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HomeMy WebLinkAboutAlaska Geothermal Development A-Plan AmandaKolker University of Alaska Fairbanks 10-2007ALASKA ENERGY AUTHORITY Alaska Geothermal Development : A plan October 2007 Author: Amanda Kolker Alaska Energy Authority Geothermal Development Intern & PhD Candidate: University of Alaska Fairbanks, Department of Geology and Geophysics Table of contents Page No.  Problem statement 3  Introduction: geothermal energy 3 Geothermal energy from hydrothermal systems 3 Geothermal energy from non-hydrothermal systems 4 Sustainable geothermal energy production 4  Geothermal energy in Alaska 4  Geothermal development costs in Alaska 6  Criteria used to prioritize Alaskan geothermal projects 6  Priority projects for AK geothermal development 1. Exploration / resource confirmation at Mt. Spurr 7 2. Drilling on Unalaska Island 8 3. Exploration/confirmation at Akutan Volcano 9 4. Feasibility study for Manley Hot Springs 10 5. Deep drilling at Chena hot springs 11 6. Exploration in the Southern Seward Peninsula region 12 7. Exploration on Northern Alaska Peninsula 13 8. Feasibility of economic development at Pilgrim Hot Springs** 13 9. Exploration at Goddard Hot Springs and Mt. Edgecombe 14 10. Exploration at Bell Island Hot Springs 15 11. Drilling for district heating purposes at Kotzebue 16 12. Exploration at potential village relocation sites 17 13. Exploration in the Susitna basin 17 14. Exploration at Eastern Copper River Basin 18  General Priorities 19  References 21 * The order in which these projects appear is subject to change. ** The Pilgrim Hot Springs project could become a higher priority if the 60 -mile transmission line to Nome became less prohibitively costly (see p. 21) Problem statement The Problem: Development of the most economic geothermal resources in Alaska for the benefit of its residents. The cost of electric power in rural Alaska is among the highest in the United States. ecent technological advances have previously not considered economic for power generation. For example, Chena Hot Springs installed the first geothermal power plant in Alaska in 2006. It uses Chena Hot Springs is one of over 30 hot springs in the Central Alaska Hot Springs Belt (CAHSB). Concerns about climate change and the likelihood of carbon taxes on fossil fuel use make geothermal energy an even more attractive option. Unfortunately, prospective geothermal projects also face significant challenges: the distance between resources and users, the high cost of exploration, and the high capital cost of development, to name a few. The uncertainty regarding future fossil fuel prices and carbon taxes adds to the challenge. To assist in focusing on the geothermal prospects with potential to deliver the most benefits to Alaskans, the Alaska Energy Authority (AEA) offers below a list of 14 projects. This list was assembled from available data and could change based on future exploration. Introduction: geothermal energy Geothermal Energy from Hydrothermal Systems eothermal heat is usually exploited for energy via hydrothermal systems Hydrothermal systems contain hot fluid or vapor or both, depending on pressure and temperature conditions. have three components: 1) a heat source 2) circulating groundwater, and 3) a „plumbing system‟ of vertical permeability enabling convection of groundwater around the heat source. The heat source can be shallow (magma) or deep (3-4 km or greater). Geothermal power plants use one of three technologies to generate electricity from hydrothermal fluids: (1) dry steam, (2) flash, and (3) binary cycle systems. In dry steam plants, hydrothermal vapor is tapped and routed directly through turbine/generator units to produce electricity. Flash steam plants use hydrothermal fluid at temperatures greater than 182 °C that is delivered under high pressure to the surface. The fluid is then depressurized, causing some of it to flash to steam, which then drives turbines/generators. Most geothermal areas, however, contain water below 182 °C. These fluids must be run through the binary-cycle, where hydrothermal fluid and a secondary (“binary”) fluid pass through a heat exchanger, causing the binary fluid to vaporize, which then drives a turbine. The temperature requirements for binary systems depend on site characteristics (available condensing temperature, volume