Geothermal Energy Options. Elim, Alaska. Gwen Holdmann / Chris Pike / George Roe

Transcription

1 Geothermal Energy Options Elim, Alaska Gwen Holdmann / Chris Pike / George Roe

2 Discussion Items ACEP Introduction Background on geothermal energy Local hot springs resource Possible applications Next steps (discussion)

3 Role of ACEP and the University of Alaska Developing information for decision makers o o Technology testing and optimization (industry) Energy analysis (policy makers, communities) Preparing students to work in energy-related disciplines Commercializing energy innovation

4 Testing and System Optimization Both in the laboratory and in the field Recent lab-based examples include: Electratherm, Sustainable Automation grid-forming inverter, Prudent Energy flow battery, Williams flywheel (next up) ACEP Energy Technology Lab (L) and Premium Power Installation in Kotzebue (R)

5 Example: Geothermal Industrial Process Energy Using Organic Rankine Cycle technology for waste heat recovery Electratherm 50kW ORC System Electratherm testing at UAF Pratt & Whitney 280 kw ORC System 5

6 ACEP Projects are Statewide Islanded electric grid integration River hydrokinetics Low temperature geothermal Remote sensing/thermal imaging Waste heat utilization Coal-to-liquids technology Biomass energy Transmission and distribution Fuel additives assessment Small modular nuclear reactors Advanced energy storage Ground source and seawater source heat pumps Stranded renewable resources assessment Waves resource assessment

7 Cosmos, August 2008

8 OurENERGY.com

9 How Geothermal Power is Generated Production/Injection Well Flow Diagram Production Well Injection Well Geothermal Education Office 2000

10 Binary Power Plant Technology Turbine Generator R134a Refrigerant Heat Exchanger Reinjected Geothermal Water Geothermal Water (from production well)

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15 Geothermal Energy The two highest temperature geothermal resources outside the Alaska Peninsula and Aleutians are located on the Seward Peninsula Serpentine Hot Springs Pilgrim Hot Springs

16 ACEP Geothermal Resource Assessments Nome/Pilgrim Chena Hot Springs Manley Hot Springs Tenakee Hot Springs Granite Mountain Shungnak Akutan Adak Atka Elim

17 Granite Mountain Resource Assessment Funded by NANA through WH Pacific

18 Shungnak Resource Assessment

19 Tenakee Springs Resource Assessment

20 Pilgrim Hot Springs Resource Assessment Clockwise from left: ACEP shallow drilling program; confirmation drilling program in 2013, community meeting in Teller; thermal mapping of region. ACEP been involved in multiple aspects of assessing geothermal energy as an option for Nome, including an extensive resource assessment, economic analysis, fuel pricing, and integration with existing generation sources. In collaboration with: AEA, US DOE, Unaatuq, BSNC, NSEDC, the City of Nome and NJUS, SNC, WMNC, TNC, MINC, USGS

21 Low-temp geothermal direct use Images from Chena Hot Springs Resort

22 Case studies

23 Tenakee Springs Community-use soaking tub Geothermal heating of changing room and nearby warehouse refurbishment by local volunteers and community donations with Rasmuson Foundation support Images & information from: Direct Use: Pool Hot Tub - Bathhouse

24 White Bear Hot Springs Geothermal water is piped to remote 1970 s era multi-room cabin and used for space heating Temperature at source:~140 F Natural flow from spring:70 gpm ¼ mile of on-ground insulated 4-inch PVC pipe Gravity feed, no pump required After the water is used for heating, it is discharged into its natural drainage area. Direct Use: Space Heating

25 Midland, South Dakota District energy system Began as source of heat for school Eventually expanded to other community buildings and swimming pool The waste geothermal water is used to water cattle, before being released into the Bad River at the edge of town. Lund, J., J. Nemec, and R. Vollmer. "Midland, South Dakota geothermal district heating." TRANSACTIONS- GEOTHERMAL RESOURCES COUNCIL (1998): Direct Use: Space Heating

26 Tolovana Hot Springs Wilderness site 45 miles northwest of Fairbanks Accessible by trail, bush plane and canoe

27 Meyer s Farm Bethel, Alaska Provides the local community with fresh organic vegetables Short term volunteers work at the farm for room and board Uses a combination of raised beds and greenhouses

28 Geothermal Heat for Aquaculture Farming tropical fish and alligators in Idaho for food and hides.

29 Geothermal Heat For Fish Drying Drying fish, seaweed, and kelp for export in Iceland Fish drying in 1977 Using geothermal heat to dry fish

30 Local hot springs resource and possible applications

31 Hot springs nearest to Elim Elim Clear Creek Temperature: Surface: F High sub-surface: F Natural flow rate: 211 gpm Distance by trail: 17 miles Elim Hot Springs Temperature: Surface: F High sub-surface: 158 F Natural flow rate: 22 gpm Distance by trail: 11 miles What is local knowledge of hot spring flows? How have they been used before?

