Enhanced geothermal systems promise wider access to clean energy

Historically, access to geothermal energy has hinged on real estate's famously three most important factors: location, location, and location. Because conventional geothermal power plants require hot, permeable rocks and plenty of underground fluid, use of the technology has been limited mostly to places with recent volcanism, such as Japan, New Zealand, the Philippines, Kenya, El Salvador, Iceland, and the western United States.

Over the past 50 years, however, techniques originally developed for oilfields and adapted for "enhanced geothermal systems" (EGS) have offered the promise of tapping deep reserves of natural heat across a broader swath of the planet.

"There is a lot of excitement about enhanced geothermal energy," said Roland Horne, a professor of energy science and engineering in the Stanford Doerr School of Sustainability, who convened more than 450 engineers, scientists, and managers from 28 countries earlier this month at the 50th Stanford Geothermal Workshop to exchange ideas and report results from projects around the world.

To date, nearly all EGS applications have been for research purposes in one-off, small-scale plants, said Horne, who was invited to gather a team of authors to write a review paper for the February 2025 issue of Nature Reviews Clean Technology about EGS and its potential to supply energy at a larger scale.

OP and further reading