of geothermal fluid, etc.). The binary system at Chena Hot Springs uses geothermal fluid at ~80°C. Geothermal Energy from Non-Hydrothermal Sources This requires 1) engineering a fractured reservoir into a high-heat flow region by down-hole explosive devices; 2) injecting water into the engineered reservoir; 3) pumping hot water and/or steam to a power plant and reinjecting spent fluids. There are few EGS systems in production in the world: some examples are Cooper basin (Australia) and Soultze basin (France). Geopressurized systems do not use steam. Instead, hot brine (minimum 350 °F) trapped in deep subsurface formations is pumped to the surface and used to power hydraulic turbines. Since the brine is not circulating in the subsurface, these systems are more akin to oil deposits than circulating hydrothermal fluids – that is, the brine is a finite resource (non-renewable because there is no recharge of groundwater). Using geopressured fluids for geothermal power is perhaps most appropriate in the case of abandoned oil wells, where deep holes have already been drilled. Sustainable Geothermal Energy Production In geothermal power plants, spent fluid is typically reinjected into the system to “recharge” the system with water, thereby keeping the resource “renewable.” . Geothermal energy in Alaska Background and Previous Work Alaska‟s geologic setting is highly favorable for the existence of exploitable hydrothermal energy. There are over 100 known hot springs in the state (NGC, 1980). Most exploratory geothermal work in Alaska occurred during the period 1970-1985. During this period, Alaska‟s Division of Geological and Geophysical Surveys (ADGGS) of the Department of Natural Resources catalogued and sampled all known surface expressions of geothermal systems in the state. Preliminary exploration work was conducted in Southeast Alaska, the Seward Peninsula, and the Aleutian arc. Preliminary exploration studies were started for Interior Alaska but never completed. Geothermal Resources of Alaska: An Overview The Aleutian Volcanic Arc, which includes the Aleutian Islands as well as volcanoes on Alaska Peninsula and W. Cook Inlet, is Alaska‟s most promising setting for geothermal energy. However, most geothermal sites in the Aleutians are too remote from population centers to be economically viable. 56 geothermal systems have been identified in the Aleutian arc; many more likely exist but remain unknown due to poor surface expression (Motyka et al, 1993). The bulk of geothermal exploration in the Aleutian Arc occurred at 3 sites: Mt. Adagdak, Mt. Makushin (Unalaska Island), and Akutan Island. Mt. Makushin is the only site that has been drilled. Temperatures close to 200 °C were discovered at ~400 m depth. Central Alaska Hot Springs Belt (CAHSB). Though the CAHSB spans numerous geologic provinces, thermal springs in the CAHSB are remarkably similar. They all have temperatures between 30 and 88 °C (average ~55 °C) of alkali-chloride type waters (Miller et al, 1973). Most of the sites lie within discontinuous permafrost, occurring as elongate zones of springs and seeps. The local geology of most CAHSB sites is poorly defined. Due to lack of data, the heat source driving the geothermal activity has not been established. They are probably fault-related and may also be related to radioactive heating by nearby plutons. While none of the Interior CAHSB hot springs show any relation to recent volcanism, the extreme western part of Alaska may be an active rift zone with abnormally high crustal heat flow and the possible presence of shallow magma. The Wrangell Volcanic Cluster is another potential geothermal resource in Alaska. There are few thermal springs associated with the Wrangell volcanic complex, and only Mt. Wrangell itself has an active thermal area. The Eastern Copper River Basin (ECRB), close to the western part of the Wrangell volcanoes, has been the subject of geothermal exploration because it contains mud volcanoes, unusual features associated with pressurized groundwater and/or hydrothermal aquifers (Wescott and Turner, 1983). Alaska Panhandle. Minor, isolated episodes of recent volcanism occur near Mt. Edgecumbe and at small vents on Revillagigedo Island. These areas have not been explored for geothermal potential due to the lack of surface manifestations. Resource Capacity of Alaskan Geothermal Systems The