Deep Underground, a New Clean Energy Contender Emerges

Early pilots in California suggest enhanced geothermal may deliver steady clean electricity to support wind and solar growth

6 Feb 2026

A pilot project in northern California is testing whether enhanced geothermal energy can move from an experimental concept to a dependable source of clean electricity for US power grids.

The project, in Sonoma County, forms part of the GeoZone initiative led by Sonoma Clean Power, a community choice electricity provider. It aims to show whether enhanced geothermal systems can supply round-the-clock power that could eventually displace fossil fuel generation and support grids with rising shares of wind and solar.

Interest in such technologies is growing as utilities seek firm clean power that does not depend on weather conditions. Solar and wind now account for a rising share of US electricity generation, but their variability has increased the need for resources that can operate continuously.

Enhanced geothermal differs from conventional geothermal power, which depends on naturally occurring underground reservoirs of hot water or steam. Instead, water is injected into hot rock deep below the surface, where it absorbs heat before being brought back up to generate electricity. Supporters say this could allow geothermal power to be developed in far more locations than is currently possible.

Chevron is leading development of the Sonoma County pilot, while Baker Hughes is providing drilling, monitoring and subsurface technologies. Their participation reflects growing interest from large energy companies, though commercial deployment remains limited.

The US Department of Energy is backing similar projects through competitive funding programmes designed to assess whether enhanced geothermal can be developed safely, at reasonable cost and at scale. Department officials say the aim is to determine whether the technology can deliver reliable and flexible clean power across a wider range of regions.

For utilities, the appeal lies in the potential for constant output, lower emissions and reduced reliance on imported fuels. Local authorities also point to possible benefits such as improved air quality and more stable electricity costs.

However, obstacles remain. Enhanced geothermal projects face high upfront drilling costs and regulatory scrutiny, particularly over the risk of induced seismic activity. Developers argue that advances in drilling techniques and monitoring, combined with lessons from early pilots, could help address these concerns.

Projects such as the one in Sonoma County are unlikely to reshape energy systems in the near term. But they are being closely watched as indicators of whether enhanced geothermal can become a meaningful part of a more resilient, low-carbon power system.