Energy source from super hot 374 degree C rock underground

Scientists study super-hot rocks at depths of nearly 10km as a potential renewable energy source to replace fossil fuels.

As the world shifts toward renewable energy, geothermal energy is gaining traction. Geothermal power plants typically harness heat from the Earth's surface. But now scientists are turning their attention to a more powerful source of geothermal energy: superheated rock.

Steam rises from an industrial geothermal power plant in Southern California, USA. (Photo: iStock).

A new report by a team from Cornell University and the Clean Air Task Force (CATF) highlights the potential of superheated rocks as an important renewable energy source, providing abundant, reliable, and cost-effective electricity , Interesting Engineering reported on December 9.

Traditional geothermal energy sources are limited to areas of high heat flow near the Earth's surface - usually near tectonic plate boundaries . However, new technology is making geothermal energy more accessible by harnessing the energy from super-hot rocks.

Superheated rock is rock deep in the Earth's crust that has been heated to temperatures exceeding 374 degrees Celsius. To mine it, you drill deep into the Earth's crust and pump water into the superheated rock. The water is heated and then returns to the surface as steam. The 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. However, to harness the energy from super-hot rocks, it is necessary to drill at least 6 miles deep.

To safely tap into the energy from superheated rocks, the team stressed that selecting the right location and understanding the conditions underground are essential. Geothermal projects rely heavily on detailed information about temperature, pressure, water flow, and rock properties. Significant advances in drilling equipment and techniques are also needed to reduce risks and increase efficiency.

'Unlike other renewable energy technologies that can be easily scaled up, geothermal power generation is highly location-dependent, which introduces a number of risks and is a major obstacle to commercial development. By identifying cutting-edge technologies and research and development opportunities, we hope to overcome these obstacles and accelerate the commercial development of this technology,' said Seth Saltiel, co-author of the new report.