capacity of a geothermal resource, whether in terms of electrical or heat energy, depends on regional heat flow, vertical permeability (faulting/fracturing of geothermal host rock), and the recharge rate of both heat and water. None of these parameters are known for the bulk of Alaska‟s geothermal sites. Based on analogous systems in the Pacific Ring of Fire, Geothermal development costs in Alaska Prospecting and field analysis includes: Geochemical surveys (gas, water, soil and rock) and isotope studies Chemical geothermometry using water composition data Temperature-gradient drilling (shallow, slimhole wells) and heat flow surveys Geologic logging of shallow boreholes Geologic cross section or subsurface modeling using supplementary geologic and geophysical data (gravity, seismic, etc.; note that this data is often lacking in AK) Hydrologic studies Geophysical surveys to locate fluid and fluid pathways Remote sensing surveys Criteria used to prioritize Alaskan geothermal projects All costs reported in 2007 dollars. Resource Evaluation Land costs (exploration leases) $3 / acre + bid Roads and access $500,000-$1,000,000 / mile Prospecting & field analysis $100-$200 / kW (Hanse 2005) Shallow gradient hole drilling $0.8-2 M / well (GeothermEx, 2004) Exploration drilling (success rate 20-25%) $0.8-2 M / well (GeothermEx, 2004) Well testing $70,000-100,000 / well (GeothermEx, 2004) Resource confirmation and development Confirmation drilling (success rate 80%) $0.8-2 M / well (GeothermEx, 2004) Administration 7.5 % total confirmation costs (GeothermEx, 2004) Production and Transmission Drilling production & injection wells $2 M / well (GeothermEx, 2004) Physical plant $350-$500 / sq. ft (Dilley, 2007) Turbines / generators $1300 -$6000 / kW (Holdmann, 2006; USGS, 2007) Shipping $50 / kW (Holdmann, 2006) Gathering system (pipes, pumps) $250 / kW (Hanse 2005) Transmission line $500-$750,000 / mi (Dilley, 2007) Access Roads $500,000-$1,000,000 / mile Priority # 1: Geothermal exploration and resource confirmation at Mt. Spurr Beneficiaries: ElimElim SitkaSitkaNaknekNaknek ManleyManley ChenaChena Bell IslandBell Island Susitna BasinSusitna Basin PilgrimPilgrim MakushinMakushin AkutanAkutan KotzebueKotzebue Mt. Mt. SpurrSpurrNelson IslandNelson Island Copper RiverCopper River ElimElim SitkaSitkaNaknekNaknek ManleyManley ChenaChena Bell IslandBell Island Susitna BasinSusitna Basin PilgrimPilgrim MakushinMakushin AkutanAkutan KotzebueKotzebue Mt. Mt. SpurrSpurrNelson IslandNelson Island Copper RiverCopper River Background and Previous Work . Hence, the geothermal leases to be issued in February 2008 must be written to facilitate these goals. Specifically, the lease terms should (1) provide incentives for exploration; (2) require that exploration results are made available to the public during or after the lease term; (3) require development of the resource if it is found. The risk is that a leaseholder may “sit on” the lease for years, with no benefit to the state (see p. 19). Priority # 2: Geothermal drilling on Unalaska Island Background and previous work Future work priorities Priority # 3: Geothermal exploration/confirmation at Akutan Volcano Beneficiaries: City of Akutan, Trident Seafood Background and previous work The City of Akutan currently has two power generation facilities; a diesel facility (150 kW) and a facility that contains a 105 kW hydro plant with a 125 kW diesel generator. Both power plant facilities feed Akutan‟s power distribution grid. The average power generation year-round in 2006 was 46 kW. Trident Seafoods, a large processor on the island, currently generates its own power via diesel but the company has expressed interest in purchasing power in the future from Akutan Electric Company. Akutan volcano is an active volcano with 32 historic eruptions. Several thermal springs and a small fumarole field are located in Hot Springs Bay valley, which lies 4 km northwest of Akutan Harbor, ~8 km from Akutan village. The fumarole field lies between the volcano‟s summit and Hot Springs Bay valley. Temperatures of the hot springs range from 40-84°C, and fumarole temperatures as high as 99 °C have been measured Geothermal exploration was conducted at Akutan in the mid-1980‟s (Motyka and Nye, 1988). These studies suggested that a deep reservoir could extend more than 4 km beneath the geothermal area (Motyka & Nye, 