1) Bruin Bay-unsummarized data 2) Cape Newenham-digitized & summarized data 3) Dillingham-summarized data 4) Iliamna-digitized & summarized data 5) King Salmon-digitized & summarized data 6) Pilot Point-digitized & summarized data 7) Port Heiden-digitized & summarized data 8) Platinum-summarized data 9) Tanaliam Point-summarized data The following describes the terrain surrounding the recording station at Cape Newenham at the extreme western end of the study area, at Iliamna near the center of the study area, and at King Salmon in the south-central portion of the study area. FIGURE 1.4 SITE DESCRIPTION Cape Newenham Cape Newenham is on a rugged point of land at the northwest end of Bristol Bay. It is sheltered on the east, south and west by a ridge that extends to more than 610 m. It is open to the northwest, and there is a saddleback in the ridge to the southeast. The terrain slopes steeply upward toward the southeast in the vicinity of the station. During the nine-year period of record used in the summary, there was an average of 22 observations per day. Lliamna Iliamna is located near the north shore of Iliamna Lake along the Newhalen River, which connects Lake Clark to Iliamna Lake. The area immediately surrounding the station is relatively level and covered with muskeg, and slopes gently southward to the lake. To the northeast and northwest on both sides of the Newhallen River there are peaks over 600 m within 15 km of the station. This station is exposed to winds from Cook Inlet across the lake from the east-southeast and also from the north from the direction of Lake Clark. During the 16-year summary used in this analysis there were 24 observations per day. King Salmon King Salmon is located about half a kilometer (one-fourth mile) from the Naknek River, 29 km inland from the shores of Kvichak Bay at the east end of Bristol Bay. The terrain surrounding the station is gently rolling, barren tundra for 50 to 100 km in the north through east to south-southwest. Some 100 km to the east are the mountains of the Aleutian Range with peaks to more than 2,260 m. During the summary period used in this analysis, there were eight observations per day digitized. 1.4 Data Availability In Appendix A is a listing in tabular form of the wind speed and power data from eight of the stations within the project area. Where possible, the average annual wind speed is given at the anemometer height. For the three stations used in the AEIDC assessment, the average wind speeds are extrapolated to a height of 10 meters and 50 meters based on the anemometer history. AEIDC also calculated the annual average wind power available at the anemometer's height, at 10 meters, and at 50 meters, using the distribution of wind speeds recorded at the site. The annual average wind speed at two additional stations was found, but was not extrapolated to 10 meters nor 50 meters because the history of the anemometer is unknown. Similarly, the wind summaries (frequency distributions) for seven stations were not used to calculate power density in the accompanying table. The certainty of the resources over most of the project area is low, with a Certainty Rating of 2 as a result of the lack of data. There are only a few cells over the project area with a rating of 3. These cells lie over data points such as Platinum, Dillingham, King Salmon, Pilot Point and Port Heiden. 10 There is a need to confirm the resource along the Naknek - Bruin Bay corridor. Additional data from several stations along this corridor would define a resource that could fit neatly into a power generator scheme for the Dillingham, Naknek, and Iliamna areas. The existing one year unsummarized data for Bruin Bay is insufficient to characterize the resource. This is particularly important when considering a resource of this apparent magnitude. Because of the seasonal variations in the wind resource and seasonal power needs for this area, a correlation needs to be drawn between wind power availability and demand for energy. The type of data needed for this level of analysis would require a microprocessor-based data collection system. At this writing, the Alaska Power Administration has let a contract to collect data in the King Salmon area to determine prospects for wind farming. This information should be integrated into a master plan as soon as it is available. 11 2. SITE IDENTIFICATION The Bristol Bay reyion in general shows a very high wind power density. This conclusion is based, however, on a limited number of data points that have a low degree of certainty associated with them. Site selection is therefore based considerably on subjective judgement, and this should be kept in mind. The King Salmon area shows the best potential for current development with Egegik having an equally strong resource. The presence of a fair number of windgenerators in the Bristol Bay area (see Appendix B) helps substantiate the wind power availability. 2.1 Introduction Using the wind data found in Appendix A and extrapolating to the study villages, the parameter wind power density is used to compare the attractiveness of each site. The wind power density is expressed in watts of power available in the wind per square meter of blade area intersecting it. The following table is a standard classification for wind sites: TABLE 2.1 CLASSES OF WIND POWER DENSITY 10 m (33 ft) 50 m (164 ft) Wind Wind Power Wind Power Power Density Speed Density Speed Class watt/m2 mph watts/m2 mph 1 100 9.8 200 12.5 2 150 11.5 300 14.3 ? 200 12.5 400 15.7 4 250 13.4 500 16.8 $s 300 14.3 600 17.9 6 400 15.7 800 19.7 7 1000 21.1 2000 26.6 2.2 Coastal Sites A very strong resource is indicated along the entire Bristol Bay coastline with the best sites being Egegik and King Salmon (Wind Power Class 5). Naknek & South Naknek (Class 4 ) are good second choices with Ekuk, Clarks Point, Levelock, Portage Creek and Manokotak (Class 3) also showing a coastal influence. On the Shelikof Strait side of the Peninsula, Kamishak Bay (Class 7) exhibits a resource which, if proven to be persistent, could supply power for a major part of the region. Dillingham (Class 2) has some coastal influence but would require more data to be a strong contender. King Salmon has some of the best recorded wind data to work from, with the winter months providing the most consistent winds. From November to March the diurnal variation is almost imperceptible, yet during the summer months the variance is a maximum of only about two miles per hour from the average. King Salmon, being typical of the coastal sites, shows a fairly reliable wind resource from year to year with very directional winds. 2.3 Naknek to Bruin Bay Corridor There is data to support the existence of a wind corridor from Kamishak Bay through Lake Iliamna following the Kvichak River valley out to the Bay. This corridor yields a good resource at Igiugig (Class 4). The winds through this corridor are not as consistent as the coastal winds. They exhibit a seasonal characteristic with the low wind month being July. Even though Iliamna and Nondalton show a low wind power (class 2) this does not mean there isn't much wind there. On the contrary, the area is known for high wind storms; however, the gusty storms do not make for optimal wind turbine performance. The presence of several windgenerator systems (see photos-Appendix B) in the corridor testifies more to the high cost of diesel fuel and the desire for independence than to a wind resource strong enough for utility consideration. Additionally, none of the windgenerator owners had documented with a recording anemometer the winds at their sites, nor was any data on kilowatt-hours produced during a finite time period available. Working backwards from fuel savings on the diesel generator set/battery/windgenerator systems does show a wind resource substantial enough to make the windgenerator competitive (generally considered to be 12 mph annual average). 2.4 Inland Areas Villages which show a doubtful potential are located away from the corridor and further inland. These villages are: Aleknagik, Ekwok, New Skuyahok, and Koliganek (Class 2). There is however very little data to support this assumption. Dillingham is located in a class 2 zone, yet the winds on the waterfront are typically higher than the winds at the airport (where the anemometer is ). Windmill Hill in Dillingham got its' name from the water-pumper windmills which operated there in the pre-Nushagak Electric Association days. There have been several wind chargers in the city and outskirts (see photo in Appendix B ) as well as a battery charging unit on top of Juant Mountain for the television repeater station (see correspondence in Appendix B). Again, there is not any monitoring of winds or power output from these machines, but there is reason to believe that the resource is present and dependent on localized climatology and terrain. It is also important to consider the channeling effect of mountain passes which could considerably enhance the power available in the inland areas. Such site specific wind information does not exist in this region, and as such leaves open the possibility that as transmission line routes are chosen, very windy terrain could be crossed. This is especially true when the consideration of routes excludes the lowlands and the lines are confined to the high exposed ground. 2.5 Conclusion Before an area can be further screened for wind power potential, the local terrain must be considered. Additionally, land use, ownership, proximity to end use, and soil conditions would need investigtion. Using the available data as a basis for ranking of candidate sites for development of a utility scale program, the following table is presented: TABLE 2.2 WIND POWER POTENTIAL RANKING Site Wind Power Class eer 1) Bruin Bay 2) King Salmon 3) Egegik 4) Naknek + South Naknek 5) Igiugig 6) Levelock Newhallen Portage Creek Clark's Point 7) Manokotak 8) Dillingham 9) Iliamna 10) Nondalton 11) Aleknagik Ekwok 12) Koliganek wv Bw NY KY KY KY WwW WwW WwW WwW WwW fF F&F UN WN A 2.5.1 Best Sites for Current Development From the preceeding table, Bruin Bay can be eliminated because of its distance from population centers and lack of long term data to confirm the resource. King Salmon and Egegik thus appear to be the best sites for a wind turbine array based on the available information. 2.5.2 Best Sites for Future Development The Naknek/South Naknek area as well as Igiugig would be logical choices for future wind-farming possibilities. Of the two, the Naknek resource is more conducive to wind machine survival, being under a steadier and more consistent coastal influence. 3. WIND GENERATION EQUIPMENT For purposes of this study; windgenerators have been classified in three different ways: turbine diameter (size), axis of rotation and type of generator. The first grouping by size defines small, medium, and large turbines, with the smaller machines being the most commercially available and tested. Vertical versus horizontal axis turbines are discussed with key advantages and drawbacks being pointed out. Four different types of generation are presented: induction- type units being most common, synchronous generators being found on larger units, and synchronous and asynchronous inverters associated with direct-current generators. Typical controls found on most turbines are treated generically; with the cone lus6di Ons and recommendations on generator types and configurations for Bristol Bay completing the section. 3.1 Introduction There are approximately 50 manufacturers of windgenerators in the United States today and an equal number overseas. These machines range from experimental first generation units to well-proven production models with several years of operating experience. Considering the wide variability in size, configuration and output characteristics, there is a need to use a methodology that reduces these variables to a single parameter that reflects potential output capability. This parameter is rotor swept area. The amount of energy intercepted by a wind turbine and converted to useable energy is primarily dependent upon swept area; that is, the area of the windstream intercepted by the wind turbine. Once the swept area is defined, potential output can be calculated by assuming an overall operating efficiency representative of today's high speed wind turbines. In equation form: k x A x % cfficiency = Mean Power Output where the power density (&) is found from AEIDC's resource assessment, and (A) is the swept area. Mean Power Output (MPO) is a measure of the average power output of the turbine independent of the generator size. The Mean Power Output can be used to produce an average energy output over any time period. The most often used is Annual Energy Output, which describes the average amount of energy a wind turbine will annually produce. Example: A conventional wind turbine uses a rotor 10 meters in diameter and is to be sited near King Salmon where the power density is 200 w/m2 at a 10 meter height. Solution: The swept area of a conventional wind turbine is found from the area of the circle swept by the rotor. 200 ¥/m2 x 80 n2 x 25% = Mean Power Output 4,000 W = 4kW = If we wanted the Annual Energy Output we only need to include the number of hours we expect the turbine to operate annually. MPO x 7,000 hrs/yr = AEO 4 kW x 7,000 hrs/yr = 28,000 kWh/yr. As mentioned previously, wind speed and, hence, power increases with height above the ground. (The wind power map shown in Figure 1.1) is based on the wind power at 10 meters above the ground. Wind turbines will normally be erected on towers greater that 10 meters in height. Most small machines will use 60 foot towers at a minumum. Consequently, it will be necessary to increase the MPO or Annual Energy Output estimates to incorporate the increased power available at 60 or more feet above the ground. BP _ (H 10.43 Po Ho This formula will be used to extrapolate the available wind power to various tower heights. (as shown in the following table). TABLE 3.1 WIND POWER AT NOMINAL TOWER HEIGHTS Power Class Power 60° ft. 80 ft. 200 ft. W/m? 1 100 130 150 220 2 150 195 220 330 3 200 260 300 440 4 250 325 370 545 § 300 390 _» *440 655 6 450 580 660 980 a 1,000 1,300 1,500 2,180 —_— 3.2 Wind Turbine Size Reflecting conventional power plant design, wind generators have commonly been referred to by the size of their generators. Because wind speed varies widely, it is necessary to also define a wind speed at which the wind turbine's generator reaches its rated capacity. There is no standard rated wind speed and, as a result, generator size is a poor indicator of either the Mean Power Output or the Annual Energy Output. The methodology chosen for this analysis uses rotor diameter to define machine size. The following table illustrates some comparison between rotor diameter, kW capacity, and machine size. TABLE 3.2 NOMINAL kW CAPACITIES FOR ROTOR DIAMETERS KW Capacity* Rotor Diameter Small 0-50 0-15 meters Medium 50-1000 25-75 meters Large 1000-5000 75+ meters *Rated at 30 mph 3.2.1 Small Machines All wind turbines installed in Alaska to date have been from the small machine class. They can be broken down further into categories based on use. TABLE 3.3 SMALL TURBINE kW CAPACITIES KW Capacity* Rotor Diameter Cabin Size 0-1 2 - 3 meter Homestead Size 1-=.10 3 - 10 meter Village Size 10 - 50 10 - 15 meter *Rated at 30 mph Wind generators in these sizes are the most readily available and are the most commercially developed. 