The use of fossil fuels is not eternal, and we all know it. That’s why energy alternatives are being sought. Quaise Energy is a spin-off from the Massachusetts Institute of Technology (MIT) formed in 2020. It has an ambitious project. They plan the deepest hole in the Earth to extract geothermal energy.
This energy is obtained from the heat of the Earth’s interior. It is clean, continuous and unlimited. It is used in some areas of volcanic activity, such as Iceland: there the hot rock is much closer to the surface.
In the rest of the world, on the other hand, the geothermal source is far below. The deepest hole on the planet, the Kola borehole in Russia, is 12 km deep. Quaise plans to go well beyond this limit. To do so, excavation equipment must operate at more than 180 degrees Celsius (°C). This makes the rock behave more like a plastic than a solid.
Quaise wants to add a drilling method that does not require contact between the tool and the rock. This is the gyrotron. It produces millimeter waves of electromagnetic radiation to heat materials to the point of evaporation. They estimate that they will drill through up to 20 kilometers of the Earth’s crust in just over three months.
There the temperature is over 500 °C and the pressure is almost 200 megapascals (MPa). Water becomes a ‘supercritical’ fluid when it exceeds 374 °C and 22 MPa. In that state it returns as an infernal vapor to the plant, where it generates electricity.
“A power plant using supercritical water as a working fluid can extract up to 10 times more energy,” Quaise points out. The company has already raised about $63 million. They expect to have their equipment deployed in the field within two years.
Now they plan the deepest hole in the Earth, but that’s not all. They hope to take over coal-based power plants, and transform them into geothermal plants. These have the ability to convert steam into electricity.
Soon, a journey to the center of the Earth will begin, as Verne would never have imagined.