1988). It is likely that the fumaroles are fed directly by gases and steam boiling off the deep hot reservoir and that these fluids then mix with cool meteoric waters to produce the hot springs waters further down the valley. Chemical geothermometry gives estimated reservoir temperatures between 180º to 200 ºC Future work priorities The next logical step is confirmation of the resource at Akutan by shallow exploration drilling and deep geophysical surveys. These studies are necessary to both define the capacity of the geothermal resource at Akutan and to help locate production wells. It is also necessary to gather together the stakeholders (Trident Seafoods, Aleut Regional Native Corporation / Aleutians East Borough, Akutan Village Corporation, Native Village of Akutan, City of Akutan, and private leaseholders) to plan project development. Depending on the temperature and pressure of the geothermal fluid encountered, hydrothermal fluids on Akutan Island could be developed for power generation using either a binary ORC (Organic Rankine Cycle) turbine similar to the one at Chena Hot Springs or a flash cycle power plant (if temperatures exceed 180 °C). A 10 MW plant size was proposed in 1994 based on existing information about the resource potential and projected energy demand for Akutan. This output could be escalated incrementally to 40 MW or more depending on demand. Priority # 4: Feasibility study for Manley Hot Springs Background and Previous Work AEA applied for technical assistance from the US Department of Energy's GeoPowering the West (GPW) Initiative and the National Renewable Energy Laboratory (NREL) to conduct a feasibility study of geothermal project opportunities for Manley. Millennium Energy LLC, a renewable energy consulting firm, was tasked to investigate the potential of geothermal development at Manley Hot Springs, including the following applications: district heating, greenhouse heating, lodge or resort development, swimming pool development, community cold storage, and/or power production. The first step in this investigation was to conduct a scoping study to determine whether all of the aforementioned applications should be looked at in a cursory, qualitative manner -- or if conducting a detailed technical and economic feasibility study on the most likely application would be the best course of action. This study was completed in spring 2007. Future work priorities Priority #5: Deep drilling at Chena Hot Springs Beneficiaries: All CAHSB prospects; Chena Hot Springs resort Background and Previous Work The Chena Hot Springs (CHS) geothermal power plant project has been hailed as a success in terms of local, renewable energy usage. As a result, many geothermal projects are springing up to follow suit all across the Central Alaska Hot Springs Belt (CAHSB), and t . CHS is located in the eastern part of the CAHSB. An extensive study of the shallow hydrologic system at CHS was carried out 2005-2006 out as part of a D.O.E.- funded Geothermal Resource Evaluation and Definitions program (GRED III). Geologic mapping, geochemistry, airborne and ground-based geophysics, hydrology, reservoir engineering, remote sensing, and thermal gradient studies were all conducted as part of the GRED III study. A total of 16 shallow (< 400 m) wells have been drilled in the area, 11 as part of the GRED III project. This study was conducted concurrently with installation of the power plant at CHS. Results of those studies have recently been published (see Erkan et al, 2007 and Kolker et al, 2007). Future work priorities Future work is necessary to determine a general resource capacity for CAHSB geothermal systems based on a generalized resource model and incorporating recent technological advances in utilizing low-temperature resources.The model would have to include, among other things: 1) a heat transfer mechanism; 2) fluid pathways; 3) recharge rates of heat and water. The hot springs in the CASHB most likely reflect a mixture of thermal fluids and cold groundwater (Miller et al, 1973; Kolker et al, 2007). At CHS, only shallow wells have been drilled (max. ~300 m) and thus the deep reservoir fluid – that is, geothermal fluid uncontaminated by groundwater infiltration – has still not been encountered. A deep well (1000 m or deeper) was planned for summer 2007, but this was cancelled due to budget cuts in the USDOE‟s