32 Hot springs energy use at Elim Pool / Hot tub / Bathhouse Greenhouse Mushroom growing Food-drying Aquaculture Space heating Water pre-heating Heat-driven refrigeration From (accessed 24 March 2014) adaptation of Lindal, B. (1973) Industrial and Other Applications of Geothermal Energy.

33 Could the resource be developed for power generation? How hot is the resource? Kwiniuk geothermometer indicates 70 C (158F) Clear Creek 77 to 91 C (max 195F) Chena 120 to 128 C (262F) Pilgrim 135 to 145 C (293F)

34 Assume Clear Creek is tapped for power generation Back of the envelope calculations (truly) Clear Creek 77 to 91 C (max 195F) Assume generate 150kW, using 200gpm of 165ºF fluid Transmission line costs $250k/mile x 17miles = $4.25M Drilling and power plant construction ~$5M (wild guess) Energy storage? Interconnection? $1M Total cost ~$11M Elim power sales ~1.1M kwhrs/year, fuel portion of electricity cost is 35cents/kWhr Wild estimate of total cost is $11M Assume we displace all diesel generation Savings is $385,000 per year Simple payback is ~30 years

35 Should water be piped to Elim? Back of the envelope calculations (truly) Clear Creek source, (165 ºF, 200 gpm, 200 days/year) On-ground piping cost: 175,000 $/mile 17 mile pipeline Additional costs for infrastructure build out at both ends Elim uses ~105,000 gallons of diesel fuel for heating annually; assume offset about 65,000 gallons 3 M$ for pipeline only. $7M total likely 735mMbtu thermal energy Possible uses: pre-heating, district heat Value annually assuming $6 fuel = $310k Payback is ~22 years

36 Direct use of hot springs energy Pool / Hot tub / Bathhouse Greenhouse Mushroom growing Food-drying Aquaculture Space heating Water pre-heating Heat-driven refrigeration

37 Direct use of hot springs energy Clear Creek (65 C) Kwiniuk (45 C) From (accessed 24 March 2014) adaptation of Lindal, B. (1973) Industrial and Other Applications of Geothermal Energy.

38 Possible next steps Community meeting to assess interests & preferences regarding use of the hot springs Assemble locally-available information about hot springs (e.g., thermal conditions, pictures, usage history, trails) Collect additional thermal samples and map hot spots identified locally Assess interest in school-related data gathering / pilot study Develop preliminary design concepts and cost estimates for community areas of interest

39 For more information contact: Gwen Holdmann: / gwenholdmann@alaska.edu Chris Pike: (907) / cpike6@alaska.edu George Roe: / gmroe@alaska.edu acep.uaf.edu

40 Supplemental Information

41 Community information

42 Photo source:

43 Community data Population: approximately 350 Economy Subsistence: fish, seal, walrus, beluga whale, reindeer, moose Cash: commercial fishing (39 permits), government offices, school, small businesses Affiliations Federally-recognized tribe: Native Village of Elim Non-ANCSA Property ownership & mineral rights Regional non-profit corporation: Kawerak

44 Climate Subarctic climate with maritime influences Summers: Cool and moist, 46 to 62 F average Winters: Cold and dry, -8 to +8 F average Precipitation averages: Rainfall 19 in/yr, Snowfall 80 in/yr Norton Sound ice-free mid-june through mid-november Permafrost at some locations in region

45 Elim Energy Data Electricity - FY 2013 residential & community facility 60 /kwh (19 /kwh after PCE) Diesel-generated: 1,190,778 kwh 92,012 gallons of fuel at 3.90 $/gal Fuel cost: $358,794 Heating Boiler-in-a-Box biomass Heating oil Residential firewood

46 Critical infrastructure Aniquin School City Building Elim Native Store (two locations) Post Office / IRA Office Mukluk Telephone / TeleAlaska Building Johnny s Corner Store GCI Water Treatment Plant Fire Department Health Clinic Airport Well House Tank Farm AVEC Power Plant Septic Tank Head Start City Shop Church Boys & Girls Club Library Corporation Building From Elim Hazard Impact Assessment, HDR Alaska, Inc., February 2012.

47 Economic Dev t Plan Priorities 1. New Water Source 2. Develop Rock Quarry 3. Water & Sewer to 4 New Homes 4. Community Building (Old High School) 5. Utilize Our Timber 6. Build Small Boat Harbor 7. Economic Development Mineral, Geothermal, Hydrothermal 8. Teen Center 9. NSEDC Community Energy Fund (CEF) 10. Replace Old Bridge As identified in Elim Local Economic Development Plan: ; Kawerak, Inc.; 25 April 2013.

