Washington Geothermal Play Fairway Analysis Technical Report

An investment of $0.7M from the Geothermal Technology Office for Phase 2 of Play Fairway Analysis in Washington State improved existing favorability models and increased model confidence. New 1:24,000-scale geological mapping, 15 detailed geophysical surveys, 2 passive seismic surveys, and geochronology collected during this phase were coupled with updated and detailed structural modeling and have significantly improved the conceptual models of three potential blind geothermal systems/plays in Washington State, the St. Helens Shear Zone, Mount Baker, and Wind River Valley. Results of this analysis reveal the presence of commercially viable undiscovered geothermal resources in all three study areas. The analysis additionally provides a clear definition of the geothermal prospects in terms of the essential elements of a functioning geothermal system, the confidence in these assessments, and associated potential and risk of development.

This report also includes a proposal to validate the modeling results in highly favorable areas for two main reasons: (1) to develop confidence in the modeling approach that will encourage future development of geothermal resources in Washington State inside and outside of the Phase 2 study areas, and (2) to provide actionable results to the DOE, existing industry partners, newly identified developers, and other renewable-energy stakeholders. The proposed validation activities aim to collect new data that will further the understanding of geothermal resource potential in Washington, as well as substantiate the favorability, confidence, and risk models developed in Phases 1 and 2.