Fervo Energy has begun commercial operations at its Cape Station geothermal plant in Utah, completing construction in just 23 months. The plant started delivering power on September 30.

The first 33 MW GeoBlock is online out of a planned 100 MW first phase. The site has potential for up to 4 GW of capacity, which would make it one of the world's largest enhanced geothermal projects. Google and Southern California Edison are among the buyers.

Fervo uses horizontal drilling techniques borrowed from the shale industry to create geothermal reservoirs in hot rock. The approach promises firm, round-the-clock clean power in places without natural steam fields.

The 23-month build time is strikingly fast for a power plant. If Fervo can repeat the feat at scale, enhanced geothermal could become a major source of always-on carbon-free electricity. The company plans to replicate the design at other sites across the western United States. Utilities are watching closely as demand for firm clean power grows.