geothermal program. Since Chena Hot Springs represents one of 30+ hot springs that have potential to power communities in Alaska, a deep well is of utmost importance in terms of characterizing the geothermal resource. Priority # 6: Geothermal exploration in Southern Seward Peninsula area Background and Previous Work There are 4 hot springs clustered in the Southern part of the Seward peninsula, relatively close to several communities. These hot springs are: Elim (“Kwiniuk”), 105 °F; Clear Creek, 145 °F; White Mtn., 120 °F; and Battleship Mtn. 66°F. None of the springs have been explored for geothermal potential beyond basic temperature and chemistry surveys. Elim Hot Springs was visited in a reconnaissance trip by Gerry Huttrer of Geothermal Management Company, Inc. in 2002, who gave the following report: Future work priorities Because Mr. Huttrer did not assess any of the other hot springs in the area with hotter water, and because his visit preceeded the geothermal development at Chena Hot Springs, his assessment deserves a fresh look. The four hot springs should be individually assessed and one of the four chosen as a potential power site. a general resource capacity for CAHSB geothermal systems will help indicate whether geothermal power and heat production on the Southern Seward peninsula is economically feasible, and where. If it is, a technical feasibility study should be done, similar to the one cond ucted for Pilgrim hot springs and proposed for Manley. Priority # 7: Geothermal exploration on Northern Alaska Peninsula Background and Previous Work 450 miles of transmission between 24 villages in southwest Alaska, including 24 miles of transmission under Lake Iliamna. The cost has been estimated at $200M. Future work priorities Priority #8: Feasibility of economic development at Pilgrim Hot Springs Background and Previous Work Pilgrim Hot Springs is a Known Geothermal Resource Area Through the USDOE GeoPowering the West (GPW) Initiative, AEA conducted a feasibility study of geothermal project opportunities for Pilgrim Hot Springs. The consulting firm HDL Inc. was tasked to prepare a preliminary feasibility study of geothermal power production from Pilgrim Hot Springs and transmission to Nome. The study evaluated the previous scientific studies conducted in the area to assess the feasibility of this proposed development. It was completed in spring 2007. The study showed that the transmission ~60 miles to the cit y of Nome would cost up to $45 million, dwarfing even the high drilling costs and making the project economically unfeasible. Future work priorities Unless something changes with respect to the cost of transmitting geothermal power to users (see p. 20), power transmission to Nome appears to be prohibitively costly (Dilley et al, 2006). However, further and more detailed analysis of the idea of exporting geothermal power from Pilgrim over an intertie should be conducted. The State should also consider conducting a feasibility study of creating economic opportunity for Mary's Igloo tribe and other regional residents in the form of agriculture and other development based on geothermal heat and power. This could be a stepping stone to power generation for a mine or for Nome. Priority # 9: Geothermal exploration at Goddard Hot Springs and Mt. Edgecumbe Anticipated future changes to the community: “The city needs to increase its electrical generation capacity and the… proposals currently being explored are presenting huge licensing and financial challenges.” –Kerry Maclane, community development consultant Background and Previous Work Mt. Edgecumbe volcano is one of the few active volcanoes in Southeast Alaska but has not been active in historic time (Wood and Kienle, 1990). The volcano is located miles west of Sitka, across hot springs or fumaroles on or near the volcano. Because of this lack of surface expression, there has been no geothermal exploration at Mt. Edgecumbe volcano. Goddard Hot Springs is one such system, located approximately 15 miles south of Sitka. The hot springs are owned by the city of Sitka. Goddard is one of the hottest springs in Southeast Alaska, but the shallow hydrothermal system is thought to be of limited extent. Limited geothermal exploration was conducted at Goddard in the early 1980‟s (Economides et al, 1982). Future work priorities The City of Sitka has expressed