Fervo Energy, a leading geothermal developer, has made headlines with a groundbreaking power purchase agreement (PPA) with tech giant Google. This deal, which is the largest of its kind to date, involves a commitment to provide 396 megawatts (MW) of carbon-free energy, facilitating the development of the Cape Station enhanced geothermal systems (EGS) GeoCluster. The project is anticipated to commence operations in 2028.
Under the terms of the agreement, Google will acquire renewable energy that is intended to serve as a crucial component for a prospective data centre in Utah. Furthermore, Fervo has included an option for Google to increase its energy offtake by an additional 600 MW, potentially bringing the total to nearly 1 gigawatt (GW) by June 2030. However, the finalisation of the data centre plans will depend on various factors, including engineering feasibility, local and state approvals, and commercial conditions.
Unlocking New Energy Capacity
Fervo has emphasised that this agreement will unlock new, continuous electricity capacity without imposing costs on existing ratepayers. Tim Latimer, CEO and co-founder of Fervo Energy, remarked, “This agreement reinforces that EGS is ready to power the next generation of computing infrastructure. As demand for reliable electricity grows, customers like Google need energy resources that can be deployed at scale, operate around the clock, and deliver where power is needed.” He expressed pride in collaborating closely with the communities in Southwest Utah and with a partner that shares their community-first values.
The partnership between Fervo and Google began with Project Red, a commercial pilot project in Nevada that became operational in 2023. This pilot project supplies power to the local grid, including Google’s data centres in Nevada. Following this, Fervo secured a 115 MW PPA with Google and NV Energy in June 2024, which played a pivotal role in pioneering the Clean Transition Tariff. This initiative allowed Google to integrate more geothermal energy into the Nevada grid while protecting customers from the associated costs.
Significance of the Cape Station Project
The Cape Station project represents a significant expansion beyond its initial 100 MW phase, as Fervo continues to scale its operations. It is recognised as the world’s largest enhanced geothermal systems (EGS) development, with plans to begin delivering electricity to the grid this year. The project encompasses Cape Station Phase I, which is set to provide 100 MW of clean baseload power starting in 2026, and Cape Station Phase II, which will add another 400 MW by 2028. The entire Cape Station development has received permits for up to 2 GW of reliable and renewable energy.
Unlike traditional geothermal systems that rely on naturally occurring hot water, the Cape Station project employs an enhanced geothermal system that generates energy by injecting water into hot subsurface rock formations and extracting the heated water to produce electricity. The project is expected to cover approximately 631 acres, with 148 acres designated on public lands.
Geothermal Potential in Utah
Utah is recognised for its substantial geothermal potential, with researchers estimating that the southwestern region of the state holds over 10 GW of high-quality geothermal reserves. The Cape Station project will also benefit from the Department of Energy’s Frontier Observatory for Research in Geothermal Energy (FORGE), which has conducted research over the years that has advanced geothermal development in the area.
Currently, the United States has approximately 4,000 MW of installed geothermal capacity, accounting for about a quarter of the global total. The majority of this capacity is concentrated in California (66.6% of the total U.S. geothermal generation in 2023) and Nevada (26.1%), with smaller amounts in Utah (3.2%), Hawaii (2.1%), Oregon (1.3%), Idaho (0.5%), and New Mexico (0.2%).
Future of Geothermal Energy
In a bid to enhance geothermal power production, the U.S. Department of Energy (DOE) Advanced Research Projects Agency-Energy (ARPA-E) announced a $30 million initiative aimed at unlocking “superhot” reservoirs deep within the Earth. The SUPERHOT programme is designed to provide access to superhot reservoirs capable of generating 10-20 GW of reliable baseload power at a competitive cost of less than $30 per megawatt hour (MWh) by 2040. As the demand for power surges in the U.S., driven largely by data centres and manufacturing, the DOE posits that expanding geothermal power production could play a vital role in meeting this demand.
Enhanced geothermal systems (EGS) and advanced geothermal systems (AGS) create engineered geothermal systems wherever hot rock exists, either by forming subsurface fracture networks or drilling extensive boreholes. However, the highest temperatures currently accessible are around 220 °C due to the absence of commercial equipment capable of handling higher temperatures. This limitation restricts EGS power production to approximately 10 megawatts-electric (MWe) per well site. The DOE maintains that accessing superhot reservoirs could significantly increase electrical output per well, potentially reaching 30-50 MWe as both subsurface heat availability and thermal-to-power efficiency improve.
High-temperature subsurface rocks are found in various locations, but their depth can vary significantly. In volcanic regions with a high geothermal gradient, such as parts of Hawaii, Alaska, and the West Coast, temperatures of 375 °C may be encountered at depths as shallow as 5 km. In other areas, drilling may need to reach depths of 10 km or more. While drilling wells deeper than 9 km has been feasible for decades in regions with lower geothermal gradients, none have yet reached superhot temperatures.
Previous efforts to harness geothermal power from superhot reservoirs have faced challenges. Approximately 20 vertical and near-vertical boreholes have been drilled to temperatures as high as 500 °C and depths of up to 5 km, but most of these wells failed rapidly, and none are currently producing power. Key challenges in constructing superhot wells include the high costs of performance metal alloys and materials required for extensive geothermal casing, the need for well-established installation procedures, and the extreme conditions faced by superhot geothermal technology, including high temperatures, corrosive fluids, and repeated thermal cycling.
Source: Renewable Energy World
