_ The first geothermal power plant powered just a handful of light bulbs. That was more than 120 years ago. Since then, geothermal energy has advanced to become a major player in power generation. “Geothermal is actually a rather unique energy source, ” said Henning Bjørvik, head of renewables research at Rystad Energy, during the 2025 Offshore Technology Conference (OTC). “It is a clean and firm source. If you look at solar and wind, these are clean sources, but they are not firm. … I mean, a solar panel basically generates during daylight hours; wind turbines basically generate when you when have wind. So, you always have gaps that you have to deal with. ” Hydrocarbon-based energy, he added, is firm but not clean. Geothermal is clean and firm, working regardless of weather conditions, but its development has been hampered by geography and technology. Some parts of the world are blessed with favorable geothermal geology. As of 2025, the Icelandic Energy Authority reported that geothermal energy accounts for 60% of the country’s primary energy consumption. Of course, that’s in Iceland, where the heat and water needed for geothermal energy production is plentiful and near the surface. What about the rest of the world? The US has plentiful subterranean heat (Fig. 1), enough to generate at least 90 GW of geothermal electricity-generating capacity across the US by 2050, according to a US Department of Energy (DOE) analysis. Accessing it, however, is a challenge. Near Milford, Utah, the Frontier Observatory for Research in Geothermal Energy (FORGE) initiative is working on that challenge. The dedicated field site is funded by the DOE and managed by the Energy & Geoscience Institute at The University of Utah. FORGE is focusing on understanding the key mechanisms of enhanced geothermal systems (EGS). EGS uses wellbores to reach the underground heat and fractures to increase surface area for fluids pumped down the wells to collect that heat. Immediately adjacent to the FORGE site, Fervo is working on the multiphase Cape Station geothermal development, which it says could ultimately deliver 500 MW of power. Fervo says Phase I is expected to begin delivering power to the grid this year. Also funded by the DOE, the Geothermal Energy from Oil and Gas Demonstrated Engineering (GEODE) consortium is tackling the challenges of geothermal energy production. GEODE is led by Project InnerSpace and the Society of Petroleum Engineers. Project InnerSpace says on its website that, if drilling for geothermal energy were conducted at the rate it currently is for oil and gas, 77% of global demand for electricity could be met by 2050. Hard Rock Geothermal resources often exist in rock that is difficult to drill, such as hard granitic rock and abrasive volcanic rock. These environments can quickly chew up drill bits. Polycrystalline diamond compact (PDC) bits are often the preferred choice, but research has suggested that these, too, may be at the limits of their abilities. While conventional roller-cone bits degrade rapidly while chewing through hard crystalline granite, at the FORGE site, for instance, PDC bits have demonstrated increased durability and rates of penetration. Researchers are now looking at the geometry of the bits to boost these features.
Adam Wilson (Sun,) studied this question.