2000 8 POWER OUT (watts) WIND SPEED(mph) 4 Meter Turbine GENERATOR TYPE & INTERFACE MODE This unit uses a 115 VAC brushless induction gener- ator for direct utility intertie. ; CONTROLS The unit requires a utility derived reference to: 1. Operate. 2. Develop a 60 hz output. A tower mounted anemometer is used to monitor wind velocity and control the operating modes. Cut-in is at 10 mph, cut-out at 40 mph. OPERATION/ SAFETY The unit will not operate unless a utility reference is present. If utility power is lost, the unit disconnects from the utility line and an electro-hydraulic brake is applied, stopping the rotor. Emergency stop due toa power train failure is performed by the automatic deployment of spring loaded centrifugally actuated ro- tor tip-flaps. 6 Meter Turbine GENERATOR TYPE & INTERFACE MODE A 230 VAC, 60 hz induction motor/generator is used to provide a direct utility intertie. CONTROLS The unit requires a utility derived reference to: 1. ‘Operate. 2. Develop a 60 hz output. A tower-mounted anemometer is used to monitor wind velocity and control the operating modes (cut-in at 8.5, cut-out at 45 mph). OPERATION/ SAFETY The unit will not operate: 1. .Untess .thepzjutgility reference is present Or, 2. When windspeed is less Chan, .6@.5 .° mphs or greater than 45 mph. If utility power is lost, the unit disconnects from the grid and an electro- hydraulic brake is engaged. Emergency stop due to over speed (or brake engage- ment) is performed by the automatic deployment of rotor tip brakes (aerody- namic). The deployment of the tip brakes is also enabled by a power-train failure. Sy IOC SC DCT \ —S SSS POWER OUTPUT (kW) oO 10 20 30 40 50 WIND SPEED (mph) 7 Meter Turbine GENERATOR TYPE & INTERFACE MODE Power is developed by a 3- Phase alternator whose output is rectified and processed by a synchronous inverter. The output is in the form of "pulses" of energy timed to occur within the sine wave enve- lope. A "leading" power factor is claimed for the “synchronous unit. CONTROLS The centrifugally operated wah I) governor at the propeller if | i l] hub maintains rpm rates under normal conditions. The alternator output is controlled through its field windings whose exci- tation is monitored and adjusted by the synchro- nous inverter circuitry. High winds are overcome through the use of an offset tail-vane that turns the rotor out of the wind. OPERATION/ SAFETY The synchronous inverter will disengage itself from the utility should: 1. The windgenerator's output drop below pre- set limits or, 2... The utility -line fails. POWER OUTPUT (kW) The unit also has a manu- ally engaged friction brake for routine service 0 . 10 15 20 25 or emergency shutdown. WIND SPEED (mph) @ 10 Meter Turbine GENERATOR TYPE & INTERFACE MODE This unit utilizes an induction motor/generator to provide 440/220VAC 1-3 phase power directly to the utility. CONTROLS Rotor rpm is maintained by the aerodynamic/mechanical properties of the rotor design. The blades automa- tically stall in high winds to prevent overloading of the generator. OPERATION/ SAFETY The unit has withstood winds in excess of 85 mph and specifications claim that it will operate at windspeeds of 100 mph. A unique tower design allows the entire unit to be "tilted" providing ground level maintenance on the windgenerator. POWER OUTPUT (kW) . | ei, ace : 7 Wet YUL Veer | YO POWER PROFILE 40 Cut-in Rated Cut-Out} 9 30 20 10 oO 0 5 10 15 20 25 30 35 WIND SPEED (mph) 3.2.2 Medium Machines No units in this size range have been installed in Alaska. Several units have been installed in the lower 48 and in Canada. There are only a handful of manufactures presently building machines of this size and none are in mass production. However, a considerable number of hours have been logged on these machines and data on reliability and performance is available through the Department of Energy's MOD-OA program and tests done by WTG systems. TABLE 3.4 MEDIUM TURBINE CAPACITIES Manufacturer KW Capacity* Rotor Diameter WTG Systems 200 25 meter DAF 230 37 x 24 meter Alcoa 300-500 38 x 27 meter Westinghouse 200 38 meter Voland 250 28 meter *Rated at 30 mph 10 16.5 Meter Turbine @ GENERATOR TYPE & INTERFACE MODE Induction 240/480 3-phase vA 60 hz. pas NY a CONTROLS é N A aX | N/A $ a OPERATION/ SAFETY ay M N/A NX x 0 11 24.4 Meter Turbine GENERATOR TYPE & INTERFACE MODE This model uses an induc- tion generator of 55 KW capacity delivering 3- phase power at 480 VAC/60 hz. The interface is direct utility intertie. CONTROLS An anemometer monitoring average windspeed deter- mines the cut-in and cut- out conditions. OPERATION/ SAFETY The system is operated hydraulically and requires utility power to begin operation. A centrifugally operated switch on the rotor shaft will cause a loss of hydraulic pressure, shutting down the system and applying the brake. 50 3g a ° POWER OUTPUT (kW) o.lU8 ° 12 POWER PROFILE ° 5 10 15 20 25 WIND SPEED (mph) 30 35 6440 24.5 Meter Turbine GENERATOR TYPE & INTERFACE MODE This unit has a 200 KW (continuous rated) syn- chronous generator pro- viding power at 240/480 VAC 60 hz. The system is designed to operate either as a utility intertie or as a stand alone source of utility grade power. CONTROLS The unit utilizes a micro- processor based system for control and also provides data collection and acqui- sition as well as remote control and status display functions. OPERATION/ SAFETY The microprocessor will allow the windgenerator to come up to synchronous speed and compares its output with the utility reference. When they are within 1% the main contactor is enabled. The relationship between wind- generator output and utility power is contin- uously monitored and synchronization is main- tained by adjusting the rotor tip flaps and/or Phasing in auxiliary "dummy" loads. POWER OUTPUT (kW) 13 15 20 256 WIND SPEED (mph) 30 35 28 Meter Turbine | GENERATOR TYPE & INTERFACE MODE This unit has two asyn- chronous generators rated at 265 and 58 KW that pro- duce power at 480 VAC, 50/60hz. The unit is designed for direct util- ity intertie. CONTROLS N/A OPERATION/ SAFETY The blade pitch is used to maintain synchronous speed as well as for emergency overspeed shutdown. The smaller capacity gen- erator operates at low wind speeds while the larger unit comes on-line during periods of higher winds. POWER OUTPUT (kW) WIND SPEED (mph) 14 38 Meter Turbine GENERATOR TYPE & INTERFACE MODE This unit uses either induction or synchronous generators rated at 560 and 625 KVA respectively. The output is at a voltage of 4160 VAC, 3-phase 60hz. This unit is designed for direct utility interface. CONTROLS System operation is con- trolled via a micropro- cessor that constantly monitors all operating parameters and maintains rotor rpm, synchroniza- tion, yaw, safety shut- down, and also allows remote control and remote system status reporting. OPERATION SAFETY Normal operation is initialized when wind speed reaches 14.3 mph. The unit is "motored" to synchronous speed and when synchronization is esta- blished the unit is placed "on-line". Normal shut- down includes reducing the unit's power output to nearly zero; followed by the feathering of the rotor as brakes are applied. Emergency shutdown circui- try separate from the main controller disables the unit immediately upon re- ceipt of an abnormal POWER OUTPUT (kW) oa o o 100 condition; i.e., over- @ 0 speed, or microprocessor 0 10 20 30 40 50 60 failure. WIND SPEED (mph) 15 3.2.3 Large Machines Several manufacturing and aerospace firms have entered the large wind turbine market. Most of these firms efforts were tailored to the U.S. Department of Energy's development program. Because of Washington's budget cutting fever the large machine program has been sharply curtailed. Several machines are in operation but no more are planned in the public sector. Private wind farm developers have contracted with two of the manufacturers for megawatt (MW) size machines. However, delivery on these orders is speculative at present. The majority of wind farm developers in the lower 48 will be using machines in the small to medium size range because they feel the technology is more well developed and the technical problems remaining are not insoluable. Large wind machines, on the other hand, should still be considered experimental. Economies of scale are gained by the large machines when multiple units are produced. These machines should not necessarily be disregarded, but should be considered at the time they are proven reliable and production costs are pinned down. TABLE 3.5 LARGE TURBINE CAPACITIES Manufacturer MW Capacity * Rotor Diameter Hamilton Standard 4 110 meters Boeing Engineering + Construction 2.5 91 meters General Electric 1 61 meters *Rated at 30 mph 16 94.7 Meter Turbine | GENERATOR TYPE & INTERFACE MODES This unit utilizes a 2.5 megawatt synchronous type generator producing power at. 12.5 -KV,. 66 hz. CONTROLS A microprocessor maintains operation of the unit. Remote status, alarm, and control functions are also utilized. OPERATION/SAFETY The unit will produce power at windspeeds be- tween 14 and 45 mph. The microprocessor will immediately shut down the unit should the windgener- ator suffer damage or begin to malfunction. POWER OUTPUT (megawatts) Oo 8 16 24 32 40 48 WIND SPEED (mph) 17 3.3 Axis of Rotation Wind turbine rotors spin about either a horizontal or vertical axis. Conventional wind turbines such as the Dutch windmill are known as Horizontal Axis Wind Turbines (HAWT). Darrieus turbines, on the other hand, rotate about a vertical axis and are known as Vertical Axis Wind Turbines (VAWT). FIGURE 3. AXIS OF ROTATION = —_——~ Poy = MVPS 7 VW SZSZR SASS VERTICAL AXIS TURBINE HORIZONTAL AXIS ROTOR Darrieus Rotor Conventional wind turbines employ one, two, or three- blade rotors transverse to the wind and normally house the generator and transmission aloft atop the tower supporting the rotor. Conventional wind turbines must turn (yaw) about the tower axis in response to changes in wind direction. 18 Vertical axis wind turbines (of which the Darrieus Eggbeater turbine is the most familiar), have two inherent advantages over those of their horizontal axis counterparts. First, the vertical axis of rotation allows the generator and gear train to be mounted at ground level, which aides servicing. Second, VAWT's are omnidirectional - they can accept the wind from any direction without swinging the entire rotation assembly about the tower axis. These advantages are offset somewhat by the limited tower heights used in Darrieus turbines; most phi configuration (Eggbeater) Darrieus are mounted atop a short (relative to the turbine's height) pedestal. Other vertical axis configurations are being developed. Phi configuration Darrieus tubines use curved blades that take on a modified troposkien slope when running, Straight blades can also be used in an H configuration, and in Delta, Diamond, and Y configurations. Two manufacturers in this country are developing small and medium size machines that use articulating straight blades. These blades rock or change pitch as they move along the carousel path. None of these giromills, as they are called, have been installed in Alaska. The British are designing a megawatt size straight-bladed VAWT for use in thier coastal waters. Though these other configurations are available, most of the effort to commercialize VAWT's has centered around the Darrieus turbine. 19 Darrieus wind turbines, contrary to popular belief, can perform just as effeciently at extracting the energy in the wind as the more conventional wind turbines, according to tests conducted by Sandia National Laboratories. These machines have not been as commercially successful as HAWT's primarily due to the limited engineering experience with these designs. They do hold the promise of being competitive with horizontal axis configurations because of their simplicity and ease of manufacture. Currently, Alcoa is proceeding with development of medium size Darrieus turbines in this country, and Dominious Aluminum Fabricating (DAF) of Ontario is doing likewise in Canada. 20 3.4 Generator Type 3.4.1 Introduction A further refinement in classifying and describing windgenerators is to distinguish them by the type of generator they employ. Each of the four types discussed present a different set of output characteristics and as such must be treated differently by the utility. Additionally, the safety requirements for a windgenerator in protecting utility maintenance personnel on grid-interconnected machines are different for each classification. Four basic wind-turbine designs were considered: synchronous and induction generators, and line and self- commutated inverter systems. The induction generator system was judged to be of principal interest, because many manufacturers have selected it over other possible designs in the small to medium machine sizes. Both inverter systems were studied based on characteristics available in published literature, with special focus on the line-commutated inverter. There are, however, many possible inverter circuit designs. This study relied on the basic inverter principles assuming specific DC source characteristics, where appropriate, rather than specific wind-turbine systems offered by manufacturers. General electrical characteristics of machines and inverters were used rather than specific characteristics of state-of- the-art small wind turbines. This is because the small turbine manufacturers do not presently provide sufficiently detailed electrical diagrams and test data to identify electrical characteristics due to proprietary concerns. 