The coronavirus pandemic has mostly yielded bad news for renewable energy. Disruptions to supply chains and slowdowns in permitting and construction have delayed solar and wind projects, endangering their eligibility for the soon-to-expire investment tax credits they rely on. There’s another form of renewable energy, however, that might see a benefit from the recent global economic upheaval and emerge in a better position to help the United States decarbonize its electricity system: geothermal.
Geothermal energy comes from heat beneath the earth’s surface that we can tap into to generate electricity and to heat and cool our buildings. In a report released last year detailing the growth potential of geothermal energy, the Department of Energy called it “America’s untapped energy giant.”
Unlike wind and the sun, subsurface heat is available 24/7, perpetually replenished by the radioactive decay of minerals deeper down. But compared to wind and solar farms, geothermal power plants are expensive to build. The cost can range from $2,000 to $5,000 per installed kilowatt, and even the least expensive geothermal plant in the U.S. costs more than double that of a utility-scale solar farm. Engineers have to drill thousands of feet into the ground to reach reservoirs of water and rock hotter than 300 degrees F in order for the plants to be economical. Plants generate electricity by pumping steam or hot water up from those reservoirs to spin a turbine which powers a generator.