In a breakthrough for geothermal energy, start-up Fervo Energy has developed an Enhanced Geothermal System (EGS) that can be used in areas where traditional geothermal power plants cannot operate due to impermeable rock. Geothermal energy is a CO2-neutral source of electricity and heat, but its use is limited by the inability to extract hot water from the earth’s interior in some locations. EGS technology has been under development since the 1970s to address this issue, but previous pilot projects have not been successful. Fervo Energy’s EGS project uses drilling techniques from the oil industry, including fracking and horizontal drilling, but only uses water instead of chemicals. The water is pumped into the ground through two 2.3-kilometer-deep holes connected by 990-meter-long horizontal boreholes. The high water pressure expands cavities in the rock, allowing the water to sink and be heated by the hot rock. The heated water is then pumped to the surface and used to generate electricity.
During a 30-day pilot project in Nevada, Fervo Energy achieved a flow rate of 63 liters per second, enough to power a 3.5-megawatt plant that can supply electricity to around 2,600 households in the U.S. This is a record flow rate and energy output for an EGS, and demonstrates that the technology is suitable for industrial use. Fervo Energy plans to build a 400-megawatt EGS power plant in Utah by 2028, which could supply electricity to around 300,000 households. The Nevada plant is expected to be connected to the grid by the end of the year.
This breakthrough in geothermal energy could have significant implications for the renewable energy sector, as it expands the potential locations for geothermal power plants. The use of water instead of chemicals in the drilling process also reduces the environmental impact of EGS technology. Fervo Energy’s success in developing a commercially viable EGS technology could pave the way for further innovation in the geothermal energy sector.