21 3.4.2 Direct Current Generators DC power can be developed by two methods in WECS. The simplest is the use of a brush-type DC generator in which the voltage produced varies as a function of the rotor rpm. The second method is slightly more complex and uses an alternator. The alternator produces a variable frequency output as a function of wind velocity. The output is then rectified to produce the DC voltage. The magnitude of the output voltage can be controlled in many cases by changing the field current- e.g., inserting different resistance values into the field windings. During normal operation the units are usually self- exciting. Most modern DC windgenerators use alternators because of their lighter weight, availability, reliability and reduced maintenance. Most utility applications require AC power as the DC must be inverted to AC before use. There are two types of inverters which will do this; synchronous and asynchronous, a) Synchronous Inverters (SI) are less expensive and are available in sizes from 2 kw to 1.5 megawatts. The SI is designed to synchronize with a source such as a diesel generator to save fuel. These line-commutated inverters are voltage dependent sources that cannot feedback into the utility's system without a source of voltage. b) Asynchronous Inverters (AI) provide their own reference for producing sine-wave power and are available in sizes from 100 watts to several megawatts. AI's are used as stand-alone power sources and are capable of being synchronized with each other or with a utility grid. These self- 22 commutated inverters can feed back into a utility grid (even when de-energized) because they are voltage sources. 3.4.3 Induction Generators The inductive type type generators are commonly found on small utility intertie wind turbines. With minor control modifications a commercially available, relatively inexpensive induction motor is utilized. At a pre-set cut-in wind speed the motor is brought on line causing a momentary surge of reactive current to be drawn. As the windspeed increases, the power factor increases to within utility tolerances and power is fed into the grid. Power output will increase with windspeed until the hysteresis point of the generator is reached at which point output starts to drop off. Because induction generators are voltage dependent they will not back feed a de-energized section unless very specific and non- normal distribution system conditions are present, such as a capacitor bank or some other voltage source. Due to the reactive power requirements of the induction generator, there is a limit to the capacity that can be supported in a distribution and generation system at one time. Careful consideration must be given to the best mix of generation types from both an efficiency and safety standpoint. 23 3.4.4 Synchronous Generators Most of the medium sized turbines and all of the large machines employ a constant speed synchronous generator. Typically these turbines operate in a narrow band of wind speeds at peak efficiency and are designed to "spoil" the wind to maintain a regulated RPM. Additionally, these machines are microprocessor controlled so that their output is constantly monitored to maintain utility tolerances. Since these turbines are capable of being a voltage source they can provide a leading power factor. They are also capable of energizing a downed line and must be programmed to shut down when a fault is sensed. 24 3.5 Wind Generator Controls The control components of wind electric systems are nearly always sold as a package with the windgenerator itself. The complexity of the controls will vary between models of windgenerators, and are usually greater for larger and more expensive machines. The following controls are germane to the windgenerator only and are required regardless of size of turbine or number of machines on line in a utility grid. One control common to all windgenerators is a manually operated shut down system. This allows the windgenerator to be shut down for maintenance, emergency situations, or if the power quality falls below a preset limit. Nearly all machines also have a control device to automatically brake the machine (or turn it out of the wind) when wind speed reaches a dangerous level (the cut-out speed). This can be accomplished by connecting the controller to an anemometer mounted on the tower which senses wind velocity. Its signals are sent to the controller which shuts the machine down at some pre-set wind velocity or by sensing rotor rpm or generator output. There are many other control functions which may or may not be included with a windgenerator (or may be optional equipment). A useful control is one which restarts a windgenerator that has been shut down due to high winds after the winds subside. In most larger windgenerators, overspeed control is accomplished by hydraulic or electric drives which feather the blades, deploy tip brakes, or turn the machine out of the wind. These controls can be actuated by an anemometer, by a tachometer on the rotor shaft, by a high voltage or high current sensor, or by some combination of these. In many 25 smaller machines, in contrast, overspeed is prevented by mechanical means centrifugally activated. Large wind machines do not use a tail vane to point them into the wind. Instead, yaw control is performed by a wind direction sensor (electronic wind vane) which actuates a drive mechanism to rotate the windgenerator. Other windgenerator control functions can include automatic braking of the machine when excessive vibrations are sensed. On most utility intertie machines, controls are built into the design so that when the utility power is off the windgenerator is not producing power. This is to prevent backfeeding power into the utility's lines whenever a repairman may be working on them. Also, some machines have controls which sense the frequency of the sine wave output and other power quality characteristics to prevent the windgenerator from providing power of poor quality to the utility. Such controls also prevent the utility from harming the windgenerator with low-voltage conditions. 26 3.6 Conclusions and Recommendations Despite the proven nature of the residential sized windgenerators, they represent a poor investment from a utility perspective in meeting capacity needs. The difficulty of maintenance procedures and less assurance of plant availability, particularly under user ownership, would reduce both energy and capacity value. Problems associated with the distribution system such as possible modifications to the present relaying, fusing, and voltage control systems to assure prompt fault clearing, personnel safety, and the prevention of damage to utilization equipment will need resolution. Special metering and control equipment at each residential site would involve additional costs and difficulties which in combination could outweigh any advantages for utility application of small turbines. However, individual load center applications of a commercial, institutional or industrial nature where siting is more flexible and technical considerations more controllable may be more attractive, especially for the turbines with a greater than 10 kw output. The medium sized turbines are the most attractive from a utility standpoint. Over 10,000 hours have been logged on machines in the 200 kw size supplying power to remote diesel grids. The extensive DOE/NASA testing of the MOD-OA turbines have proven their ability to provide firm reliable power in Clayton, New Mexico; Culebra, Puerto Rico; Block Island, Rhode Island; and Oahu, Hawaii. WTG Energy System, Inc. has had operational their privately developed 200 kw unit on Cuttyhunk Island, Mass. since June 1977. Having installed a unit in Nova Scotia and the coast of Oregon, WTG has shown this size to be commercial and practical. These turbines utilize the 27 synchronous generator, and as such are programmed to operate efficiently while either intertied to a diesel generator set or in a stand alone capacity with the diesel's on standby. At this time, the large megawatt scale turbines are best not considered practical for Bristol Bay until they are better proven in the lower 48. Additionally, their benefit to the small grid's stability is questionable when compared to multiple medium sized units. The vertical-axis turbines are also not yet well developed enough for use in rural Alaska. 28 4. STORAGE, MONITORING & SYSTEM INTEGRATION EQUIPMENT Storage devices have utility ap- plications, but are very site specific or expensive and in some cases unprov- en. Optimism is expressed for the future, particularly if used in con- junction with load management in an integrated system. Considerable data needs to be collected and four levels of monitoring are described. Genera- tion equipment compatability and load Management are presented with reference to utility grid integration with multiple remote voltage sources. 4.1 Introduction This section discusses three different but related topics. Storage apparatus information is presented to list the various options, but with the understanding that any scenario (including storage mediums) must be very specific. This is because of the system dependent nature of storage requirements. Both the load characteristics and supply alternatives must be integrated to determine the level and type of storage required. Thus, a detailed monitoring program is necessary to determine these needs. Once the appropriate level of data has been collected the entire load/supply situa- tion can be effectively managed. Therefore, the last topic discussed is system integration parameters. 4.2 Storage Apparatus @ 4.2.1 Batteries Lead-acid batteries are by far the most common type of energy storage device for wind electric systems. "Deep cycle" batteries are preferred. These batteries are designed to sustain repeated deep discharge without damage, and are commonly used in forklifts and golf carts. Batteries for wind electric systems are costly, so it is desirable to use them under conditions which will result in their most efficient operation and longest life. Consequently, batteries as a storage medium are best suited for individual cabin or homestead use where the owner can provide the proper care. Batteries require the periodic addition of water and must be protected from freezing. The owner must see to it that the batteries are never charged or discharged at too high a rate. Battery sets must also be fully charged periodically to equalize the charge on the er individual cells. Keeping batteries from overheating can be a problem, though this will rarely be of concern in the Bristol Bay Area. For loads larger than a single homestead, the number of cells involved becomes overwhelming. The maintenance costs alone for lead-acid batteries would be prohibitive ina utility sized battery bank used for anything other than very short term storage. Significant advances are being made in battery technology but it may be as long as ten years before they become commercially available and inexpensive enough to use for a village-scale storage scheme. If the maintenance requirements, cost, and efficiency can be improved in the future, a battery system could be very worthy of consideration. 4.2.2 Compression Air Storage Compressed air storage involves using all windgenerator power not immediately needed for other uses to operate an air compressor that pumps air into either a metal tank or an underground storage vault. To retrieve the power, the process is reversed, and the compressed air drives a motor-generator combination. For some uses the reconversion to electricity would be unnecessary. The compressed air could be used to drive tools and machinery directly. Air tools, for example, are commercially available. The principle drawbacks to compressed air are the low conversion efficiency and the large volume of storage required. No known naturally occuring. storage exists in the study area, which is considered a prime requirement to using compressed air storage on a village scale economically. 4.2.3 Pumped-Hydroelectric Pumped-hydroelectric storage is accomplished by pumping water uphill to a reservoir and later using this stored water to drive a turbine-generator. In most pumped-hydro systems, the "pump" and the "turbine" are one and the same machine; their operation is reversible. There are a number of pumped- hydro stations operated primarily as peaking facilities by electric utilities using off-peak power to pump the water back up to the forebay. Finding a favorable hydro storage site is difficult; finding one in proximity to a favorable windgenerator site is even more so. In addition, the capital cost for these systems is high and their conversion efficiency is low. 4.2.4 Hydrogen Storage Hydrogen storage involves electrolyzing water into hydro- gen and oxygen gas and storing the hydrogen. The flammable hydrogen can then be used as a fuel ina more or less conven- tional motor-generator system or in a fuel cell system. The fuel cell is a device which converts the chemical energy of the hydrogen-oxygen reaction directly into DC electricity with higher efficiency than conventional methods of power genera- tion. In operation it is similar to an electrolyzer working in reverse. Hydrogen storage appears to be a reasonably good storage method in theory, although it wouldn't match the efficiency of a conventional battery. At the present time few, if any, of the major components (electrolyzers, hydrogen storage systems, fuel cells, or hydrogen-fueled motors) are readily available. Even if these components could be specially made they would be very expensive. 4.2.5 Flywheel Storage Flywheel storage is accomplished by using excess power in an electric motor to spin a flywheel; the energy is thus stored as kinetic energy. Later, the spinning flywheel can be reconnected to the motor, which will then generate electricity @ by withdrawing the stored kinetic energy. Like hydrogen systems, flywheel storage is in the developmental stage. Research is being done for applications in many fields, but no practical systems are commercially available. In order to store significant amounts of energy ina flywheel, large masses must be spun at very high speeds. This creates two major problems. One of these is that a heavy flywheel must be perfectly balanced so that the bearings will not be destroyed, the other that special materials must be used that can withstand the tremendous stress. 4.2.6 Thermal Storage Thermal storage uses electrical resistance heaters or a heat pump to warm up a material in a heavily insulated container. This hot material can then be used later to boil a fluid (water or ammonia, for example) and produce an expanding vapor which can then be used to drive a conventional turbine- generator. A thermal storage system would have a low efficiency for electrical power production. Thermal storage is more practical when heating is the end use, because less energy is lost during transfer from storage. Wind systems have been designed and built based on the principle that surplus power be used to heat water, which can later be used for domestic hot water uses or for a hot water space heating system. This, of course, is just indirect electric heating, which is almost always more expensive than any other means of heating. As a result, this is not usually a cost-effective idea unless the windgenerator is generating power which otherwise would be wasted. Another form of thermal energy storage which is being demonstrated on a commercial basis and is useful in some cases is to store cold, not heat, and use it for cooling purposes. Surplus electricity could be used to run a freezer. This could be advantageous for a community freezer in a village during the summer when fish and game need to be frozen for winter use. 4.3 Monitoring Equipment 4.3.1 Introduction A classification for levels of monitoring has been defined by Ramsdell and Wetzel in "Wind Measurement Systems and Wind Tunnel Evaluation of Selected Instruments." The four classes of monitoring systems based on storage capabilities are: CLASS DATA STORAGE CAPABILITY i None Lt Limited to a single storage register III Processed information stored in data logger with more than one storage regis-— ter, but sequential information lost. Iv Processed or unprocessed information with sequential information retained. 