Geothermal Energy: The Next Frontier for the US is Clean, Reliable Power

Building a clean, reliable, and cost-effective power grid requires a mix of energy sources. While solar and wind energy will dominate, they aren’t available 24/7, 365 days a year. That’s where clean, “firm” power sources—like geothermal, nuclear, and hydropower—come into play. Among these, geothermal energy is gaining attention due to recent technological advancements that make it more accessible and affordable.

Geothermal energy currently supplies less than 1% of the world’s electricity, but next-generation technologies could revolutionize this sector. According to the U.S. Department of Energy (DOE), geothermal energy capacity in the U.S. could grow from 4 gigawatts (GW) today to 90 GW by 2050—and potentially even 300 GW under high-end projections. These advancements could expand geothermal’s reach from just seven states to at least 18 across the U.S., offering a critical tool in achieving a zero-carbon energy grid.

The Promise of Next-Generation Geothermal

Traditional geothermal energy has been used for over a century but has remained geographically limited. It relies on tapping into natural underground reservoirs of hot water, which are only available in specific locations like Kenya, Iceland, Indonesia, and parts of the western U.S.

Next-generation geothermal technologies, however, aim to harness Earth’s heat without needing natural reservoirs. This breakthrough could unlock vast amounts of clean energy worldwide.

According to DOE estimates, by 2050, geothermal energy could provide roughly a quarter of the U.S.’s total electricity capacity. The advancements are not merely theoretical—several projects are already underway. Companies like Fervo Energy are developing commercial Enhanced Geothermal Systems (EGS) in Nevada and Utah, while others like Eavor are testing closed-loop geothermal systems in Canada and Germany.

How Next-Generation Geothermal Works

Three types of next-generation geothermal technologies are leading the charge:

1. Enhanced Geothermal Systems (EGS)
   EGS creates artificial underground reservoirs by drilling into hot rock and using hydraulic fracturing to create cracks. Water is injected into one well, heated as it flows through the rock, and pumped up another well to generate power. DOE-funded projects like the FORGE initiative in Utah have been instrumental in advancing EGS technology.
2. Closed-Loop Systems
   Unlike EGS, closed-loop systems don’t rely on creating underground reservoirs. Instead, they use sealed wells to circulate fluids that never come into direct contact with surrounding rocks. The company Eavor has demonstrated this technology successfully in Canada and is now developing its first commercial project in Germany.
3. Superhot Geothermal Systems
   These systems aim to tap into extremely hot rock environments exceeding 374°C, where water becomes “supercritical” and holds far more energy. Companies like Quaise Energy and GA Drilling are exploring technologies to access these extreme conditions, which could theoretically meet global electricity demand if successful.

Environmental Benefits of Geothermal Energy

Geothermal energy is a clean, low-emission power source with several environmental advantages:

• Minimal Greenhouse Gas Emissions: On par with solar and wind, geothermal energy is a reliable, carbon-free option to supplement intermittent renewables.
• Low Land and Water Use: Geothermal plants require less land than other energy sources like wind and solar and use less water than coal, nuclear, or hydropower.
• Fewer Critical Mineral Dependencies: Unlike battery technologies, geothermal energy requires fewer critical minerals like lithium or zinc.

Additionally, geothermal plants produce little to no conventional air pollutants, avoiding health risks like lung and heart disease often associated with fossil fuel plants.

Addressing Risks

Concerns about seismic activity and water contamination have been raised, particularly in relation to EGS projects, which use hydraulic fracturing. However, the DOE’s Induced Seismicity Protocol has successfully prevented earthquake-related issues in geothermal projects for over a decade. Moreover, unlike oil and gas fracking, EGS uses little to no chemical additives, and underground systems are sealed to prevent groundwater contamination.

Despite these safeguards, risks remain, especially near natural fault lines. Incidents in France, Switzerland, and South Korea highlight the importance of robust monitoring and site selection.

Geothermal’s Cost Competitiveness

The cost of geothermal energy is falling rapidly. At the DOE FORGE site, drilling costs have dropped by 500% since 2017, and Fervo Energy reduced drilling costs from $1,000 per foot to $400 per foot between projects. According to the DOE, EGS projects could cost $64 per megawatt-hour (MWh), making them competitive with solar-plus-battery systems.

The Future of Geothermal

With advancements in EGS, closed-loop systems, and the potential for superhot geothermal, this energy source could become a cornerstone of the global clean energy transition. Major tech companies and utilities are already investing in geothermal projects, signaling a bright future for this next-generation technology.

Geothermal energy offers an opportunity to scale up clean, firm power worldwide. With continued innovation, it could provide a critical bridge to a 100% clean, reliable power grid.

Source and Images: WRI.Org