PNNL

Abstract

An optimized hybrid energy system is important for a resilient U.S. energy grid. Energy demand and production follow seasonal or daily cycles, necessitating the development of a weather-informed hybrid energy system that leverages the strengths of individual energy sources. Wind power is a cheap yet variable source of electricity. Here we use observed U.S. wind generation rates and the latest geothermal estimates to understand the possibilities of co-locating geothermal with existing wind farms. Wind farm generation rates of 592 wind farms are analyzed, quantifying the collective generation ‘gap’ required to increase each wind farm’s (2024) monthly electricity generation rate up to its respective annual monthly maximum. The latest Enhanced Geothermal System (EGS) estimates from the Stanford Thermal Model are then geographically paired with each wind farm location, yielding the co-located EGS resource potential and cost. Results show that EGS generation rates over an area of 1km2 are sufficient to fill-in for variable wind generation for 55% of all U.S. wind farms, increasing to 100% of U.S. wind farms if 10% of the wind farm’s footprint is available for EGS. Levelized Cost of Energy (LCOE) of EGS at wind farm locations are lowest in the West and along the southern Texas border and broadly highest in the Central US where the most expansive and powerful wind farms reside. With no operational EGS powerplants in the U.S. and none at the necessary multi-MW scale theorized here, more experiments and test are clearly warranted. Still, the potential for wind + EGS to generate more power from the same land footprint, while also maximizing the use of existing electrical infrastructure seems worthy of more research.