4.3.2 Class I Systems Class I systems-have no storage capabilities and require a human observer to record data. This system is used by the National Weather Service (at their manned sites). For the purpose of site evaluation care should be exercised that the operator maintain a somewhat regular schedule when recording data so as not to "bias" the data; i.e., record velocities only when the wind is blowing. The same methodology applies to monitoring a WECS's performance. Typical parameters monitored would be: 1). Wind Speed 2). Wind Direction 3). Temperature 4). Humidity/Barometric pressure 5). KW output (Power) 6). KWH (Work) (a class II sensor) 7). Other WECS parameters i.e., Volts, Amps, Running Time (class II) The advantage of Class I systems is low initial cost. However, the expense involved in reading and tabulation of the data may be somewhat prohibitive. This is especially true if a reasonable degree of accuracy is desired. Operator training is minimal and the primary goals in training would be to stress consistency and vigilance. Class I disadvantages would be a loss of accuracy due to meter reading errors of extraplation rounding, etc. Another disadvantage is that the processing of the data obtained to develop wind power spectrums and windgenerator performance must all be done by hand. This is true even if a computer is used, as the data must still be entered manually, and the possibility of human error is increased. 4.3.3 Class Il Systems Class II systems do have storage capability, though limited to a single parameter. This type of storage applies to two particular parameters: wind speed and kilowatt hours. The device for wind speed is called a wind odometer and records a value related to "miles of wind" that pass the anemometer. This value can then be processed (by hand) to produce an average wind speed over whatever observation period is used i.e.: hourly, daily, weekly, or monthly. The kilowatt hour meter is analagous to the windspeed odometer in that it records total energy produced by the windgenerator. Class II advantages are that the summing of parameters takes place continuously and thus more data is being collected. In the case of wind monitoring, the readings can be made less frequently than a Class I device and provide better average velocity indications. For power measurements the KWH meter represents the only method of accurately depicting total power flow. Class II disadvantages are as follows: 1) The applications are limited i.e., a cumulative wind direction sensor reading is somewhat meaningless; 2) They tell nothing of the diurnal characteristics of the parameter being measured. They could be compared to the odometer of an automobile in that it tells only the number of miles driven and not whether they were all highway driving, city stop-and- go or running bootleg whiskey in the hills of Tennessee. 10 4.3.4 Class Ill Systems Class III devices pertain mostly to wind power potential development. They process the wind data and display several combinations of accumulated results. Processing usually involves raising the discrete data values (windspeed) to various powers (2nd, 3rd and possibly 4th) and summing the results in a cumulative display register. These values are then used to develop the power in the wind and further aid in obtaining an idea of the wind spectrum using statistical analysis. A better picture of the wind's potential is obtained with this device when compared against a class II system. Class III advantages are that the data obtained is already summed and preprocessed for analysis purposes and provides an indication of the diurnal characteristics of the wind at the site in question. Remote operation is possible for unmanned sites. Class III disadvantages are that individual observations on wind speed are lost and the devices may require additional equipment to retrieve the stored data. 11 4.3.5 Class IV Devices Class IV devices have the capability of recording discrete data points such as wind speed as individual observations and have the capability to process and present summarized forms of the data as well. The parameters monitored are limited only to the availability of sensors capable of providing an output comparible with the device in question. In most cases any sensor that provides an electrical output is useable with proper signal conditioning. The information obtained can be stored in the form of strip charts that maintain a running record of the parameters monitored. However, removing data from the strip charts can become a tedious undertaking and lends itself to errors in reading and recording data for further processing. A solution to the problems is found in the new generation of magnetic storage devices that employ microprocessors to govern their operation. The data is stored on magnetic digital cassettes. There is currently a commercial system available that allows on-site analysis and is in itself a relatively sophisticated computer. These systems are extremely flexible and can be used for windgenerator performance monitoring as well as analysis (in the case of the computer controlled systems). Class IV advantages are: 1) The storage of real-time data maintaining individual occurrences in sequence; 2) Extreme flexibility as far as parameters to be monitored; 3) Multi-channel (parameter) capability; 4) On site analysis of data is available; and 5) Data collection may be initiated prior to the development of a particular analysis methodology and different approaches used on the same data as it is stored in its original form. 12 Class IV disadvantages are: 1) The high cost in setting up the system as well as its purchase price; 2) Although some do lend themselves to remote applications, they generally are not able to function in extreme environmental conditions; and 3) Devices that employ strip chart recorders are generally difficult to use when retrieving data. 13 4.4 Systems Integration It is possible to gain the economics offered by storage (increased consumption of power when wind is available, the reduction of power use when it's not) through region wide system integration. With a mix of different machine sizes and Capacities spread across a diverse region there is a certain probability that a level of capacity will be available at all times. Studies done by the Electric Power Research Institute conclude that a capacity credit can be given to wind genera- tion capacity on a grid system, depending on the grid charac- teristics and the wind regime. Substantial operating experience on intertied systems has demonstrated the ability of a wind generator to run a remote grid unassisted if a load dump is employed to maintain a reserve margin. The key toa sustained high penetration of wind energy on a grid is enough knowledge of the wind resource so that utility personnel can plan operations around its availability. The study area offers diverse terrain, from its coastal environments to its mountain passes, and is large enough in area to make for a good likelihood of this occurring if all the villages, all the wind turbines, and all the other generating sets were interconnected. 14 4.4.1 Generation Equipment Compatibility As already discussed, the type of generators on line and their location on the distribution system are critical to system stability. More experience needs to be gained before anything conclusive can be stated about voltage-dependent wind systems and their value to a grid. It is clear, however, that there are limits to the penetration level these type of units can efficiently make. The best currently available information indicates 30% penetration is a reasonable limit, and for purposes of this study is deemed a maximum. 4.4.2 Load Management Most utility systems in the country today can benefit from end use load management. Because of the diurnal varitions in demand, small grid systems such as found in Bristol Bay will typically have peaking requirements many times greater than average demand. The major contributors to the problem are the large users such as the schools, water plant and commercial users. Distributed microprocessor controllers in these key facilities can save a consumer as much as 30% through use of the following techniques: Demand Limit Control reduces the peak rate of electrical energy usage. Demand Control measures the rate of energy consumption in the building and when the rate exceeds a limit selected by the owner, the Demand Limit Control will temporarily turn off energy-consuming loads on a preprogrammed basis. When the energy usage rate drops below the limit, equipment is automatically restored to normal operation. The type of equipment this would apply to would be: freezers, pressure pumps, fans and possibly some lighting and resistive heaters. 15 Duty Cycling is defined as repetitively turning energy- consuming loads OFF and ON during a preprogrammed cycle. The purpose of the Duty Cycler is to reduce unnecessary equipment operation and also to increase equipment efficiency. A sophisticated Duty Cycler will match the amount of duty cycling with actual load conditions. For example, as outside air temperature drops, the load on a heating system increases, and the load management system reduces duty cycling. Time-of-Day Programming allows the owner to individually program precise OFF and ON times for energy consuming devices with different programs for each day of the week. The Time- of-Day Programmer is also a labor-saving device by automating those tasks that are frequently overlooked in manual operations. These distributed load management systems can easily be programmed to respond to a signal from a central controller operated by the utility which requests loads be dropped or added to maintain maximum generation efficiencies. Fail Safe operation is thus made possible by programming the remote units to be independent of the central controller in the event of loss of a signal. With additional software, the utilities' central load manager can perform billing functions and provide operation and maintenance information, as well as minimize record keeping requirements. 16 4.5 Conclusions and Recommendations According to computer modeling done by General Electric for the Electric Power Research Institute, dedicated storage to wind generation equipment is not beneficial, either from the viewpoint of wind power viability or minimum generating system cost. Non-dedicated, general system storage, however, has many times been shown to be economic when operated and dispatched as part of the total generation system, and there are many successful pumped storage hydro plants in operation on utility systems today. There is considerable research and development work underway to produce new storage systems which can be used in areas where pumped storage hydro is impractical. Monitoring to determine utility load characteristics and wind power availability is best done with a microprocessor based data collection system (class IV). This must be tempered however with preliminary screening, to determine the appropriate level of collection warranted due to the increased cost associated with more sophisticated levels of data gathering. Load management technologies should be considered regardless of the generation mode. The benefits in peak shaving and the ability to optomize generation efficiency are Significant. With higher degrees of penetration of wind equipment, load management becomes more necessary to maintain system stability. 17 oD. POWER PRODUCTION ANALYSIS This section analyzes the potential contribution to . the electrical of “wind power Bristol “Bay demand forecast for the year 2000. The penetration levels are based around a matrix system consisting of two distinct categories of Parameters. Several combinations of these two categories are presented. Tre $27 5t set: of parameters assumes three levels of penetration in the region: i) 6188 penetration without utility 2). 