705°F superhot rocks could dethrone fossil fuels forever, offer clean power

As the world shifts towards renewable energy, geothermal energy emerges as a game-changing source hidden beneath the earth’s surface.

Typical geothermal power plants harness heat from the Earth’s surface. But now, scientists are turning their attention to a more powerful source: superhot rock.

A new report by Cornell researchers and the Clean Air Task Force (CATF) highlights the potential of superhot rocks as a significant renewable energy source. This could provide abundant, reliable, and cost-effective power.

The report notes that advanced technologies could make superhot rock energy accessible for geothermal systems in any location.

“Geothermal energy can offer an inexhaustible, always-available source of clean energy,” the report states.

“With innovation, superhot rock energy could have the potential to provide long-term, scalable, renewable baseload power in many more places around the world at a scale and cost equivalent to fossil fuels.”

Tapping into superhot rocks

Traditional geothermal energy sources are limited to areas with high heat flow near the Earth’s surface — typically near tectonic plate boundaries.

However, newer technologies aim to make geothermal energy accessible in more locations by tapping into superhot rock energy.

Superhot rocks are rocks located deep within the Earth’s crust, which are heated to temperatures exceeding 374 degrees Celsius (705.2°F).  This extreme heat makes them a potential source of geothermal energy.

Superhot rock systems involve drilling deep into the Earth’s crust. Water is injected into these hot rocks, heated, and then returned to the surface as steam. This steam can be used to generate electricity or produce hydrogen.

In 2022, Cornell University drilled a 2-mile deep exploratory well to study the potential of this geothermal energy source. But to tap into superhot rock energy, drilling depths of at least 6 miles are required.

To safely access superhot rock energy, the report highlights the need to select sites and understand their subsurface conditions carefully.

Geothermal projects heavily rely on detailed information about temperature, stress, water flow, and rock properties, which can change as the system operates.

Need for advanced drilling machines

The report highlights that accessing superhot dry rocks requires drilling deep into hard rock formations.

While existing technologies from geothermal and oil and gas industries can be adapted, significant advancements are needed in drilling equipment and techniques to reduce risks and improve efficiency.

“Unlike other readily scalable renewable energy technologies, the highly site-specific aspects of geothermal power production introduce risk that has been a major obstacle to commercial development,” said Seth Saltiel, the report co-author, in the press release.

He added: “By identifying state-of-the-art technologies and opportunities for research and development to improve and validate characterization methods, we hope to help overcome these obstacles and speed commercial development of this technology.”

Several companies are exploring the potential of superhot rocks as a major source of geothermal energy.

Recently, a US-based company, Quaise Energy, called these superdeep rocks “geothermal’s holy grail.” Their recent laboratory study validated the potential of these untapped resources.

The study revealed that superhot rocks can develop interconnected fractures. These fractures are essential as they allow water to flow through them and reach extremely high temperatures, exceeding 400°C (752°F), transforming it into a supercritical state.

Quaise Energy aims to harness the Earth’s core’s vast energy by developing innovative drilling technologies.

The new report is titled: “Gaps, Challenges, and Pathways Forward for Superhot Rock Energy.”