Extracting heat from the ground to produce clean energy could work on a commercial scale

Breakthrough at Utah’s unique underground laboratory “bodes well for 24/7 renewable energy.”

Scientists have spent years fracking outside Milford, sinking chemicals and water into the ground to break up the rock, using the same technique that has been controversial in the oil and gas industry.

In April, they tested whether the water would flow through the hot cracked granite and whether enough gallons would return to the surface, heated by the earth’s heat enough to produce steam power.

For eight hours they didn’t see anything happening.

Then a boiling wave rolled through their monitors, proving that clean energy from Earth could work on a commercial scale.

“This is a group that doesn’t give a lot of high-fives,” researcher John McLennan said with a laugh, “but it was a huge relief and sense of satisfaction for everyone.”

He explained that it showed that geothermal energy harvested in this way “is a viable form of energy. This bodes really well for renewable energy, which is available 24/7.”

The Utah Frontier Geothermal Energy Research Observatory, a U.S. Department of Energy-sponsored underground field laboratory in Beaver County, is the largest geothermal energy experiment in the country. The site announced the results of its April experiment on May 23.

Think of the volcanoes and geysers in Yellowstone National Park as examples of geothermal energy. Capturing heat inside the earth as steam can produce renewable energy.

Traditional geothermal power plants use underground reservoirs that have three characteristics: heat, water and permeability. The plants direct the water to one well, where the heat of the earth heats it as it flows through cracks in the hot rock toward the other well. They then pull the heated water back to the surface. Steam from the heated water can turn a turbine, which in turn turns on a generator to produce electricity.

It is rare to find underground tanks that have all three of these features. Utah FORGE intends to change this by creating artificial geothermal reservoirs.

“We are excited about these extraordinary achievements for FORGE and the promise this geothermal breakthrough holds for our clean energy future,” said Jeff Marootian, principal deputy assistant secretary in the Department of Energy’s Office of Energy Efficiency and Renewable Energy.

“The ability to harness more of the Earth’s natural heat through improved geothermal systems will expand access to affordable, safe and resilient clean energy for everyone,” he said.

This recent experiment builds on progress made last summer, when FORGE scientists managed to push water through deep fractures created by fracking. Although they managed to force water underground and watch it return to the surface, this experiment did not produce enough heated water to prove commercial viability.

McLennan said the FORGE facility in Utah is the best location for this type of geothermal energy harvesting due to its temperature, depth and low earthquake frequency. Researchers there don’t have to drill too deep to find hot enough rock to produce geothermal energy, and the area is, in McLennan’s words, “relatively seismically benign.”

Injecting high-pressure water into the ground to create cracks or widen existing ones can activate a fault zone and increase the risk of earthquakes. Utah FORGE reported that its latest experiment produced a seismic activity of 1.9 on the Richter scale; by comparison, the U.S. Geological Survey reports that most people experience earthquakes above magnitude 3.0.

All but 30% of the water injected into the ground during the April experiment – a total of almost 5 million gallons – returned through the production well. The non-potable water used in the experiment came from a well drilled on the site. In a commercial setting, this water would be injected back into the ground and pumped again to produce more energy.

The next step in obtaining clean energy from the ground will be another July experiment at FORGE. This test will last 30 days to assess the pressure at which researchers should inject water to circulate it for an extended period of time, and to determine the temperature of the water produced during that time frame.

The U.S. Department of Energy, in a 2024 report, stated that geothermal energy will reach full commercial scale by 2050. The United States produces more geothermal energy than anywhere else in the world. However, according to the U.S. Energy Information Administration, geothermal energy accounted for only 0.4% of the country’s total electricity production in 2022.