583 penetration with utility and 3) 70% with load Management and concerted involvement; involvement, penetration utility involvement. The second set of parameters assumes three different utilization scenarios: 1) a disaggregated base case; 2) all villages intercon- nected; ands 3) a EO network grid in the region. Several tables. are presented illustrating the potential number of genera- tors required for each case; they are broken down into size classifications that are representative of commercially available machines penetration and at each given intertie scenario. Throughout the method- ology presented herein, the assumption is made that several small and medium size windgenerators are desired over single large Though arguments for this course units. several of action are presented, the major benefits revolve around availability of both machines and replacement hardware, as well as the reliability of thé grid to Provide power in case of windgenerator failure or down-time. 5.1 Introduction In Section Three, the size and type of wind turbines available today or expected to be available in the near term were described. A methodology was outlined for determining the potential performance of machines in the various wind regimes of the project area. Because village utilities are concerned about the dependability of power from wind generators, and considering the variability of the resource, it is necessary to look at the maximum number of machines possible within a village generating system at selected levels of grid penetration. Once the maximum number of machines has been found, the technique described in Section Three can be used to calculate the energy contribution from the selected mix of machines within each village or zone of the study area. 5.2 Methodology Wind machines can be added to a generating system through either private action-such as when homeowners install a wind turbine for their own use-or through institutional action, when the village utility installs a large wind turbine(s) for community use. In the present economic climate (low-interest State Alternative Energy loans, high electric rates) homeowners and small businesses will continue to install small wind machines irregardless of action by village utilities. Consequently, this study has assumed that 10% of the Year 2000 electrical load will be met by small wind systems. Utilities have access to greater financing than homeowners, and can take advantage of the expected economies of scale offered by larger but more expensive wind turbines. Moreover, the utilities are able to manage and maintain larger units. As a result, two levels of penetration have been chosen for integration into a small utility by wind systems: 30% and 70%. These levels of penetration incorporate the 10% to be contributed by small private machines. Utilities are capable of handling 10% penetration without any alteration of their generating system or its management. At 30% penetration some load management may be advantageous. At 70% penetration, load management and complete integration of the wind systems with the utility's other generators is necessary. Data to date indicates that load growth in the study area is approximately 6% per year or roughly an average of the high and low growth forecasted by R.W. Retherford Associates ina February, 1981 report for the Alaska Power Authority. The following projections assume an average of Retherford's high and low forecasts. LOAD FORECAST YEAR 2000 Village kW MWh/yr Dillingham 6155 30,744 Naknek/King Slamon 7220 37t,.128 Clarks Point/Ekuk 1139 3,205 Egegik 1085 2,688 Ekwok 207 902 Iguigig 87 380 Koliganek 217 946 Levelock 198 863 Manokotak 340 1,481 New Stuyahok 250 1,101 Portage Creek 719 346 Iliamna/Newhallen 1105 5,210 TOTAL 17,852 84,994 From the load forecasts, the maximum capacity (kW) contributions at each pentration level from the wind turbines were estimated. Once the maximum capacity contribution was determined the next step was to project a machine mix and the number of machines of each type that would be needed. The concern here is with potential maximum output of the wind systems. Consequently, neither MPO or rated capacity of the wind turbines being considered could be used. This study used each machine's potential kW output at an instantaneous wind speed of 30 mph (assumed to be peak output on the machines investigated), with the smaller machines performing at an efficiency of 20% and the bigger units operated at a 30% efficiency. This approach resulted in estimates roughly approximating the maximum rated output of several commercially available wind turbines. SMALL & MEDIUM SIZED TURBINE OUTPUT 30mph/25% Efficiency Rotor Diameter Maximum Output 4 meter 3 kW 7 meter 10 kW 10 meter 25 kW 17 meter 69 kW LARGE TURBINE MAXIMUM OUTPUT 30mph/30% Efficiency Rotor Diameter Maximum Output i; 25 meter 200 kW 91 meter 2,500 kW The 30% penetration level is made up of the 10% contributed by small machines and 20% of maximum capacity by medium size machines ( inthis case the 17m and 25m turbines). Similarly, the 70% penetration level is comprised of 10% from small machines and 20% from medium size machines, with the remaining 40% from the large turbines. As mentioned, the 30% and 70% levels assume utility involvement. Utilities generally prefer the biggest machine possible to gain economies of scale. However, there are also advantages to a multiple number of medium sized machines, particularly in the remote villages within the project area. With multiple smaller units there is less loss of capacity when any one turbine is down for repairs or cycled-off as load declines. Also, it is easier to stock spare parts when more than one machine is in the same vicinity. The value in multiple units is assumed in our scenario by limiting the medium and large machine mix. Whenever there was insufficient load to use the maximum combined output from at least three to four units, the load was met by a larger number of smaller machines. Below is an elaboration of the argument for multiple units of small to medium size wind turbines: 1) Smaller machines are easier to maintain since the moving parts are smaller and lighter. 2) Smaller units are manufactured in greater numbers, thus making parts more readily available. 3) The more dispersed the machines are around a grid or terrain, the higher plant factor will be achieved because of the microclimate effects. 4) Reliability is increased because if one unit fails a smaller percentage of capacity on line is lost. 5) The controls are typically more complicated as a windgenerator gets larger. 6) Small and medium size wind machines can be added incrementally to the system as load increases because of their short lead time for construction. This allows for flexibility in forecasting the load growth. The number of new units planned can be altered to reflect change in demand. After the maximum number of machines that can be absorbed in the system at each penetration level is found, the potential energy output (using the rotor diameter and the wind power in the area where the machines will be sited) is calculated. An important consideration in both the 30% and 70% levels of penetration is power quality and reactive Vars needed to support the grid network. Thus, an important requirement in operating a grid when the wind generators are providing a significant portion of the load requirements is use of a synchronous generator. Both the 25m and 9lm turbines use the more expensive controls and circuitry required to maintain a leading power factor. Because of this, the smaller villages in the non-intertied scenario may have potential problems with high penetration levels using smaller line-commutated machines. 5.3 Power Production The following figures tabulate the machine mix at each of the three penetration levels for the Base Case; i.e., each village remaining independent of the others (except for Clarks Point and Ekwok where their close proximity would make an intertie probable). The same estimates for a series of interconnection possibilities where then tabulated. The first case assumes that all villages within the study area are interconnected. The second case assumes that zones (as shown in Figure 5.5) C, D, and E are interconnected and zones A and B form a second network. It was assumed that the wind turbines would be sited within the windiest areas of each network rather than equally dispersed throughout. Consequently, in Figure 5.4, when all the villages are interconnected the machines are sited in an area of Wind Class 5. In similar fashion, Figure 5.6 uses a Wind Class of 5 for the interconnection of Zones C, D, and E. A Wind Class 3 was used for the interconnection of Zones A and B. FIGURE 5.1 DISAGGREGRATED BASE CASE POTENTIAL NUMBER OF UNITS/ANNUAL ENERGY CONTRIBUTION (MWh) 10% PENETRATION LEVEL Power Demand 4m Tm 10m Total Village Class (kW) #units(MWh/yr) #units(MWh/yr) #units(MWh/yr) MWh/yr Dillingham 2 6155 104/577 18/292 5/172 1040 Naknek/King Salmon 5 7220 120/1,330 224425 6/410 2460 Clarks Point/Ekuk 3 1159 19/141 6/130 = 271 Egegik 5 1085 18/200 3/98 1/68 366 Ekwok 2 207 71/39 = — 39 Iguigig 4 87 3/37 = = 37 Koliganek 2 217 4/22 1/16 - 38 Levelock 3 198 3/22 + = 22 Manokotak 3 340 8/59 1/22 — 81 New Stuyahok a 250 5/28 1/16 = 44 Portage Creek 3 79 3/22 - - 22 Iliamna/Newhalen 3 1105 19/140 3/65 1/46 251 oL FIGURE 5.2 DISAGGREGATED BASE CASE POTENTIAL NUMBER OF UNITS/ANNUAL ENERGY CONTRIBUTION (MWh) 30% PENETRATION LEVEL Power | Demand Total Village Class (kW) 4n Tm 10m 172 25m MWh/yr Dillingham 2 6155 104/577 18/292 $/171 9/872 3/870 2782 Naknek/King Salmon 5 7220 120/1330 22/715 6/410 14/2720 3/1740 6920 Clarks Point/Ekuk 3 1159 19/141 6/130 9/410 - - 681 Egegik 5 1085 18/200 3/98 1/68 3/582 = 984 Ekwok 2 207 71/39 4/65 - = a 104 Iguigig 4 87 3/37 2/54 a mn - 91, Koliganek 2 217 4/22 5/81 i = - 103 Levelock 3 198 3/122 4/86 = = = 208 Monokotak 2 340 8/59 8/172 - - 231 New Stuyahok 2 250 5/28 6/97 - - - 125 Portage Creek 3 719 3/22 3/65 - - - 87 Iliamna/Newhalen 3 L 1105 19/140 3/65 9/410 - - 615 tb FIGURE 5.3 DISAGGREGATED BASE CASE POTENTIAL NUMBER OF UNITS/ANNUAL ENERGY CONTRIBUTION (MWh/yr) 70% PENETRATION LEVEL Power Demand Total Village Class (kW) 4n 7m 10= 17= 25m MWh/yr Dillingham 2 6155 104/577 18/292 21/2030 21/2030 6/1740 4,810 Naknek/King Salmon 5 7220 120/1330 22/715 6/410 25/4850 7/4050 11,400 Clarks Point/Ekuk 3 1139 19/141 6/130 9/410 8/1030 = ad Egegik 2 1085 18/200 3/98 1/68 7/1360 = 1,730 Ekwok 2 207 71/39 8/130 3/68 = = 237 Iguigig 4 87 3/37 5/136 - - - 173 Koliganek 2 217 4/22 6/97 3/103 ee = 222 Levilock 3 198 3/122 4/86 3/137 = = 345 Manokotak 3 340 8/59 9/194 5/228 - - 481 New Stuyahok 2 250 5/28 6/97 4/137 - - 262 Portage Creek 3 19 3/22 6/130 - - - 152 Iliamna/Newhalen Ss 1105 19/140 5/108 9/410 7/903 = 1,560 oe FIGURE 5.4 ALL VILLAGES INTERCONNECTED POTENTIAL NUMBER OF UNITS/ANNUAL ENERGY CONTRIBUTION (MWh) 10% PENETRATION LEVEL Power Total Class 4n Ta 10a 5 18,099 #units 301 55 14 MWh/yr 3,340 1,790 956 6,100 30% PENETRATION LEVEL Tn 10m 17m 25m #units 301 55 14 13 14 MWh/yr 3,340 1,790 556 2520 8,100 16,700 PENETRATION LEVEL 4m In 10m 17m 25m 91m 5 #units 310 $5 14 13 14 3 33,900 50,600 FIGURE 5.5 TRANSMISSION LINE INTERCONNECTION aR geal ( ; il /NONDALTON ( 7 ee Sy Meas Zone E wianya 7 -— ‘ \ mz 7 KOLIGANEK@ \\ \ Sl Zone B } ( NEW STUYHOK®, sa ennorg? Zone CH -_ ALEKNAGIK or fone AN AG (fF MANOKOTAK ¢’ } 2 e BRISTOL BAY REGION | 5151 “INorth 0 10 20 30 40 50 13 veh FIGURE 5.6 TWO NETWORK GRID SYSTEM POTENTIAL NUMBER OF UNITS/ANNUAL ENERGY CONTRIBUTION (MWh) 10% PENETRATION LEVEL #units MWh/yr 1,790 940 550 3,280 #units 140 26 6 MWh/yr 1,040 562 274 1,876 30% PENETRATION LEVEL 4n In 10m 17m 25m Cc, D, Hii 5 #units 161 29 9 14 5 MWh/yr 1,790 940 614 2,720 2,900 8,964 A, B [ 3 #units 140 26 7 14 4 MWh/yr 1,040 562 274 1,800 1,544 5,220 el 70% PENETRATION LEVEL: 4n Tm 10m 17a 25m 161 29 10 17 19 1,790 940 6 83 3,300 11,000 17,700 140 26 9 14 17 1,040 562 274 1,810 6,560 10,200 5.4 Conclusions and Recommendations The proceeding tables are not a recommended or predicted mix of wind turbines; rather they are representative of a reasonably diverse grid system. It would be to a utilities advantage to standardize the turbines for maintenance purposes. However, the size and type machine selected is very system dependent and site specific, and may belie standardization. Based on the diverse mix chosen in our methodology, the following table represents the annual energy contribution to the total electric consumption in the region for each scenario: FIG 5.7 PERCENT ANNUAL ENERGY CONTRIBUTION FOR EACH SCENARIO (total of all villages) Penetration level Contribution To Total Energy Demand Base Case | Two Network [All Interconnected 10% | 5% 6% 1% 30% 15% 17% 20% — 27% 33% 60% The advantage cf interconnecting the village is seen clearly in terms of energy contribution. Further benefits in load leveling, increased reliability and economies of scale are possible with the larger grid networks. The 70% penetration level does not appear to be practical in the base case plan because of the fairly small increase in demand contribution over the 30% level. It is only when all villages are interconnected that this higher penetration level becomes justified. 15 6. RESTRAINTS IDENTIFICATION THIS: SEeCtIOn: attempts. to identify any constraints which might impede a plan to develop wind energy itt; he Bristol Bay Region. Environmental factors are discussed in detail with potential impacts broken into the construction and operational phases. Safety concerns are discussed with a risk analysis describing possible failure modes and their consequences. Regulatory and regional restraints were identified to provide a guide to a planner unfamiliar with Alaska. In general, the probable impacts and restraints are site specific and can be mitigated through careful planning and analysis of the problems. 6.1 Assessment of Probable Environmental Impacts 6.1.1 Introduction Possible environmental consequences associated with wind energy systems include primary impacts; i.e., those directly related to the construction, operation and decommissioning of the windgenerators. In some cases, site location can exacerbate or minimize the machine's impact on the environment. Secondary impacts such as those environmental effects associated with the manufacturing of the basic materials (steel, aluminium, etc.) used in constructing wind turbine machines are considered inconsequential compared to U.S industrial production and are not discussed in this report. The primary impacts are broken into those caused by construction activities and those caused by operation of the turbines. When no distinction is made herein about the size of a windgenerator, it is assumed that the smaller turbine would have less of an impact. 6.1.2 Construction Impacts (a) Site Preparation: The area immediately surrounding the proposed location will require clearing for an adequate staging area. This clear zone need only be large enough for the wind turbine and erection equipment. This area should be fenced off for safety reasons. (b) Access Roads: In most cases access roads will need to be constructed. These roads could be seasonal as in a winter ice road or a summer haul road. These would be used exclusively by four wheel drive vehicles and would have the same requirements and (c) (qd) (e) impacts as transmission line haul roads. Year round access to the site by road after construction is not necessary. Construction Equipment: Most windgenerators do not need a large mobile crane because the turbine and tower design include provisions for erection of the system using a simple gin pole. The gin pole would be erected on site and could be retained at the site to facilitate possible future repairs. The foundations used in Alaska typically involve pilings or some type of deadman anchor system, and not necessarily expensive concrete pads. A pile- driving rig or backhoe is thus required for installation of anything but the smaller turbines. Technical and Construction Personnel: Preparation of the site will require a limited number of workers to operate grading equipment, place the foundation, and install transmission cables. On a larger megawatt scale turbine a small number of outside construction, technical and supervisory personnel, generally on the order of less than 40 or 50, will be required during site preparation and windgenerator construction activities. No housing or commercial development is expected to result from the construction project. Restoration of the Site: After construction or upon decommissioning the site can be restored or allowed © to revert back to its natural state. Such restoration may include refilling of excavations with earth, planting of grass or other vegetation, Or other actions needed to satisfy local government requirements and/or sound environmental practices. 