The U.S. Department of Energy (DOE) has selected 21 projects to share a $99-million funding to advance testing of next-generation geothermal technologies and exploration drilling to confirm promising geothermal resources across the country, Reuters reported.

Among the 21 projects, five will conduct field tests of enhanced geothermal systems, while 16 will focus on exploration drilling to identify promising resources.

Recipients include Fervo Energy, selected for two projects covering an enhanced geothermal systems demonstration in Idaho and exploration drilling in Nevada, alongside Quaise Energy, Zanskar Geothermal, XGS Energy and Invenergy.

The department said data generated under the projects will be made publicly available through its Geothermal Data Repository to guide future technology development and resource exploration.

"These projects will empower American innovators to unlock the tremendous geothermal resources beneath our feet," DOE Under Secretary of Energy Kyle Haustveit said in a statement.

Geothermal energy has become one of the fastest-growing areas of the U.S. power sector, as developers adapt oil-and-gas drilling techniques to tap underground heat for around-the-clock electricity generation, attracting growing interest from investors and energy companies.