Competition for water use in utility-scale solar power

Transcription

1 Competition for water use in utility-scale solar power Ground Water Protection Council 2011 Annual Form Atlanta, GA September 24-28, 2011 Jordan Macknick Craig Turchi Michael Wagner Mark Lausten National Renewable Energy Laboratory Golden, Colorado NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy operated by the Alliance for Sustainable Energy, LLC

2 National Renewable Energy Lab (NREL) U.S. Department of Energy Research Laboratory Only laboratory to exclusively study renewable energy and energy efficiency Existing research identifying energy issues in the water industry Existing research identifying water issues in the energy industry 2

3 Concentrating Solar Power (CSP) Technology types Power tower Parabolic trough Linear Fresnel Dish/Stirling

4 CSP technologies with thermal energy storage are dispatchable like conventional electricity generating technologies Thermal energy storage systems with molten salts allow electricity to be generated when the sun is not shining Photo courtesy Solar Millennium AG Electricity can be dispatched when it is needed most throughout the day 4

5 CSP cooling technology options Wet Cooled (Cooling Towers) Dry Cooled (Air Cooled Condensers) Hybrid Cooled (Both cooling towers and air cooled condensers) 5

6 Climatic conditions affect CSP performance and cooling technology performance Hotter areas will lead to lower thermal efficiencies These performance penalties are more pronounced when switching to dry cooling 100% 99% 98% Effect of location on plant output for different cooling technologies 97% 96% 95% Wet Cooling Hybrid Cooling Dry Cooling Implications for reliability of CSP systems in extreme weather conditions Adapted from Turchi et al. (2010) 94% 93% 92% Las Vegas, NV Alamosa, CO 6

7 Climatic conditions affect CSP costs of energy generation Compared to wet-cooled System, LCOE increase ranges from 2.5% to 7.5% LCOE increase vs. wet-cooled Design 8.0% 7.0% 6.0% 5.0% 4.0% 3.0% 2.0% 1.0% 0.0% Adapted from Turchi et al. (2010) Alamosa Las Vegas, no TES Las Vegas Daggett 7 TES: Thermal Energy Storage Dry Hybrid Wet

8 Operational water consumption factors for electricity generating technologies gal/mwh TOP LINE FINDING Recirculating Cooling Once-through Cooling Pond Cooling Dry Cooling Hybrid Cooling No Cooling Required Caption or heading (if you have one) (insert really cool image/supergraphic from your work) CSP and PV Biopower Nuclear Natural Gas Coal Source: Macknick et al. 2011

9 Water Supply Constraints Coincide with Best CSP Plant Locations in the US Water Sustainability Index - EPRI S.B. Roy, K.V. Summers, and R.A. Goldstein, Water Sustainability in the United States and Cooling Water Requirements for Power Generation, Universities Council on Water Resources Water Resources Update, Issue 126, Pages 94-99, November Projected CSP deployment in US (in progress) 9

10 Future of CSP in the Southwest: Solar Energy Development Programmatic EIS (PEIS) 24 Solar Energy Zones developed by the Bureau of Land Management (BLM) and Department of Energy (DOE) -~ 21 million acres of BLM land could be available for CSP -By 2030, 24 GW of solar on 200,000 acres of BLM land Source: Argonne National Laboratory 10

11 Regional Energy Deployment System (ReEDS) Model Description ReEDS: Linear program minimizing overall electric system costs 134 Power Control Areas 356 Solar and Wind Resource Regions Constraints: Electricity demand Reserve requirements Regional resource supply State and Federal policy Transmission 17 annual time slices 11

12 Electricity Demand and Generation Projections in 2030 TWh Generated 5,000 4,500 4,000 3,500 3,000 2,500 2,000 1,500 1, Present 2030 Wind CSP PV Geothermal Landfill gas Co-fire Biopower Nuclear Coal Natural Gas Hydropower Change in generation (MWh) < > Generation increases 21% from 2006 to Most new generation is from renewables and natural gas Source: Macknick et al., in progress 12

13 Water impacts in 2030: Withdrawals Changes in water withdrawals from today s withdrawal amounts are highly regionalized Change in Withdrawals (m 3 ) < > 10 9 Change in Withdrawal Rate (m 3 /GWh) < -10,000-10, ,000-1, ,000 1,000-10,000 > 10,000 Source: Macknick et al., in progress 13

14 Water impacts in 2030: Consumption Changes in water consumption from today s withdrawal amounts are highly regionalized Change in consumption (m 3 ) < > 10 7 Change in Consumption Rate (m 3 /GWh) < -1,000-1, ,000 > 1,000 Source: Macknick et al., in progress 14

15 CSP Deployment and potential water impacts Wet-cooled CSP Percent of Total Generation % Consumption <0 <0% >50 >25% Dry-cooled % Consumption Where will water for these facilities come from? <0 >50 Source: Macknick et al., in progress 15

16 Total Freshwater Withdrawals by Sector for the Southwest 40 Freshwater Withdrawals in 2005 (USGS) 35 Million Acre-Feet per year Thermoelectric Mining Industry Aquaculture Livestock Irrigation Domestic Public Supply 5 0 Arizona California Colorado Nevada New Mexico Texas Utah National Average : Thermoelectric = 41% of total freshwater withdrawal Southwest Average: Thermoelectric = 12% of total freshwater withdrawal Southwest sans Texas: Thermoelectric = <1% of total freshwater withdrawal

17 Total Freshwater Consumption by Sector for the Southwest 30 Freshwater Consumption in 1995 (USGS) 25 Million acre-feet per year Thermoelectric Mining Industry Livestock Irrigation Domestic Commercial 5 0 Arizona California Colorado Nevada New Mexico Texas Utah 17

18 CSP can be less water intensive than other irrigated agricultural lands in the Southwest Arizona California Colorado Nevada New Mexico Texas Utah CSP (wet cooling) CSP (Dry cooling) Acre-ft of water per acre of planted irrigated land Source: USDA Economic Research Service (ERS), 2004

19 CSP technologies have lower water use per land area than many other land-uses Acre-ft / acre per year CSP (wet_cooled) CSP (dry_cooled) PV Alfalfa Cotton Fruit Trees Golf Courses Sources: CSP: Reducing Water Consumption of CSP Electricity Generation, Report to Congress Crops: Blaney, Monthly Consumptive use of Water by Irrigated Crops & Natural Vegetation, Golf : Watson et al., The Economic Contributions of Colorado s Golf Industry: Environmental Aspects. Courtesy: Craig Turchi, NREL

20 Potential impacts of conflicts Food vs. Fuel debate intensifies Agriculture output in Southwest declines Agriculture output in other regions increases Delay in solar energy installations Debate over local benefits to community State-level legislation governing water usage in CSP plants Water rights/availability as limitations to growth in the electricity sector

21 Opportunities to minimize potential for conflicts Cooling system research Dry and hybrid cooling Shallow brackish water Reducing cost and performance penalties Improving agriculture water use efficiency Outreach programs Energy-agriculture partnerships Co-location of agriculture and energy Test pilots in MA, CA, and WI Agricultural research

22 Conclusions CSP is likely to have a strong regional role in electricity portfolios in the Southwest Some CSP configurations can consume substantial amounts of water, which may conflict with other water uses By many metrics, CSP consumes less water per unit of area than other agricultural uses in the Southwest To meet state and national level renewable energy goals with CSP, water may be required from the agricultural sector Integrated energy and water planning is essential to meet energy policy goals while maintaining sustainable water supplies

23 Thank you Jordan Macknick (303) National Renewable Energy Laboratory Golden, Colorado NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy operated by the Alliance for Sustainable Energy, LLC