6.1.3 Operational impacts (a) Biophysical: The biophysical environment will require that site specific parameters be studied. These would include: Geology, Topography, Seismology, Hydrology, Climate, Vegetation, Mammals, Insects and Birdlife. No significant impact is anticipated on any of these parameters even with the largest turbines. This is based on environmental impact assessments performed for the DOE-MOD program for specific wind turbine sites. Birds: DOE analysis has shown that there are potential bird kills by rotating blades at a wind turbine. The primary hazards relate to nocturnal migrants when considerably below their normal flying altitude due to storm or overcast conditions or when landing near the site to feed or rest. In addition, there may be some hazard to low-flying diurnal migrants that cannot see the turbine due to fog or low-lying clouds. However, no significant bird kills have been recorded to date at any of the wind turbine sites. (b) Animals: Animal life near the sites may be disrupted due to activity associated with construction, operation and maintenance. Development sites are relatively small in area and it is expected that disturbance of animals would only be in terms of a minor relocation rather than as a_ threat to their existence. Vegetation: A slight decrease in wind speed and and increase in soil moisture and plant vigor near the turbine may result from machine operations. Protective measures may be required to halt possible erosion resulting from the loss of ground cover or degredation of the tundra near the base of the tower due to the movement of vehicles and personnel. Socio-Economic: The following socio-economic parameters should be considered: demography, land use, local economy, historical and cultural factors, communications, noise, and visual quality. The most sensitive areas are: Communications: Large horizontal-axis wind turbine rotors can cause interference with high frequency radio propagation in some locations. The signals which may be affected are in the FM radio, television and microwave frequencies at reception points where geometries favorable for interference occur among the wind turbine, transmitter, and receiver. The incidence and severity of this interference will depend mainly on the distances between the transmitter, windgenerator, and receiver; strength and frequency of the signal; character of the antenna; and blade speed and scattering area. Careful siting of the turbine can mitigate most of the problems that may occur. Proper selection of blade materials and rotor design can also lessen the degree of reflection. Noise: Noise levels associated with the operation of large horizontal axis wind turbines are insignificant. Noise monitoring studies of the 100kW MOD-O at the NASA Plum Brook site indicate that a slight gear noise and the sound of wind passing over the blades are not audible above the natural wind at distances greater than 400 feet from the turbine tower. However, experience with the MOD-1 turbine at Boone, North Carolina (which has 61m blades) has shown that the wrong blade design sited without forethought to sound 6.1.4 Safety transmission, can cause some problems. The slowly oscillating blades at Boone produce low frequency (1 to 20 Hertz) inaudible sound waves, called infra- sound which magnify in an eardrum effect through the valley. The blades are being redesigned and a new site looked for to mitigate the infrasound problem. Visual Quality: Visual impact can be influenced by the public's attitude toward the concept of obtaining energy from the wind. DOE experience with their MOD-OA and MOD-1 units. has been favorable. At most of the proposed sites, the wind energy project has been enthusiastically supported by the public as well as local andstate officials. These earlier machines are considered aesthetically acceptable to most viewers and in some cases are considered a tourist attraction. On the other hand, some viewers will find any wind turbine unattractive. Although wind turbine components have been designed to withstand severe wind conditions (in excess of 150 mph), there exists a slight danger that a wind turbine blade might fail or that the wind turbine tower might collapse due to severe wind loading or other extreme environmental conditions. To minimize risks posed by blade or tower failure, reliable safety features have been engineered into wind turbines and are being accomplished by the institution of strict safety precautions and procedures. Previous studies by DOE with the MOD-OA and MOD-1 systems and the MOD-2 program have analyzed safety concerns for structural failure of the tower or blades and other hazards associated with tall rotating structures and electrical equipment. As a result, reliable safety features have been engineered into the MOD-2 wind turbine. For example, an early crack detection system has been incorporated into the MOD-2 blades so that if a crack begins to develop, the machine will automatically shut-down hundreds of hours before serious damage occurs. In addition, strict safety precautions and procedures are to be instituted by the responsible utility. (a) General Safety Precautions and Procedures: The tower structure and blades should be inspected at regular intervals: by the utidity or’ -T€e"s contractors to identify and repair potential structural defects. The turbine should also be inspected immediately following severe wind or other conditions, such as earthquakes. A limited radius of about 175 feet (53.3 meters) has been maintained around the MOD-OA turbine. Visitor access to the restricted use area would be controlled according to procedures detailed ina visitor control plan developed by the utility. Technical personnel should be thoroughly trained to follow safe operating procedures and should be fully informed of risks associated with the wind turbine's electrical equipment, rotating machinery, and any cable hoist. Wind turbines should be designed to fully incorporate OSHA safety regulations and specifications. (b) Categories of Risk: Four categories of risk have been identified for a large, horizontal-axis wind turbine: (1) tower collapse or component blow-off; (2) blade failure; (3) injury due to unauthorized access; and (4) collision by low-flying aircraft. These are defined below, together with factors which would precipitate or limit the risk mode. (1) Tower Collapse or Component Blow-off: In the event of tower collapse or component blow-off, the wind turbine or component may fall in any direction. Maximum horizontal extension of the turbine, if a 91 meter rotor retained its integrity, would be 165 feet. Since the rotor would be feathered and braked far in advance of the occurrence of wind speeds exceeding tower design limits (in excess of 150 mph), blade throw is not expected to accompany tower collapse. However, the rotor may break due to striking the tower or the ground and may therefore increase the area of impact, depending upon the orientation of the rotor and the attitude of tower collapse. Degree of risk - Tower collapse is considered highly unlikely, even during periods of extreme wind. The only conditions which are viewed as potentially hazardous are tornadoes or freak gusts which exceed design limits. Other possible causes of tower collapse include foundation undermining due to ground settling or a sudden geologic calamity such as an earthquake. Foundation undermining would be a relatively gradual process and would be noted and corrected during regular maintenance and inspection activities. Ground acceleration forces associated with a nearby earthquake of up to 7 on the Richter scale are less than those associated with high wind loading and are not a significant danger with structures of this type, although some risk cannot be discounted. The risk to technical personnel or visitors near the wind turbine is not expected to be high in the event of tower collapse or component blow-off due to the severity of conditions which would precipitate the failure. It:. is unlikely that people would be in exposed areas near the turbine during periods when winds approach or exceed 120 mph. During an earthquake, the turbine would pose less risk than many other structures due to its high structural integrity, relatively low mass, and the absence of loosely attached overhangs or facades. (2) Blade Failure: Computations performed by NASA Lewis Research Center indicate that an unrestrained MOD-OA wind turbine blade could be propelled up to 550 feet from the tower base if it broke away from the hub at 40 rpm and at optimum blade throw angle. Blade throw distance would be significantly reduced if shedding occurred at less than optimum blade angle. Safety features and precautions have been instituted to identify structural problems and decrease the risk of blade failure due to the uncertainties regarding blade loading experienced by the early machines. A wind turbine system could be equipped with automatically monitored sensors that would shut down the turbines for an unusual load as signalled by excessive vibrations or dynamic imbalance. Remote or automatic restart would not be possible, and the turbine would only be restarted by resetting the system at the site. Degree of risk - Given the safety and design features incorporated into modern wind turbines, blade failure is highly unlikely. Two additional factors limit the potential for injury of people within the limited-use area: (a) Most turbines will not be rotating when wind speeds exceed 40 mph. (b) It is not probable that people (particularly visitors) will be in exposed areas within or near the exclusion radius during high wind or storm conditions. (3) Injury due to Unauthorized Access: Safety risks associated with unauthorized access to the wind turbine include falls from the tower and injury caused by coming into contact with power equipment near the turbine. To discourage climbing of the tower, care should be taken to eliminate provisions for footholds which would allow its to be scaled easily. All hoist controls should be securely sealed to prevent tampering. In addition, all ground level electrical equipment should be shielded and/or caged in compliance with OSHA specifications and regulations. 10 (4) Low-Flying Aircraft: If sited out of the clear zone of a runway and outside the regular traffic lanes, a windgenerator will poise a limited hazard to aircraft. FAA requires a installation of an obstruction light on any tower approaching 200 feet. These measures should serve to reduce the risk of aircraft/turbine collisions to safe levels. 11 6.2 Regulatory Restraints Legal and statuatory constraints for a wind system are extremely site and machine specific. Zoning ordinances are practically non-existent in the study areas. However, native allotments, parks and reserves will require extensive research into land use parameters. Limitations on height are expected to be centered around FAA airport regulations. The National Environmental Policy Act reporting requirements for large windgenerators have been limited to a brief environmental report and a statement of no significant impact. Historical or Archeological sites should not be impacted by law. The endangered species list should be consulted to avoid any possible impacts in the siting of the turbines. The coastal zone management plan should be consulted if the machines are sited within the coastal bounds. 6.3 Regional Restraints An extremely important regional restraint is the short construction season which is complicated by the fishing season that overlaps it. The socio-political make-up of the region is unique and should be factored into any major development program. The land ownership constraints need to be put into a regional context. 12 6.4 Conclusions and Recommendations Few of the restraints identified in this section are likely to be troublesome with respect to feasibility. Careful siting and good planning will mitigate most anticipated impacts. By power company standards windgenerators are relatively benign. Most of the impacts discussed are not even relevant to wind turbines smaller than 25 meters. We anticipate the majority of installation in the Bristol Bay area to be in the under 25 meter category. Utilities should of course be sensitive towards the issues raised in this analysis - especially the publics attitude towards windgenerators. 13 ‘. FACILITY SCHEDULE This section defines "commer- cial readiness" of windgenerators for Bristol Bay with a chart showing the number of units built and the year that. a particular turbine size. is ready for utility use. Based on this chart, a medium-sized turbine is selected to develop a facility schedule. The phases for the program outlined are: Design Development, Assembly and Testing, Site Prepara- tion/Construction, and Training/Data Collection/Transition. 7.1 Introduction In developing a facility schedule for a typical wind power generation site, a large number of assumptions and generalizations need to be made. In our example, we have assumed that an easily accessible site is available. King Salmon, Naknek, or Dillingham would be typical locations that would meet the above assumption. We have also assumed that a 17 meter to 25 meter turbine is to be installed. 7.2 Commercial Availability The DOE has defined "commercial availability" in their wind program development very loosely. If a manufacturer had built three windgenerators, sold one, and had one operational, it was a "commercially available" turbine under DOE guidelines. For purposes of this study we are defining "commercial readiness" for the Alaskan Market differently. The remoteness and extreme environmental conditions require a substantially more developed machine than in most other locations. It is our opinion that until a large number of windgenerators in a size range are built and installed they should not be considered for a utility application. Unfortunately for both the consumer and manufacturers, there is not presently a strong well established trade organization in the wind industry. In other industries figures on number of units manufactured, installed, and number of hours of operation are readily available through a trade organization. Because of the lack of maturity of the wind industry as a whole, production information is considered proprietary and not released. We estimate that there are at least 1,000 of the 4 meter size turbines manufactured to date and that as a class it has achieved commercial readiness for Bristol Bay. Based on the approximately 400 machines in the 7 meter category, another year is needed to work the bugs out before introduction can be made into this state on anything but a demonstration basis. The following chart was prepared to establish our best guess on commercial availability based on the number of units manufactured for the size categories studied. The exact date of maturity for the turbines is dependent on successful demonstration and manufacturing production. Both the demonstration projects and the production capabilities are ‘variables the state can alter through a comprehensive wind program. The economy and energy prices will effect this graph dramatically as well; they are totally out of the state's control. FIGURE 7.1; ANTICIPATED DATE OF WIND GENERATOR COMMERCIAL READINESS FOR BRISTOL BAY USE 1250 4 Meter Turbine - ° °o ° 500 7 Meter Turbine 10 Meter Turbine 17 Meter Turbine Nn a NUMBER OF UNITS MANUFACTURED 25 Meter Turbine 91 Meter Turbine 198081 82 83 84 85 86 87 88 89 1990 YEAR 7.3 Facility Schedule 7.3.1 Design Development The first phase starts with a detailed assessment and site selection process. This comprehensive planning step should identify all the participants in the project and elicit their involvement. The equipment manufacturer would be identified in the schematic design phase and long lead items identified. Community meetings would be held before final design is initiated. Working drawings and design development completion would then follow through to final design. 