Geothermal development company Fervo Energy has announced impressive strides being made at its Cape Station facility in southern Utah. The results could lead to a quicker and more widespread uptake of this super-clean energy production process.
In a publication announced at the Stanford Geothermal Workshop this week, Fervo said it has been able to drill a horizontal well in just 21 days. That's a 70% reduction in drilling time over its first horizontal well, which was drilled in Nevada in 2022 as part of a Google-backed effort known as Project Red. The company says this reduction in time has led to an additional reduction of costs, with the latest well coming in at US$4.8 million, down from $9.4 million.
The new record is one in a series of strides Fervo is making to produce affordable, usable, clean power through a process using an enhanced geothermal system (EGS). Last year, Project Red passed its 30-day well test and was able to produce 3.4 megawatts (MW) of power, roughly the energy used by 500 US households. In November, Google announced that the plant was fully operational and connected to the same grid in Nevada to which some of Google's data centers are linked.
Fervo is now developing an even larger project in Utah that aims to come online in 2026, and reach its full capacity for pumping out 400 MW of non-stop power in 2028. The wells it is drilling there are even hotter and over 2,100 feet (640 meters) deeper than those from Project Red, so the faster drilling time is even more impressive.
The following video from the US Department of Energy provides a solid background on how EGS works. In a nutshell, though, the process involves drilling wells to inject water deep inside the ground. This breaks up solid rock so that water can circulate through it and get heated. That hot water is returned to a power plant, used to heat a working fluid which turns to steam, powers turbines, and produces electricity. The water is then recirculated and the process continues again.
To reach the new drilling speeds, Fervo utilized polycrystalline diamond compact (PDC) drill bits – normally used to cut through shale harboring oil and gas reserves – along with mud coolers, which are used in oil and gas drilling to keep rigs from overheating.
"We now have the best drilling technology from the petroleum drilling industry," said Fred Dupriest, commenting on the published work. Dupriest is a professor of engineering at Texas A&M University and former Chief Drilling Engineer at ExxonMobil. "What encourages me now is that we’re starting to learn how to use it in ways that specifically maximize performance. Performance isn’t just what you use, but how you use it. We’re not just achieving technology transfer, but an impressive rate of knowledge transfer in how to use it."
Source: Fervo Energy
