Department of Energy Launches $84 Million Geothermal Program

Geothermal energy has stalled in the United States. Though the country remains as of 2019 the world’s top producer of geothermal power, growth in new deployment has been stagnant for a decade.

In 2012, geothermal plants produced 15,562 gigawatt hours (GWh) of electricity. That’s just four percent lower than the total in 2021, which at 16,238 GWh constituted less than half of one percent of the U.S. energy mix. 

 

Geothermal power has stalled in the U.S. Image used courtesy of the DOE

 

For the DOE, that’s a problem — the agency is targeting 60 new GW of geothermal deployment by 2050, which it says could provide non-stop power to 129 million homes and businesses. 

And to get there, it’s banking on serious development in enhanced geothermal system technology. 

 

What Are Enhanced Geothermal Systems? 

The DOE is planning to support four enhanced geothermal systems (EGS) pilot projects with the $84 million earmarked for geothermal development in the Bipartisan Infrastructure Law (BIL). 

EGS is, in theory, the answer to the capped potential of traditional geothermal systems, which utilize reservoirs of dry steam or hot water and are severely limited by geography. The Geysers steam field in northern California, for instance, is the only viable dry steam resource in the country. Hot water reservoirs are more common, though they are far from ubiquitous, with active plants operating in just a handful of states. 

But at depth in the earth’s crust, what is ubiquitous is hot rock. And an EGS is man-made. 

Using a drill, developers bore into hot rock to create an injection well. Cold water is then shot down the well at sufficient pressure, fracturing the rock into a network of small fissures, which despite its lack of standing water is also referred to as a reservoir. There, the rocks’ in situ heat warms the water as it flows to a drilled production well, which then pumps it to the surface for steam production. 

 

An EGS. Image [modified] used courtesy of the DOE

 

That is, in theory.

 

Tremendous Promise, Limited Development 

According to a 2006 panel report prepared for the DOE by the Idaho National Laboratory, with just modest investment EGS could provide 100 GW or more of generating capacity by 2050. That constitutes 9% of the installed capacity in the U.S. as of 2021, and 8% of projected capacity per the DOE’s release. 

“The U.S. has incredible, untapped geothermal potential beneath our very feet, which can be harnessed to meet our energy demands with a round-the-clock, clean renewable resource available across the country,” said Jennifer M. Granholm, the U.S. Secretary of Energy.

But that assumes the systems are viable at scale. And after nearly 50 years of research and development across four continents, they have yet to be proven so. 

Per an April 2021 report published by the Lawrence Berkeley National Lab and prepared for the DOE’s Office of Energy Efficiency and Renewable Energy (EERE), pilot projects in North America, Europe, Asia, and Australia have successfully generated electricity with EGS. But none have produced power at commercial levels, either due to insufficient circulation rates or premature thermal decline. 

 

Hundreds of Millions in Federal Funding for R&D  

Though the DOE is under no obligation to issue, through the EERE, a funding opportunity announcement (FOA) following its RFI, the BIL’s $84 million allocation runs only through 2025. Assuming the program proceeds with grant awards before that deadline, the four pilot projects will join an expansive portfolio of federally-funded initiatives targeting EGS development. 

Last February, the DOE announced that its Frontier Observatory for Research in Geothermal Energy (FORGE) initiative, based at the University of Utah, had selected 17 proposals to receive up to $46 million in funding to develop new EGS projects. In 2018, the DOE awarded the University itself $140 million to establish its underground EGS laboratory in Beaver County, the first of its kind. 

 

The FORGE site in Beaver County. Image used courtesy of the University of Utah

 

Other projects from the DOE include the $27 million EGS Collab, a $20 million investment to reduce the cost of geothermal drilling, and a $3.5 million funding opportunity for projects developing machine learning to enhance EGS exploration and production. 

Still, until these and the announced pilot projects prove viable at the commercial level, EGS will remain untapped.

To participate in this latest RFI, stakeholders looking to realize the technology must submit responses via email no later than 5 p.m. ET on May 13. 

 

Feature image [CC BY-SA 3.0] used courtesy of Ásgeir Eggertsson