7.3.2 Long Lead Time The second phase begins as soon as the long lead items can be identified during the design process. Material take- off and procurement would start when final design is initiated and any items that require barging would be expedited. Logistic problems would be worked out in this phase as well as preliminary site preparation and equipment mobilization. 7.3.3 Assembly & Test The windgenerator components would be tested separately at the point of manufacture and then shipped to a test bed in the lower 48 for assembly and check-out. This step is intended to solve most of the hardware problems before the machines reach Bristol Bay. 7.3.4 Site Preparation/Construction Beginning early in the construction season, the site staging area would be prepared. Having the proper tools, equipment, and materials on-site is crucial to completing the project in a single season. The construction should proceed with as much local involvement and cooperation as possible. Upon completion of the installation the turbine will go through testing and start-up shakedown. 7.3.5 Training/Data Collection /Transition This final phase would begin with a concerted training program to teach the local operators how the system works and how to maintain it. The training program could be coordinated with the local community Voc-Tech center so that an ongoing program can be established which is in-line with the needs of the community. This phase is also a transition period which gradually over a period of-months turns the system over to the local utility. The data collection could be phased into a statewide information network so other utilities could benefit from the experience. FIGURE 7.2 OCT | NOV ns Training etc. Installation Start a Ww no S 2 <= = 2 > z > > Mat'ls Take-off, Procurement, MAY | te Prep | ime S ime | APR MAR YY YW) YY YYyj gram t Long Lead T Yy J | JAN | FEB | Development Total Pro oO WwW a 8. ECONOMIC ANALYSIS @ 8.1 Installed Costs The cost information developed for this section was based on installed costs in the lower 48. The information was from actual installations and represents in most cases an average value using 1981 dollars. Prices are turnkey costs with construction being performed within a single year time frame. Cost of engineering, turbine, controls, tower, foundation and wiring are included. To estimate Bristol Bay costs an Alaskan construction cost index was used. A large village scenario was chosen and an index of 1.69* selected as roughly representative. FIGURE 6.1 COST COMPARISON BY SWEPT AREA Turbine Lower 48 Bristol Bay Swept Area $/Swept diameter Cost Cost Area 4m $10,000 $16,900 13m? $1300 7m $22,000 $37,200 38m2 $1000 10m $34,000 $57,500 80m2 $700 17m $100,000 $169,000 227m $700 28m $380,000 $642,200 490m2 $1300 91m $6,000,000 $10,140,000 6500m2 $1500 @ *Source: HSM, INC. - Anchorage, Alaska These costs represent a broad spectrum of possible installations. The 10-17 meter size range is the most cost effective turbine based on this analysis. There are a number of factors which contribute to the variability in installed cost estimates. The first is the price of the hardware itself. The lack of mass production and a true price competitive market make the cost for the turbines high. The larger the turbine, the more handmade they become, so that any economies of size that should hold true are not found. Additionally, when the jump is made from the 17 meter to the 28 meter size the type of generator goes from simple induction to a synchronous generator. The power from a synchronous type generator, as discussed earlier in this report, has more value to a utility than an inductive machine. 8.2 Power Production Cost Comparison Using some gross parameters for purposes of estimating relative power production costs the machines can be compared. The following assumptions are made to allow a straightforward analysis of the different turbines. A typical good wind site for Bristol Bay would have a high wind power density (King Salmon area is class 5). Assumptions: Wind Power Class - 5 Economic Life - 15 years O & M Costs - not considered Rate of Return - 0% (for comparison only) Amortization method - straight line FIGURE 6.2 POWER PRODUCTION COST COMPARISON Turbine Annual Energy Output Installed $/MWH* diameter Power Class 5 Cost 4m 10 MWH/yr $16,900 113 7m 37 MWH/yr $37,200 67 10m 60 MWH/yr $57,500 64 17m 220 MWH/yr $169,000 51 28m 580 MWH/yr $642,200 74 91m 9,000 MWH/yr $10,140,000 715 *These costs are for comparison only - actual utility costs would be much higher. This analysis does not include costs of operating a utility such as insurance, taxes, billing, management, land, debt service, operation and maintenance. Operation and maintenance costs are usually estimated at 1% to 5% of installed costs for a windgenerator. Much more operating experience is needed before these numbers can be accurately estimated for Bristol Bay. 8.3 Conclusions and Recommendations Before a utility could begin to estimate the cost of a wind power program, very site specific information would need to be developed. Once a program has been established, economics can be developed from multiple turbine installations using the same crew. Labor and transportation are the biggest unknowns for bush windgenerator construction estimating. A phased introduction of windgenerators is the most prudent approach to successful utilization of wind energy. As the larger machines mature and are proven through demonstration projects in Alaska they can then be added incrementally to a grid. This would allow a utility to learn operation and maintenance costs before fully committing large capital expenditures. APPENDIX A Wind Data FIGURE A.1 MONTHLY DIURNAL VARIATION-KING SALMON Legend 3s T T Wind speed/diurnal variation T + res 2 + { Zas + } ; z « se $2 Zis { foe > ; | LF z | Pe j tba i ry s f | ly | | ’ “ty” { eee lt Omt 00 oo oe ow n ss w n oO aL t+ Number of observations Mean wind speed (knots) by hour (GMT ond Locol Time) ond for oll hours 4 | = -|—~-(the ease wind speed fer the howe 21 GMT (16 tocol) wos 20 knot.) BLACK LINE - Scolor mean wind (knots) tocatie F 22 on $26 08s, a en Time Map - Scalar mean wind ~ In areas of high persistence of direction, the magnitude of the vector mean winds should closely approach thot of the scalar mean winds. As most of the marine observations ore recorded ot six hour intervals, disregard the plots for other thon 00, 06, 12, 18, GMT hours on the marine area graphs * neom WIM SPEED tmm@TS 3 5 : a ® King Salmon February King Salmon HIND SPECO-O1 yam vamiar jon simp SPECD-O1URNA vamiat jon gy os * eam WIM SPEED LAMOIS! wimg SPEED (aMOIS) 3s — 2 5 :" i ® 3 + mean September King Salmon King Salmon s usp Sree yaniatjon s | | i i i i | | 3 EAN WIND SPEED 1aNOIS! 5 z a z onr_—00 oy 08 0812 corm. 1@ 17 20023? 6445 08s. time November December FIGURE A.2 INTERANNUAL WIND POWER AND SPEED ++ WIND POWER LEFT ORDINATE - WATTS/M? «----+ WIND SPEED RIGHT ORDINATE ~ M/S rm 3188 wennse ABSCISSA — YEAR V AND P ADJUSTED FROM Z TO 10 M BY 1/7 POWER LAW ee nee KING SALMON AK ILIAMNA_ AK ; CAPE NEWENHAM AK 25623 3005 7 +6 200 5 4 100 “Fs “2 ° t tT 1 40 44 48 52 56 60 64 68 72 76 80 FIGURE A.3 MONTHLY AVERAGE WIND POWER AND SPEED | —— WIND POWER LEFT ORDINATE — WATTS/M* sereeee WIND SPEED RIGHT ORDINATE - M/S ee ABSCISSA — MONTH V AND P ADJUSTED FROM Z TO 10 M BY 1/7 POWER LAW KING SALMON AK 02/62-12/78 TLLAMNA an wa larpe fee, CAPE. NEWENHAM AK o4/si-12/70 8 = Es ~88a8 oEBEE ¢ $8 8 § JFMAMIJIJASOND JFMAMJJASOND JFMAMJJASOND FIGURE A.4 DIURNAL WIND SPEED BY SEASON +——+ WINTER ¢----~SPRING ORDINATE — M/S @- —-® SUMMER #®~--®AUTUMN ABSCISSA — HOUR PNL-3195 WERA-10 KING SALMON AK 02/62-12 ILIAMNA AK 0748—09/64 CAPE NEWENHAM AK 04/61-12/70 25503 Z= 61 G. V= 48 P= 1 25506 Z= 98 R V= 46, P= 151 25623 Z= 40 G, V= Sl, P= 242E Paes 104-~ 10 eed i Seer nae oN * @ @ one Oo @ o 3 6 9 12 15 18 2 2 FIGURE A.6 DIRECTIONAL FREQUENCY AND AVERAGE WIND SPEED —— PERCENT FREQUENCY LEFT ORDINATE — PERCENT secceee WIND SPEED RIGHT ORDINATE — M/S Pan. 3198 WERA10 ABSCISSA — WIND DIRECTION KING SALMON AK 02/62-12/78 ILLAMNA AK 0748-00/64 CAPE NEWENHAM AK 04/61-12/70 25503 Z= 61 G, V= 48 P= I 25506 Z= 98 R V= 486, P= 151 25623 Z= 40 G. V= 51. P= 242E 40 12 40 2 40 12 x2 9 30 9 a 6 20 6 10 3 10 toed x ° ° 0 ° N NE E SE S SW W NW N NE E SE S SW W NW N NE E SE S SW W NW FIGURE A.6 ANNUAL AVERAGE WIND SPEED FREQUENCY —— ACTUAL DISTRIBUTION ORDINATE — PERCENT apne RAYLEIGH DISTRIBUTION ABSCISSA — M/S PNL-3195 WERA.10 KING SALMON _ AK 02/62-12/ ILLAMNA AK Oo 64 CAPE NEWENHAM AK 04/61-12, 25503 Z= 61 G. V= 48 P= 1 P= 151 25623 Z= 40 G, V= 51. P= o 24 6 8 0 12 4 16 FIGURE A.7 ANNUAL AVERAGE WIND SPEED DURATION ORDINATE — PERCENT ABSCISSA - M/S PNL 3198 WERA.10 ha ILIAMNA AK 07 ‘64 CAPE NEWENHAM AK 04/61-12/70 ee Gere pena ye 25506 Z= 98 R. V= 46, P= ¥g 25623 Z= 40G, V= tfc 242E MOE ee 100: - 100 Feepr rer eyery oi: Tan 80 80 80 60 4 60 60 40 40 40 20 2 20 ° - ° °o o 24 6 8 00 12 4 16 024 6 86 © 2 4 6B o 7 4 6 8 10 12 14 16 FIGURE A.8 ANNUAL AVERAGE ORDINATE — PERCENT ABSCISSA — WATTS/M? PNL-3195 WERA-10 KING SALMON AK 02/62-12/78 25503 Z= 61 G, V= 48 P= I 100 0 20 400 600 800 1000 WIND POWER DURATION ILIAMNA AK 0748-09/64 25506 Z= 98 R V= 46, P= 151 oS 8 8B8 0 200 400 600 800 CAPE NEWENHAM AK 04/61-12, 100 25623 Z= 4.0 G, V= 51, P= 24) Wea “rr PERCENTAGE FREQUENCY OF WINO ; Wee 1%~5FP 1 DIRECTION ANO SPEED (FROM HOURLY OBSERVATIONS) gurnneR ELES LL ELE 12-21 | 22-23 | 29-33] 34-40] 41-49 vt-ar| ve % mine oho] IG i a. Ol a acyl 556, 2 YAS p10 elo TOTAL No. OF OBSERVATIONS 6Y3 JQWWNS B1eq PUIN ABg UINIG 4, suo PERCENTAGE FREQUENCY OF WIND » Gray DIRECTION AND SPEED > YD (FROM HOURLY OBSERVATIONS) : Fr SPEED. ae “ 22-23 | 23-33 oe | i-3 | 4-6 | #-10 | t-te ] 17-21 34-40] yi-uz | us-se | 256 |] % N ve | @ TH OD NE im aD er | a A i al CO PD PAT Gy LRT 7) ese | O T MTe® | SE ai Gy oy "Wes SSE ry Weil oD “yi Oo” oe ero saa repr . Sw [AAT Gy PSS ii l Wsial TTD TATTG Sy ym @ T | w Nee ia Larrea LCE x31 wan fF Faia oO Nw PRT LAT Ey "@ naw [f™ CO [Tap VARSL Tay DD pH 7 - Ze canes | 9 Yih 21eq puln Aeg ulnig A cefedls | Cel xea zal Lar | H40 445 N23 YOU 4239 9960 193% G27? /0%0 ng. TOTAL No. OF OBSERVATIONS 123 apron tong and oR. PEQCENTAGE FREQUENCY OF WINO DIRECTION ANQ SPEED CFROM HOURLY OBSERVATIONS) 1F#-21 22-27 2% - 33 ——-- 7. 34-4] G1-4F | 48-55 | 256 MEAN wind SPEED NNS NE Ene wna) g?, “al oO oY Lo ue E ESE se SSE ssw : SW Wsw Ww wey NW NNW _VAROL CALM +E “4B 3,0 Yo) yen. 6 8,8 FOO Yos TOTAL No. OF OBSERVATIONS JOIN ejeq puly Aeg uinig or PERCENTAGE FREQUENCY OF WINO DIRECTION ANOQ SPEED (FROM HOURLY OBSERVATIONS) F-10 | U-tG [1F-21 23-33 | 34-40 NNW VARSL + cALM [A RTTOTER TNE TOTAL No. OF OBSERVATIONS —_—_—_____ Ss - Bud e1eg pulpy, Aeg uinig tb CAPE NEWENHAM ALASKA AFS 53-70 ALL STATION NAME YEARS MONTH ALL WEATHER ALL CLASS HOURS (L.S.T.) SPEED MEAN. (KNTS) 1-3 4-6 7-10 1-16 17-21 22-27 28 - 33 34 - 40 41-47 48-55 256 % WIND DIR. SPEED 2.8 ll. 11,0 NNE 4 8 9 26 el 0 20 0 eae 8.2 NE e3 45 «6 3 a: 20 i) 20 V. ENE 2 A} 6 6 y 4 el 0 20 0 20 toe 10,8 E 24 9 1.4 14 +6 «4 os ol 70 ae Ri 5,2 12.6 ESE 78 PC Tae Be Uy i ed “7 3 el 20 +0 20 6.3 |13. SE os 9 Tut 2.5 1.5 1.0 <o 2 00 20 8.6 [14.9 SSE 24 1.2 1.8 2.4 | 1.1 06 0% ol i) 20 7.7 [12.6 s a We a ee 4 ol 20 9.8 [tt ssw el 6 | 1.3 | 1,3 04 ol 20 20 3.8 [10.8 SW. el 26 1.1 28 © 0 20 20 Ze 9.4 wsw oi 04 28 5 el 0 20 1.9 5.5 w +2 7 | 4.3 9 el “tT .0 3.3 | 9.4 WNW 2 23 1.1 1.0 73 el 20 20 wee 10,6 NW 4 9.1 1.7 1.8 6 2 0 0 5.9 [10,6 NNW 24 Lt 1.7 202 1.1 of on 60 Wipe 11.9 VARBL CALM J 5.1 114.4 |22.6 | 24.7 [10.2 | 4.7 1.4 5 ol 20 «0 (100.0 | 9.8 TOTAL NUMBER OF OBSERVATIONS 1308 3 4 Oly 3YNDdId e1eqg PUI, WeYyUsMOEN eden AMNUAL Wied SutARWIRY UNITES? LOCATI/OI Dibinenng MRE MOMETER = YOT3REFD LDEMIFIER! LEO | NUMBER’. PERIOD OF RECORD Tue Pon— run 97 orTH [sane (53 ee ie a oll feline 3235 37 ar 33/344 Vel VEST SES Wane | Rae) Hea QBS | DIR |SPEFS les [a3 laa soles lgalll tule fees ra ut) 2.8 | /6.0|s.a)%.4 | fet eae = npr ial a [oy idle Se PT owlewel |S = i 7 fe 7 ae eel ee que aah fee eels lel Sa a 1 a: [rue lar tno fas.0l4cloe pxlec| | A pur lpg aft nad —_ — aoe a hea oleamoe bab A) aed eee or ED 0 alsgvienelealacl Pt aed 3 Gasol 127 |380 lane] 29 |0. 810 ea cen Peau 241.424 air |8.0\ 1) lo. er eat aoa ee Le Annual 7.0 i a 1AG.0| 7D 116 [of et tiv aundid eb STATION (LI AMNA a « 25800: FROM wEN701 TO ewO970 QNEMOMETER HEIGHT 9 8 METERS PEFEREMCE POCF TOP AVEPAGE We NOD SPELO *M/“SEC) Bs HOUR AND MomTH NUPBEP OF UPLID OBSEPATIONS Iw 2ce9 wOUr monte Gc OF OF OF O8 OS Be OF O8 C9 10 GH 12 12 B64 15 Be 17 B2 99 SO Zh 22 3 we SES FHL PH BV TH FH SHIH IHFIHLISOSOSOV AHHH SH OH DH OE HEBEL OED Sys 5 © $955: 5 6 © 5.9 7 aa 7 © bY EH EH THEY EHHHHEH HHS HSH SHES Owe 2 sie Tee vee Su SH Seuuse e ThE SOC Se Oey SS ESN Le Soe cit eS . TEITESSOIEISTSEIBISv is: 3497022981598 9N8F008393F 30386 > s 2S 2S ZA TSS 8 SOIR Ie SOS ISESSSS7S7SCS FE CSI Tl 39TH ee e PTISIOIHIIISI7FII9VSeSv IS ZSESSrSrSUSFESESISOVHL 9 73748 > 3S 24 FPHFTOSO SOS IS wISVC Oe 34S ee 6 SS GE IF 14 OD KOu.3 83:6 2:2-320.99 & TP Jos PIF oesyersrZIoIIv2uSurugFSOS2S>S$rSOurvurveoazsezsazsre: 9. PU LEVO LEDS SEAMS PR TEAS ZETEC SESS TL Be Tere te se sels 1O vr HF eB rarer a7 H7HH9SISISHSSSHSOSHSONEY TH PUB Ew BH SG5D Mt SSSSCESSEISISSSEASISGAIS SS ASSESS eS Sh 36518 LS 625 Zeus 557262 low FH eH THT HT HOH TH BHBFEOSHSOSCSISOSON OVEN EHC EH BOON SH SHB COR STULL HSHSULYOTSSH Te SoSussOsrSscS2STIEANV Se Pv Euus Furu sue AVEPAGE WIND SPI *M/SEC® BY SLASH N HEIGHT MINTER spe SUAAE® AUTURN rinse. 