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Conference Proceeding

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National Renewable Energy Laboratory

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The U.S. Department of Energy (DOE) Geothermal Technologies Program (GTP or “the Program”) conducted a detailed risk analysis of their annual research, development, and demonstration (RD&D) portfolio. The Program worked with the National Renewable Energy Laboratory (NREL) to implement a probabilistic risk analysis of the GTP-sponsored RD&D, primarily enhanced geothermal systems (EGS) in accordance with Program budget authority. EGS technologies are in the early stages of development, and GTP-sponsored, multi-year demonstration projects are now underway to demonstrate technical feasibility, reduce risk for industry, and improve EGS best practices. The risk analysis examined estimates of improvement potential for two metric types: EGS-enabling technologies potential and EGS cost-improvement potential. NREL also evaluated potential improvements in hydrothermal exploration. The analysis employed a spreadsheet add-in that uses Monte Carlo simulation in conjunction with the Geothermal Electric Technology Evaluation Model (GETEM). Four risk groups (exploration, wells/pumps/tools, reservoir engineering, and power conversion) comprised of industry experts, national laboratory researchers, academic researchers and laboratory subcontractors estimated the RD&D impacts using probability distributions for three budget levels and two future time frames. Risk results were expressed in terms of each metric’s units and input into GETEM to estimate impacts on levelized costs of electricity. The resulting detailed risk analysis summarizes the industry’s current thinking on various metrics and potential for research improvement. Although the well drilling/construction and plant capital costs are key targets for cost reduction, all experts believed (1) that RD&D needs to occur first in enabling technologies for EGS and (2) that Program RD&D funding should not all be spent in only a few areas.


Energy analysis; Enhanced geothermal systems; Geothermal energy; Geothermal Electric Technology Evaluation Model; Risk analysis


Oil, Gas, and Energy




Presented at: 35th Stanford Geothermal Workshop, 1 February 2010, Stanford, California.
NREL Report No. CP-6A2-47388