interest in exploring the resource potential of nearby geothermal sites, and there is strong support from members of the Assembly for such a project. The community is interested in power as well as cascaded uses of geothermal such as chilling (for seafood processing) and heating (buildings and greenhouses). Goddard Hot Springs appears to be suitable for binary power production similar to Chena Hot Springs – but Mt. Edgecumbe could be better. Initial exploration efforts should focus on producing data that would facilitate choosing between the two sites. More standard exploration work would follow. Priority # 10: Exploration at Bell Island Hot Springs Distance between resource and load: The Swann-Tyee Intertie crosses ~3 miles from the hot springs; however, it might be possible to produce power from closer to the intertie. Background and Previous Work Future work priorities Bell Island is of interest because it is within 3 miles of the right of way for a proposed intertie between Swann Lake and Tyee Lake hydroelectric projects. Very little geothermal exploration work has been conducted at the site. Geothermal exploration should begin by constraining the lateral extent of the geothermal reservoir and whether it would be possible to produce power for the intertie with a minimum of transmission. Priority # 11: Drilling for district heating purposes at Kotzebue Background and Previous Work The city of Kotzebue and Kotzebue Electric Association staff has been actively collaborating with local, state, and federal agencies to encourage project development. They have collected available geologic information (seismic, gravity, and other information) and submitted two separate grants to USDOE for funding. A geothermal district heating system in Kotzebue was studied in the 1980‟s. That study explained that the proposed Kotzebue geothermal project “does not involve geothermal systems and geothermal wells as they are normally considered in geothermal exploration. That is… fault and fracture systems, influx of meteoric waters into the system, and resultant hot waters … are not involved. Rather, this geothermal system must rely on large volumes of warm water that can be produced from a sedimentary basin where the original formation waters are trapped.” (ESI, 1981b). There is an oral tradition that claims that hot fluid was once encountered at 300 ft depth beneath the city of Kotzebue. The water was reportedly found during foundation work for a hospital (?) in the 1950‟s. In direct contradiction to this rumor, AEA reports mention that the Kotzebue region sits atop approximately 1000 feet of permafrost. This author was unable to find any driller‟s logs from the Kotzebue area to sort out the mutually contradictory claims, and the source of the rumor remains mysterious. Future work priorities The next step in the proposed Kotzebue geothermal district heating project should be to verify the rumored hot water beneath the city of Kotzebue by shallow drilling. If that is verified, future work should focus on the following questions: (1) How thick is the permafrost beneath Kotzebue? What is the relationship between permafrost and thermal waters? How would circulation of heat below Kotzebue affect the permafrost? (2) If warm water is extracted from subsurface formations, subsidence at the surface could be a real danger as Kotzebue is less than 10 feet above sea level. How would the engineering of the system prevent this from happening? The city of Kotzebue plans to complete the exploratory phase in summer 2008. This includes drilling a 2,300 ft bore hole using a BLM drill rig (the availability is not yet confirmed). In winter 2008, the project design phase will be implemented. The type of project (UTC turbine for electricity generation or a district heating system) and its design will depend on the volume and temperature of available fluids. Construction is slated to begin summer 2009. Priority # 12: Geothermal exploration at proposed relocation sites Newtok, Shishmaref Newtok: Shishmaref: Newtok: Shishmaref: Newtok: resource unknown; Shishmaref: resource in Bering Strait National Preserve Newtok: $0.Shishmaref: $0.47 Background and Previous Work Future work priorities The Newtok (Nelson Island) and Shishmaref (Serpentine Hot Springs) prospects are in the initial stages of discussion. For Newtok, subsurface data from Nelson Island will