8 “8 “2 ? “eo 100 “8 wc “9 Ye soo eo $3 e: se PYERAGE WIND POWER IWATTS/ME8>) BY HOUR AMO MONTH NUMBER OF VALID OBSEFATIONS 14271 our monTH = 00-01-02 03 OW 08 09 10 11 12 23 14 18 te 17 1 174 189 194 192 182 183 is 225 S26 213 186 202 2 1H 173 173 104 169 tow 171 ; 170 181 158 fe 171 3 18° i> 195 207 278 198 177 Vee 182 6 it Ve 148 144 1 182 162 186 12 tae 5 8 oe 110 139 197 179 tow 98 1ib © 7S bs 103 142 184 173 162 82112 . he e 128 122 4ot e> & & 89 % 1 165 148 135 $2110 6 ii 1491 175 tet 159 122 tee 10 tes 6b 1 200 205 171 176 195 179 " 206 1791 207 266 210 197 192 199 te 1S> a8. 1 1e9 229 1o4 16F 169 166 68 120 144 186 18 188 17% 104 ii tt AVERAGE WING PCHEP (WATTS Meaz) By SEASON HEIGHT WINTER SPRING SUMMED © AUTUMN ANAL, +5 179 ise 102 1 181 9 Q ver ise 103 1 3 Zet 206 205 + 81 Ziv ayndia 2}eq Pulm BUWellll bE KING SALMON AFS AK 67-10,73-79 ALL STATION MAME YEARS MONTH ALL WEATHER ALL cuss moURS (L.8.T.) ‘CONDITION SPEED J MEAN (KNTS) 1-3 4-6 7-10 W- 16 17-21 22-27 28 - 33 34-40 41-47 48-55 256 % ‘WIND DIR. SPEED N °8| 3-6| 4-8] 3.3 -4 a1 13.0| 8.7 NNE 6 2.8 1.8 1.0 +2 20 0 5.6 7.8 NE ~6{ 1-4[ 1.0 76 72 el A) ~O {3-9| @.1 ENE 77 ee ee: &) 3 pi 70 { : 4.4| 8.5 E ai 229) |muee9 3.6 let Tel a ot 20 12-4| 12. Ese -A[ 1.2] 1-2 ay 72 [60 +0 3.9] 8- SE +A lea 1.2 ay aS iz il ee. -o | 4a] 9-6 SSE sO D nes uals 1.6 79] |e at 0 | ae 10.7 s -5{ 1.8{ 2.6] 2.2 7 2 0 0] 8-8] 9.9 ssw a} 1.4 2.6 1.6 02 -0 0 0 | 8-1 | 8.9 sw 3 1.0]. 194 1.2 az -0 +0 qT 4-1{[ 9.3 wsw 4 «9 1-2 1.1 aa ol 70 [ 3.9| 9.5 w ne 1.3 1.6| 1.3 as, al i) 5e1| 9.0 WNW 3 9 8 4 el 20 6 Za 7.5 NW ~3[ 1.0 “9 Alo 20 .a L | | i NNW Bi 74| Mote 51 ci7d [LIS a .0 -0 7.5] 6.0 VARBL 2D «0 9.0 CALM 561 a £ 8.0} 25.9| 29.6} 22.2 6.1 2.4 -5 el 0 100.0 8.9 os TOTAL NUMBER OF OBSERVATIONS 87 592 ety ayundia 2}eq Pulm UOW|es Buy st 1390 STATION PILOT POINT, ALASKA 3 Obs, Daily. : PERIOD SUMMARY BY COMBINED VELOCITY GROUPS DEC. 1938 = WHOMEK ANNUAL PERIOO spn, 1941 abl ee id Lal al ale ts viv aYHNdI4 BYE PUIM 4UlOd 10|Ild Platinum Wind Data FIGURE A.15 =a Ziel cal cc clea ~ | ews Imietead eee aa (ae ee cS EF anna Tease ae Mudewe eden dane Ieee dies Tue ea cs ee ede aa dN TDA a ee cc) a ots Men eh CM ee a eo SdMOEs Se ae Ce eee CMU SRN Ere TORR rat g 4 Piece Re ks es i 16 at PORT HEIDEN ALASKA APT 42-45 547-51 ALL STATION NAME YEARS WORTH ALL WEATHER ALL class wouns (L.8.7.) ‘CONDITION SPEED (KNTS) DIR. 3S oo A) len “fates -fel- a _t S| SO H| N/ G) oO] HO: > je |e be |e is |e jo le jo jm |e jo fo [OD Jaf | 0 Jo | | Je | ON/AD) |r| Un] WO le Pe et [> DP} DB] Si a} oy ww) ~ lo le |e le |e je |e le je |e le YO] J] ) WD) H] ad) “t i TOTAL NUMBER OF OBSERVATIONS 58085 ot'v AYNDIS B}eQ PUIM USPIa}H Od st 1390 3 Observations Veily. PERIOD SUMMARY BY COMBINED VELOCITY GROUPS MAY 1939 - STATION TANALIAN POINT, ALASKA MRE arcmar PERIOD Ti) IR, ‘ way N INNEINE |ENE] E [ESE|SE|SSE| S [SSwjSw Ww Nw ie 4-15 2 60 4/0 7 / 19 \72 | 67 47 we NA ean SAA EL I eve 32-47 y 3 |4 OVER FT 47 Ue CALM eae | TOT. + oes, 70 / 00 6 6 375 CALM aL/ STH MSA PV ee be el bea tie div aYNdIS 2}eq PUIM JUlOd ueleUeL FIGURE A.18 ALASKA POWER ADMINISTRATION MONITORING PROGRAM RECEIVED oe, 2 & 1981 Department Of Energy Alaska Power Administration ALASKA POWER AUTHORITY P.O. Box 50 Juneau, Alaska 99802 August 25, 1981 Mr. Eric Yould Executive Director Alaska Power Authority 333 West 4th Ave., Suite 31 Anchorage, Alaska 99501 Dear Mr. Yould: We wanted to bring you up to date on our wind power investigations for the Bristol Bay area. We have contracted with AeroVironment, Inc. of Pasadena, California, to perform wind energy monitoring and appraisal analysis for potential wind farms in the Naknek-King Salmon and Dillingham areas of Bristol Bay. In this appraisal analysis, the contractor will (1) review miscellaneous available wind data and obtain, reduce, and evaluate existing recorded data to determine sites to be monitored; (2) furnish, install, operate and maintain monitoring equipment, and utilize the assistance of two local utilities to operate and maintain the equipment; (3) evaluate data obtained from the monitoring and prepare an appraisal estimate of the wind power generation potential to supplement the present utility systems, including preparation of conceptual wind farm layouts, cost estimates, and operation characteristics; (4) recommend a scope of work for subsequent monitoring and analysis to result in a feasibility level evaluation of a utility operated wind farm system; and (5) recommend a location and criteria for possible installation of single SWECS generator. . The two utilities, Naknek Electric Association and Nushagak Electric Cooperative, will assist with site selection, instrumentation installation, data retrieval, and instrument checking. APA will perform economic and cost analyses. 19 The schedule is: Monitoring site selection and instrumentation 8/30/81--9/05/81 (approx.) Monitoring equipment fully operational and beginning of data 10/01/81 Status Report (draft not to be final) 4/15/82 End data collection for analysis, but continue data collection 9/30/82 AV draft report to APA 11/15/82 End data collection, restore sites, public meetings in Bristol Bay 11/30/82 (approx.) APA comments to AV 12/13/82 AV final report to APA 1/15/83 Sincerely, Ez. J. Gi i Administrator 20 APPENDIX B Bristol Bay Wind Generators FIGURE B.1 WIND GENERATORS IN THE BRISTOL BAY AREA (1) (2) (3) (4) (5) (6) C7} (8) (9) (10) (2:1) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) A A A A A A = O A A 4a 4 bDDPPPDRDPPRPRPRP PPP vp a Installed & Operating (year installed) Installed-Not Operational (year installed) Presently Not in Use (year installed) System Planned and/or Purchased (year to be installed) Afognak Island, 2kw Aeropower, Battery Charger (1981) Chignik, 2kw Aeropower, Battery Charger (1981) Dillingham, 10kw Jacobs, Utility Intertie (1981) Dillingham, 300 watt Aerowatt, Battery Charger (1974) Dillingham, 200 watt Wincharger, Battery Charger (1960's) Egegik, 4kw Enertech, Utility Intertie (1982) False Pass, 2kw Dunlite, Battery Charger (1977) Fox Bay, 1.8kw Jacobs, Battery Charger (1978) Illiamna, 2kw Jacobs/Dakota, Battery Charger (1979) Illiamna, 2kw Jacobs, Battery Charger (1979) King Salmon, 4kw Enertech, Utility Intertie (1982) King Salmon, 300 watt Aerowatt, Battery Charger (1975) King Salmon, 2.2kw Enertech, Utility Intertie (1979) King Salmon, 2.2kw Enertech, Utility Intertie (1981) Kodiak, 1.5kw Aeropower, Battery Charger (1981) Kodiak, 10kw Jacobs, Utility Intertie (1981) Lake Clark, 3kw Jacobs, Battery Charger (1977) Nikolski, 2kw Aeropower, DC motor, lights & heat (1980) Naknek, 2.2kw Enertech, Utility Intertie (1980) Naknek, 10kw Jacobs, Utility Intertie (1981) Nelson Lagoon, 20kw Grumman, Utility Intertie (1977) Nelson Lagoon, 15kw Grumman, Utility Intertie (1981) Newhallen, 8kw Stormmaster, Battery Charger (1980) Port Alsworth, 2kw Jacobs, Battery Charger (1978) Port Heiden, 2kw Aeropower, Battery Charger (1981) _.FIGURE B.2 DILLINGHAM WIND INFORMATION in OF TCGHA _ P.O. BOX 191 - : DILLINGHAM, ALASKA 99576 ~ TELEPHONE (o07) 842: pet or 842 212° Bob Costello 224 26th N.W. ~ Peay ’ Olympia; Wa 98502 |. : Dear Mr. Costello: ones! a Your letter was forwarded’ to me at the City a Dillingham, 80 7 will cit _ and answer ‘most of your ee one ata saat : : + ves af Type of Wind Turbine?’ All ‘I can a give you is the ‘wake which: is an~ ' Automatic. Power Inc. Turbine. . They are a division of Pennwalt, Corporation located at 213 Hutchesen St., Houston, Texas... I.think if: ou: ould’ write- to them they could give S dace more exact eat : vee 2. Our Wind Generator de mounted ‘én’ a section: ‘of 6" st el pipe. about ; 15' long, 5' in the ground. With two 3'. eeniTeaie you have ‘be careful. a walking up to it. “ 3. The Generator's capacity is 24 volts = 6 amps with, a _Separe : regulator sami can be adjusted manually. .- ms Ae Wind ioanas average between a minimum of 12 kts | toa Sir sar sete of “60 kts. : The area around where the generator is located is’ relatively “flat, ° and: the : wind sometimes gets over 75 kts but not too often.: ‘The generator requires a minimum of 6 kts to a maximum of 16 kts.to-operaté.efficientiy:=: Anything over 16 kts has no effect on increasing the voltage as it is regulated as such. .: j 5. Our system has been operating since 1974, and have ‘not,incurred any storm damage or vandalism, due to its remgte location, I imagine : 6. Operational problems. So far we have experienced very ,few. real problems “aed with our generator. The Dynamic breaking failed after some’ maintenance. personel _ tried to stop a rotation of the blades during high winds’ and corresponding ° R.P:M., so I can't really blame the equipment for that. . However,. a more: efficient way of stopping the blade rotation should be devised. We experienced, blade: pitch . failure once due to not greasing the mechanism that ‘operates ;the pitch, ©Since .: : then and ‘after contacting the eee we installed a sealed :bearing. in? ‘that area. The ‘daly other problem we have had a ‘the eee oe “he! ‘storage batteries-. , Originally we used regular automotive batteries, and the generator was set too high and boiled the water out. Thereafter we replaced them with Caterpillar, @ big truck battery, and have had no further problems.. Our T.V.. repeater will ~ continue to operate for at least two weeks without the generator operating. The T.V. repeater: ‘pulls about 4 amps when transmitting, and. ‘about l-amp: ‘when idle. wy FIG, B.2 CONT. Bob Costello February 3, 1978 ‘ Ho ld a . Page two -. a ; re Ee E A alah 2 =, off the ground for obvious reasons. ‘Also the snow ‘drifte-pretty: high | out . there on some occasions. However, the area is very remote ‘and ‘accessible ‘only. = helicopter. and not qeeianien to er maintenance. - I hope I have answered your ‘questions. : feel free to ask. : © toub truly, 1a a alle ie fs ; + G ‘ Don Caswell | Public Works Director DC/1h ee eel ete er FIG. B.2 CONT. CITY OF DILLINGHAM P.O. BOX 191 DILLINGHAM, ALASKA 99576 TELEPHONE (907) 842-5211 or 842-5212 November 26, 1979 Mr. Mark Newell Project Manager, Gambell Project Public Health Service P.O. Box 7-741 Anchorage, Alaska 99510 Dear Sir: Perhaps with some of my wind and your knowledge we can set up a feasible sounding wind-energy project for Dillingham. I am going to attempt a grant through the U.S. Department of Energy Small Grants Programs next funding cycle and I need technical assistance. As you may be aware, the city does have a wind powered generator at Juant Mountain near Portage Creek. This has been in service several years and has minimal maintenance required. Our televison translator is powered by this source. Let me know what you think of windmill supplying power for a heat on new water line to storage tank. Ee Laura M. Schroeder City Manager LMS/jen | Fig. B.2 CONT. CITY OF DILLINGHAM P.O. BOX 191 DILLINGHAM, ALASKA 99576 TELEPHONE (907) 842-5211 or 842-5212 December 5, 1979 Mr. Mark A. Newell Assistant Sanitary Engineer Dept. of Health, Education & Welfare AANHS P.0. Box 7-741 Anchorage, Alaska 99510 Dear Mark: The city just hosted an Energy Workshop sponsored by Bristol Bay Native Association. Alaska Dept. of Energy, Naknek Electric and Nushagak Elec- tric, as well as a representative from Grumman Wind Mills of New York were present. It was stated that wind data from this area and any documentation on windmills was about non-existent. Our Juant windmill] has been in operation since about '72 or '73. It costs the city under $1,000 yearly for maintenance. The State of Alaska provides repairman and I do not know actual costs accrued by them. I believe under $2,000. We have probably two periods a year when we must charge batteries by gas generator due to windmill problems. Then a resident of Portage Creek must travel to site by snow machine to fuel it. Currently its been down about 1 month. Parts are in Italy. ‘This has happened past 2 or 3 years, always under $600 in parts. ~ : I am enclosing the particulars on windmill. As far as I am concerned its relatively maintenance free in comparison to $150/month lights for each of two other translator sites. The last set of batteries I talked State Alcoholism into funding some 2 years ago. They are large heavy duty ones. Carl Larson of local State Div. of Transportation is our local maintenance man. However, Harlan Adkison of State Div. of Transportation Communication Branch “in Anchorage knows more about windmili than most. ~ - Sincerely, AtttAa— Laura M. Schroeder * 5 City Manager FIG. B.2 CONT. PENNWALT Ya AUTOMATIC POWER Manufacturers and Designers of SIGNAL AND POWER SYSTEMS NAVIGATIONAL AIDS AEROWATT MODEL 300 FP7 ~WIND-GENERATOR © P. O. BOX 18738, HOUSTON, TEXAS 77023 + (713) 228-5208 6 x THRUST 200 Kg. (440183) ei FOR WIND OF 120 MH 63200mm (i2e") ($987 19S) *xosddo By ggz :LHOISM 120") 1/2") \ ‘\ye- MAX. DEFLECTION \ 205mm ’ (8.2") 32 8HOLES 6 13mm ON 6 250mm B.C. 3260mm (130.4") | WIND GENERATOR TYPE 300 FP7 “LNOO 2’a' ‘Did T-AW 2704 73 ——__ FIG, B.2 CONT. I¥/ TECHNICAL DATA IV.1 - AERODYNAMICAL DATA - ffominal wind speed (wind speed over which the rated data are obtained) : 7 m/s (13.6 kts - 15.7 mph).* r average starting wind speed : 1.5 m/s - rated regulation wind speed : 7 m/s - rated propeller rotation speed : 420 rpm - propeller maximum rotation speed (wind speed over 7 m/s, machine off load) : 450 rpm - maximum wind speed : 60 m/s - speed regulation operation : wind speed over 7 m/s - maximum aerodynamical thrust : 200 daN IV.2 - ELECTRICAL DATA -_rated voltage : (24 V) A: 18.2 ¥ (iz~v) Ao: 9.1V - rated intensity:(24 V) 7 12,5 A (12 V) : 25 A - rated frequency : 7 Hz - winding resistance : 0.61 2 IV.3 - DIMENSIONS - propeller diameter : 3.200 mm 5 - chord of an arc : 125 mm it 1 - weight of a blade : 2.4 kg - 0.0. length : 4.315 mm + 10 - weight : 165 kg or 364 lbs - attachment : flange 280 mm dia with 8 holes 13 mm dia on a circle of 250 mm. eeleee —_———_———qjjKe—j— 2 The wind generator begins rotating when the average wind speed exceeds 1.5 m/s. But it delivers power only when the voltage is such that the rectified voltage of the battery bank, i.e. when the rotation speed is about 300 rpm, which corresponds to a 3 m/s or 4.8 kts or 6.7 mph wind speed approx. WIND ROSE — DILLINGHAM AIRPORT SOURCE: DIVISION OF AVIATION, STATE OF ALASKA, IONAL WEATHER GERVICE DATA FIGURE B.3 VARIOUS EXISTING SYSTEMS IN THE BRISTOL BAY REGION _ wat dd ieee LAKE CLARK, 1.8 JACOBS BATTERY CHARGER DILLINGHAM, 200WATT WINCO BATTERY CHARGER FISH & GAME BATTERY CHARGER ROUND ISLAND, BRISTOL BAY 10 FIG, B.3 CONT. LAKE ILLIAMNA, 1.8 KW JACOBS /DAKOTA BATTERY CHARGER LAKE ILLIAMNA, 1.8 KW JACOBS BATTERY CHARGER cs FIG, B.3 CONT. NEWHALLEN, 120 VOLT 320 AMP-HOUR BATTERY SYSTEM 12 BIBLIOGRAPHY Brower, William A. Jr., et al. Climatic Atlas of the Outer Continental Shelf Waters and Coastal Regions of Alaska, Yol. Il. Bering Sea. Alaska: Arctic Environmental Information and Data Center, 1977. Cromack, D.E. 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