Geothermal Could Replace 42% of EU Fossil Fuel Power

The ground beneath our feet might be the clean energy breakthrough Europe has been waiting for.

A new report from energy think tank Ember reveals that geothermal energy could replace 42 percent of the European Union's electricity from coal and natural gas at the same cost. New drilling technologies borrowed from the oil and gas industry are making this possible by reaching deeper underground and creating pathways for water to heat up in previously unusable locations.

Geothermal works by pumping water through hot rock underground, where it heats up and returns to the surface to power turbines. Unlike solar and wind, which depend on weather conditions, the Earth's core provides constant heat day and night, season after season.

"We can't really say that all of it will be utilized, but there is enough of it to get policymakers and investors more interested, even in Europe and even outside of traditional hot spots," said Tatiana Mindeková, a policy advisor at Ember who led the report.

The game changer is enhanced geothermal technology that drills several miles deep and fractures rock to create space for water to flow and heat. This opens vast new regions beyond volcanic hot spots where geothermal traditionally worked. Engineers are essentially creating their own underground heat exchangers anywhere they drill.

The technology faces real challenges. Drilling miles deep is expensive and technically difficult, and costs vary depending on how quickly temperature rises underground in different locations. Some rock types also add minerals to the water that can damage equipment.

But like solar panels and wind turbines before it, costs are dropping as the technology matures. "To the extent that we see more deployment of advanced geothermal in Europe, we're going to see that bring down the cost of applying the innovation in lots of other places in the world," said David Victor, co-director of the Deep Decarbonization Initiative at UC San Diego.

The Ripple Effect

Geothermal's benefits extend far beyond electricity generation. In the EU, households use more than three quarters of their energy just heating homes and water, and shallower geothermal systems can meet that need directly.

Networked geothermal drills just 600 to 700 feet down and circulates water at the ground's constant temperature. Heat pumps in individual homes extract warmth in winter and deposit heat underground in summer, creating a seasonal cycle that stores energy for year-round comfort.

The Earth can even act as a giant battery. When solar panels and wind turbines produce excess electricity, facilities can heat water and pump it underground for storage. Later, when renewables aren't generating power, that hot water returns to the surface to fill the gap.

Wayne Bezner Kerr, who manages Cornell University's Earth Source Heat program, sees the potential despite the technical challenges. The irony isn't lost on researchers that oil and gas drilling techniques are now helping unlock clean energy that could replace fossil fuels.

The future of clean energy might not be in the sky or on rooftops, but beneath our feet all along.