have to be obtained before an exploration plan can be initiated. This data will be available through the US Army Corps of Engineers by early 2008. For Shishmaref, the first step as of 2007 would be to discuss the scenario with the community and get their feedback. The second step would be to work with the National Park Service to consider either a land swap or some other arrangement. Priority # 13: Geothermal exploration in the Susitna Basin Willow and Wasilla (heating); Railbelt grid (power) Willow: 1,973 Wasilla: 6,775; Resource potential unknown Willow-possibly within a few miles of resource. unknown Railbelt grid= $0 – 0.25/kWh depending on energy source (hydro, gas, diesel, naptha, coal) None Background and Previous Work ° ° Future work priorities Priority # 14: Geothermal exploration at Eastern Copper River Basin Glennallen and (CVEA) network Glennallen: CVEA network Resource potential unknown Glennallen ~20 miles from Upper Klawasi spring Unknown Unknown Background and Previous Work . Future work priorities When the 14 geothermal prospects outlined in this report are considered as a whole, a number of common themes emerge. First, there is a noticeable lack of exploration data for most of Alaska‟s geothermal resources – and often what little data exists is not publicly available. The exploration data that exists is almost exclusively from the 1970‟s and early 1980‟s. Second, many advances in geothermal assessment and technology over the last few decades have escaped the notice of Alaska‟s energy community. For example, Alaska lacks a high-resolution heat flow map such as those that have been generated for most states in the U.S. from borehole data, despite the fact that abundant data of this type exists for Alaska. Third, there is no systematic way to choose between different power generation options for a given location. The state government needs some systematic method of assessing power alternatives that encompasses market externalities, long-term costs and benefits, and other factors vital to making long-term decisions about energy supply. most Alaskan geothermal projects “stall out” at the drilling phase. 1. Update geothermal leasing process to facilitate exploration and development. term expires. This means that Mt. Spurr could be locked up in a private lease for another 10 years with no benefit to the state. Secondly, i 2. Develop an online interactive public database of geothermal data as part of the Alaska Energy Inventory project. Since most of the publicly available data on Alaska‟s geothermal potential was collected before 1985, very little of that data is electronic and it is therefore difficult to access for most interested parties. The Division of Geological and Geophysical Surveys has digitized most of their publications, but many datasets within the AEA library, the University of Alaska Fairbanks Rasmussen Library, the UAF Geophysical Institute Library, and elsewhere have not been digitized. These publications should be inventoried and digitized as part of the State‟s Alaska Energy Inventory project. 3. Develop a high-resolution heat flow map for Alaska from oil & gas well data. 4. Create a model for long-term Cost-Benefit Analyses (CBAs) of “base case” (diesel) vs. geothermal energy case. Like other renewables, The CBA model should include capital costs, O&M costs, life-cycle costs of the system, fuel costs, and any anticipated costs (carbon taxing, etc.) within a project lifetime of ~30 years. It should also include externalities that may affect costs. Many of t job opportunities, etc.) (embedded costs of fuel, pollution costs, etc) 5. Develop cost-share program for geothermal drilling. any federal and state cost-sharing programs have been implemented for geothermal drilling; in fact, eight out of the twelve geothermal developments of the past decade in the Western US were financed via cost-shares, some as high as 80% federally- and/or state-funded (Marshall Reed, personal comm.). 