Germany Taps Underground Heat With Giant Radiator System

In a clearing near Munich, drilling rigs are boring three miles into the Earth not for oil or gas, but to build what might be the future of clean heating.

The technology works like a giant underground radiator. Canadian company Eavor pumps water down deep wells equipped with long prongs that snake through hot rock, then brings the heated water back to the surface.

Unlike traditional geothermal energy that depends on finding natural underground hot water reservoirs, this "closed-loop" system can work almost anywhere. The company drills deep enough to reach hot rocks, circulates water through miles of contact with those rocks, and harvests the heat.

"If this technology is proven and commercially viable, it's a complete game-changer everywhere in the world," said Heymi Bahar, a senior analyst at the International Energy Agency.

The Geretsried plant already started feeding electricity into Germany's grid in December using its first completed loop. The project's sponsors now hope to pipe hot water to nearby towns for heating, replacing fossil fuel systems that many European municipalities still use.

The timing couldn't be better. Growing demand for electric power to feed data centers is boosting interest in geothermal energy as a steady, low-carbon alternative. North America "is on the precipice of a massive boost in capacity," according to Shruti Raghuram, a geothermal analyst at Rystad Energy.

The approach has major advantages over wind and solar. "Neither of those technologies can directly produce heat," said Chris Cheng, Eavor's comanaging director for Germany. Many European towns have district heating systems that could swap out their fossil fuel plants for geothermal heat relatively easily.

The Ripple Effect

The drilling expertise comes from oil and gas workers finding new purpose in clean energy. With fossil fuel exploration sluggish in Europe, geothermal projects offer drilling contractors and workers an alternative that uses their specialized skills for climate solutions instead of carbon emissions.

The approach also avoids fracking, which many countries oppose, making it more politically viable worldwide. Germany's strict regulations actually helped the project, Cheng noted. "There are many boxes to tick, but if you check them off, you know you're going to get your project approved."

The road hasn't been easy. Drilling such long, complex wells and connecting them underground took two years for just the first loop. The full project will cost an estimated $354 million, though it's already received a $108 million grant from the European Union.

Questions remain about whether costs can drop enough for widespread adoption. But if they can, this technology could turn the Earth itself into a clean heating system accessible to communities worldwide, no hot springs required.