48 Space Heating Retrofit Considerations Changing the fluid temperature that is used for heating could affect the amount of baseboards a building requires Traditional boilers generally circulate fluid at about 180 degrees F As a general rule of thumb, in order to circulate 140 degree F fluid, about twice as much baseboard could be needed to achieve the same amount of heat output

49 Greenhouses What crops to raise? Local use and/or external market Fresh and/or preserved (can, dry) Growing conditions Sunlight, irrigation, fertilizer, soil, temperature, humidity, ventilation Pest & disease control Simple design with active on-site care Cooperative or private or?

50 Piping considerations Routing options: on-surface or buried Pressure drop: siphon or pumped Heat loss: insulated (how much, if any) Costs: materials, shipping, installation, energy for operation, maintenance Ground stability Interference with community & wildlife use

51 Soil considerations for pipe routing Permafrost Frost heave Hydraulic conductivity Bedrock depth Erosion Stability Future use

52 Miscellaneous considerations Hot spring attributes: temperature, flow rate, seasonal variation Permitting Surface / ground water flows & storage Effects on local plants and wildlife Pipeline costs (material, installation, repair) & losses (pressure, heat) Energy requirements (pumps, treatment) Maintenance (filters, line repair, quality test) Permafrost impact

53 Elim-area hot springs chemistry

54 Key Drilling Equipment Drill bits designed to penetrate dirt and rock A tracked drill rig would likely be needed to navigate unimproved trails. Drill rod is connected to feed the bit into the hole

55 Possible Drilling Steps Transport rig, drill rod, casing and other equipment to the drill site. Other equipment could include mud system, heavy equipment and so forth. Proceed to drill hole; for a small diameter hole, an exploration hole could likely be turned into a production hole by running casing onto the hole if temperature and flow are suitable. Other considerations include accommodations for workers, logistics for the delivery of supplies on site, and getting equipment across streams if necessary. Casing (approx. 6 in diameter) is required to line the hole once it is drilled An example of a larger drilling operation at Pilgrim Hot Springs

56 Cooperative Extension Service Main website: NW CES office: Kari van Delden Publications & Media Catalog Agriculture and Horticulture Community Resource and Economic Development Energy Education and Housing Health, Home and Family Development Points of Contact, Websites, Other Resources

57 Tenakee Springs Surface temperature: F Flow rate: TBD gpm Long time community-use soaking tub with oil-heat dressing room Updated in as community volunteer effort + Rasmuson Foundation Tier 1 Community Grant: Cleared / collected seeps, refurbished tub, replaced oil furnace with water-heated floor in dressing room (selectable gravity or pumped flow), added floor heat to adjacent warehouse building Images & information from: Direct Use: Pool Hot Tub - Bathhouse

58 White Bear Hot Springs Geothermal water is piped ¼ mile to remote 1970 s era multiroom cabin and used for space heating Temperature at source:~140 F Natural flow from spring:70 gpm ¼ mile of on-ground insulated 4-inch PVC pipe Gravity feed, no pump required After the water is used for heating, it is discharged into its natural drainage area. Direct Use: Space Heating

59 Midland, South Dakota (1/2) Population: 250 Began as source of heat for the school and eventually expanded to other community buildings and a swimming pool Initially in 1960 s, the well was drilled on a hill outside of town. Later in 1969 a well was drilled next to the school. Temperature at source: 152 F Flow rate: 180 GPM Well flows high pressure artesian, no pump needed. 30,000 square feet heated around town Lund, J., J. Nemec, and R. Vollmer. "Midland, South Dakota geothermal district heating." TRANSACTIONS- GEOTHERMAL RESOURCES COUNCIL (1998): Direct Use: Space Heating

60 Midland, South Dakota (2/2) Geothermal water is divided into high pressure (100 PSI) and low pressure (~20 PSI) lines. Fluid runs through PVC pipe. The high pressure line uses 80 GPM and loses 7 deg F as it heats the buildings The low pressure line uses 3 GPM and loses 25 deg F The waste geothermal water is used to water cattle, before being disposed of into the Bad River on the edge of town.

61 Pilgrim Hot Springs Status

62 Why Low-Temp Geothermal is Economic in Alaska (versus Iceland) High energy costs (typically over 50cents/kWhr in rural areas) Non-integrated electric grid (communities have their own generation sources) Cold climate (improves cycle efficiency)

63 Pilgrim Hot Springs Innovative Geothermal Exploration Techniques April 2011 Airborne FLIR (1m pixels) 100m Church Optical and infrared (FLIR) cameras Potential for rapid, lowcost mapping and quantitative assessment Funded through DOE and State of Alaska Verification using standard geothermal exploration techniques

64 Nome, AK: Pilgrim Hot Springs Images from Chena Hot Springs Resort

65 Nome Energy Facts.37/kW

66 Integration Modeling for City of Nome How does 2 MW of geothermal generation interact with existing wind and diesel generation sources? Is this project economic under reasonable cost projections?