6. Consider power transmission lines from geothermal sites to users as capital improvement projects. Renewable energy sources are highly site-specific. Often, power generated by a renewable supply must be transmitted a significant distance to users. This is especially true in Alaska where population centers are scarce and geothermal sites tend not to be laterally extensive. Unfortunately, transmission lines in Alaska are expensive (see p. 6). Hence, transmission is usually the most prohibitive cost component of a geothermal development proposal in Alaska (dwarfing even the high costs of drilling). Thus, the state should consider transmission lines for renewable energy projects as large-scale capital improvement projects Such projects tend to have certain near-term monetary costs but highly uncertain and hard-to-quantify future benefits. 7. Monitor existing geothermal projects for sustainability. References Barbier, E., 2002. Geothermal energy technology and current status: an overview. Renewable and Sustainable Energy Reviews, 6(1-2): 3-65. Economides, M., 1982. Drilling and Reservoir Engineering Analysis of Pilgrim Hot Springs, Alaska, University of Alaska Fairbanks, Fairbanks, Alaska. Energy Systems, Inc., 1981a. Kotzebue Geothermal Project Final Report: Summary of Project Tasks and Findings. Report to the State of Alaska Div. of Energy and Power Development, 5p. Energy Systems, Inc., 1981b. Kotzebue Geothermal Project: Geologic Analysis. Report to the State of Alaska Div. of Energy and Power Development, 32p. Erkan, K., Holdmann, G., Blackwell., D. and Benoit, W., 2007. Thermal Characteristics of the Chena Hot Springs Alaska Geothermal System, Stanford 32nd Workshop on Geothermal Reservoir Engineering, Stanford University, California, pp. 117-124. GeothermEx, Inc., 2007.http://www.geothermex.com/frame_e.html Holdmann, G., Blackwell., D. and Benoit, W., 2006. Chena Hot Springs GRED III Project: Phase 1 Report, Unpublished report to USDOE. Chena Hot Springs Resort, Fairbanks, AK. Kolker, A., Newberry, R., Larsen, J., Layer, P. and Stepp, P., 2007. Geologic Setting of the Chena Hot Springs Geothermal System, Alaska., Stanford 32nd Workshop on Geothermal Reservoir Engineering, Stanford University, Palo Alto, CA. Miller, T.P., Barnes, I. and Patton, W.W., 1973. Geologic Setting and Chemical Characteristics of Hot Springs in Central and Western Alaska. USGS Open-file Report No. 575. Motyka, R.J., Hawkins, D. B., Poreda, R. J., Jeffries, A., 1986. Geochemistry, isotopic composition, and origin of fluids emanating from mud volcanoes in the Copper River Basin, Alaska. Public Data File 86-34, Alaska Division of Geological & Geophysical Surveys. Motyka, R.J., Liss, S.A., Nye, C.J., Moorman, M.A., 1993. Geothermal Resources of the Aleutian Arc. Alaska Division of Geological & Geophysical Surveys, Professional Paper 114. Motyka, R.J., Forbes, R.B. and Moorman, M., 1980. Geochemistry of Pilgrim Springs Thermal Waters, Geophysical Institute, University of Alaska Fairbanks, UAG R-271, Fairbanks, Alaska. Motyka, R., and Nye, C. 1988. A geological, geochemical, and geophysical survey of the geothermal resources at Hot Springs Bay Valley, Akutan Island, Alaska. ADGGS report of investigations 88- 3, 115 p. Motyka, R.J., and Moorman, M.A., 1987, Geothermal resources of southeast Alaska: Alas ka Division of Geological & Geophysical Surveys Professional Report 93, 1 sheet, scale 1:1,000,000. NGC, 1980. Thermal springs list for the United States. National Geophysical Center. Nichols, D.R. and Yeihle, L.A., 1961. Mud volcanoes in the Copper River Basin, Alaska. In: G.O. Raash (Editor), Geology of the Arctic. Proceedings, International Symposium on Arctic Geology, Calgary, Canada, pp. 1063-1087. NOAA, 1983. Geothermal resources of Alaska. National Oceanic and Atmospheric Administration, pp. 1:2,500,000 scale map by NOAA National Geophysical Data Center, data compiled by Alaska Division of Geological & Geophysysical Surveys. PolarConsult, Alaska, 1989. Kotzebue District Heat Study. Report to AEA, 30p. SMU, 2004. Heat flow map of Alaska. Southern Methodist University Geothermal Laboratory. Stefansson, V., 2000. The Renewability of Geothermal Energy, Proceedings World Geothermal Congress, Kyushu, Japan. Turner, D., L. & Swanson, S. E., 1981. Continental Rifting - A New Tectonic Model for the Central Seward Peninsula.. Wescott, E.M., Turner, D.L., Nye, C.J., Beget, J.E., and Motyka, R.J., 1985, Preliminary report on geothermal resource investigations at Mt. Spurr, Alaska: Alaska Division of Geological & Geophysical Surveys Public Data File 85-65, 22 p. Wisian, K.W., Blackwell, D.D. and Richards, M., 2001. Correlation of heat loss and total energy production for geothermal systems. Geothermal Resources Council Transactions, 25: 332 -335.