U.S. geothermal capacity could hit 60 gigawatts by 2050, up from 3.8 GW today, if technology improvements drive down costs, according to a report by the Department of Energy.
The report — GeoVision: Harnessing the Heat Beneath Our Feet — lays out a framework for spurring the geothermal sector.
The geothermal industry is at the same stage the oil and gas sector was at when unconventional oil and gas reserves were known, but the technology to produce them economically didn’t exist, according to the report.
“To grow as a national solution, geothermal must overcome significant technical and non-technical barriers in order to reduce cost and risk,” Susan Hamm, director of DOE’s Geothermal technologies Office, said in an introduction to the report.
The top barrier facing the geothermal sector is underground exploration, which is expensive, complex and risky, Hamm said.
Other key challenges include acquiring power purchase agreements, land access and permits as well as interconnecting to the grid and getting financing, according to the report.
DOE said only a fraction of the geothermal resources in the United States has been tapped. Also, growth in the sector has been slight. There is 3.84 GW of geothermal capacity, representing 0.3 percent of total generating capacity, up from 3.37 GW in 2011, according to the Federal Energy Regulatory Commission.
Geothermal resources are concentrated in the West, with Nevada getting 8 percent of its electricity from geothermal facilities, followed by California with 6 percent.
Among its advantages, geothermal energy offers baseload renewable generation with flexible and load-following capabilities that provide essential services contributing to grid stability and resiliency, DOE said.
However, geothermal projects face high capital costs, according to the report. The cost for conventional geothermal projects range from $3 million per megawatt to $6 million/MW compared with $1.7 million/MW to $2.1 million/MW for land-based wind and utility-scale solar, DOE said, citing a 2016 report.
In the report, DOE looked at three types of geothermal resources: hydrothermal resources that are naturally occurring; enhanced geothermal systems; and geothermal heat pumps.
Under a business-as-usual scenario, DOE estimated that 3.5 GW of geothermal capacity could be added by 2025. Speeding up the permitting process could spur the development of 13 GW of geothermal capacity, according to the report.
Improved technology, especially for enhanced geothermal, could lead to more than 60 GW of geothermal, DOE said.
Also, technology gains could spur more than 17,500 geothermal district-heating installations nationwide and 28 million households could use geothermal heat pumps, according to the report.
DOE called for action in four areas to facilitate geothermal development, including research on resource assessments, improved site characterization and technology.
“The geothermal industry would benefit from technology breakthroughs in non-invasive, lower-cost geophysical and remote-sensing technologies,” DOE said.
DOE also recommended regulatory changes to improve access to land and project development.
“Overcoming complexity and uncertainty in costs and development timelines resulting from regulatory processes can support increased geothermal deployment,” DOE said, noting that 90 percent of conventional geothermal resources are on federal land.
The value of geothermal energy could be increased by making sure geothermal resources are paid for all the benefits they provide, according to DOE.
“Leveraging ‘always-on’ and broadly available geothermal resources can provide a range of benefits, including grid stability, reliability, and resiliency; efficient residential and commercial heating and cooling; environmental improvements; and geothermal industry growth,” DOE said, adding that the benefits aren’t always recognized in the market.
Finally, DOE called for increased stakeholder collaboration.
“Collaboration across geothermal stakeholders can help develop and establish a consistent, credible, and compelling message,” DOE said.
The report is online at: https://www.energy.gov/eere/geothermal/downloads/geovision-harnessing-heat-beneath-our-feet
