Harnessing Geothermal Power: A Pathway to Abundant Clean Energy If We Embrace It

Beneath the Earth’s surface lies a vast source of geothermal energy that has yet to be fully harnessed. This geothermal power has the potential to provide constant, carbon-free electricity, unlike intermittent sources such as solar and wind. A report presented at the World Geothermal Congress in 2021 highlighted that recovering just 1–2% of the thermal energy from hot rocks located 3 to 10 kilometers deep could satisfy global energy demands for many centuries. The geothermal gradient reaches an average of 25-30 degrees Celsius per kilometer, arising from the decay of radioactive elements and the Earth’s residual heat. Accessible geothermal resources in the U.S. are predominantly on federal lands in western states, but development has faced significant delays due to rigorous environmental reviews mandated by the National Environmental Policy Act—where up to six reviews were needed before project initiation—while oil and gas operations benefitted from categorical exclusions permitting expedited processes.

As of 2023, geothermal energy contributed only about 0.4% of total U.S. electricity, primarily from locations with surface steam in hot rocks. However, a report from the National Renewable Energy Laboratory suggests a potential capacity of over 4,200 gigawatts from tapping heat at depths between three and seven kilometers. This capacity dwarfs the current generation capacity of approximately 1,200 gigawatts. Various startups are actively working to overcome the technological challenges associated with accessing deeper geothermal energy. For example, Fervo Energy has commenced construction on a 400-megawatt enhanced geothermal power plant in Utah, expected to supply 320 megawatts to Southern California Edison, enough to power around 350,000 homes. Meanwhile, Canadian company Eavor is employing advanced drilling to establish a large underground closed-loop system in Germany that will facilitate heat circulation to supply electricity and thermal energy for homes and businesses.

Other enterprises are venturing into even deeper geothermal energy extraction, targeting superhot rocks that exceed 400 degrees Celsius. This approach could yield up to ten times more energy than conventional geothermal systems. According to the Clean Air Task Force, developing merely 1% of the superhot rock energy in the U.S. could produce a staggering 4,300 gigawatts. The drilling required for this resource can range between six to nine miles deep, significantly deeper than most current operations. Notably, the deepest exploratory effort was the Kola Superdeep Borehole in the Soviet Union, which reached depths of 7.6 miles. Various U.S. companies are innovating drilling techniques resilient enough to handle high temperatures, starting in volcanic zones closer to the Earth’s surface.

Hephae Energy Technology recently announced its Pandora210 drilling tool that operates effectively at temperatures up to 210 degrees Celsius and is working with Turkish geothermal company GMK Enerji to apply this technology. Their ambitious goal is to deploy one million geothermal wells into superhot rocks globally by 2050. Concurrently, AltaRock Energy has partnered with Quaise Energy to utilize innovative millimeter-wave drilling technology. This method employs directed energy techniques to speed up drilling by melting and vaporizing rock, as opposed to traditional mechanical drilling. AltaRock is currently engaged in a project near Newberry Crater in Oregon, aiming for a generation capacity of 35 megawatts that could expand to a remarkable 2,500 megawatts, capable of powering 2.5 million homes.

Economically, superhot rock geothermal energy can offer competitive electricity rates, with estimated costs ranging between $20 and $46 per megawatt-hour. This pricing is favorable when compared to conventional energy sources such as natural gas and renewable options like wind and solar, which vary from $36 to $38 per megawatt-hour. Moreover, recent regulatory changes at the federal level signal an easing of prior barriers that stifled geothermal development. With these developments, the likelihood of geothermal power emerging as a significant contributor to the carbon-free energy landscape in the U.S. is increasingly plausible.

In conclusion, the journey to harness geothermal energy has seen significant advancements, particularly through innovative startup efforts and regulatory changes aimed at facilitating exploratory drilling. While conventional geothermal energy utilization remains modest, the nascent exploration for deeper, more efficient energy resources presents an exciting opportunity for sustainable and reliable energy generation. As companies continue to push the technological envelope and expand the understanding of geothermal energy potential, the prospects for a vibrant, carbon-free energy future anchored in geothermal power look brighter than ever. The collaborative efforts across companies and nations could yield a fundamental shift in how we approach energy production, marking geothermal power as a cornerstone of the renewable energy movement.