California's XGS Energy has found a way to access untapped geothermal heat under the Earth's crust using a "special mud," as TechCrunch detailed.
It's part of the company's goal to expand the sustainable energy source that, for various reasons, hasn't accelerated like wind and solar. Geothermal produces less than half a percent of U.S. electricity, per government statistics.
"XGS has brought together the right team with the right technology to unleash the potential of geothermal energy," XGS Chairman of the Board Craig Barrett said in a press release from early this year, announcing a $9.7 million financing round the company landed.
Geothermal tech generally involves drilling into the Earth to access heat. Shallower depths provide a stable temperature to warm and cool homes. Other methods involve drilling far deeper (up to 12 miles or more in at least one case) to leverage extreme heat from below the surface.
XGS targets depths that provide temperatures of at least 482 degrees Fahrenheit. That ultimately heats water that is returned to the surface.
Geothermal systems frequently pump water underground and then pull it to the surface to provide electricity, often by powering a turbine. But over time, the heat-holding underground cracks can close, or take in too much water, causing the well to fail, per TechCrunch.
"The history of geothermal has been this notion of degradation," XGS CEO Josh Prueher told the publication. "This is happening all over the world."
The company's patented process uses what TechCrunch describes — based on discussion with Prueher — as a "specialized mud" that could remedy the problem. Better yet, the process can salvage old wells or work for new drill sites.
Proprietary thermally conductive material is injected around the wellbore, filling the fissures, and pulling heat to the shaft, as XGS describes it. The "mud" is made in part from minerals that are good at conducting heat.
A special well casing lines each hole, collecting the warmth, which heats water that's running through the system as part of a closed-loop setup. This prevents lost water, degradation, and other problems that have plagued the sector.
A big advantage to the process is that it reuses the same water repeatedly, making the technique viable in dry places. The company notes that other operations can use millions of gallons of water a day.
The result for XGS is a less-costly method that includes a more than 30-year warranty.
"We know within 30 days where we're going to be in 30 years" regarding power production, Prueher said in the TechCrunch report.
Geothermal has the potential to provide nearly unlimited energy without harmful air pollution. The U.S. Energy Information Administration reports that in 2022, electricity production from "all energy sources" made 1.82 billion tons of carbon dioxide pollution.
XGS could help to open up geothermal as part of an energy transformation that eliminates the exhaust. Less air pollution has a range of benefits, even limiting the risk of extreme weather that NASA links to planet-warming gases.
TechCrunch reports that XGS recently landed another $20 million to help build a commercial-scale prototype this summer in California as part of its next phase, all backed by top experts.
"Our team is composed of the best and brightest minds with hundreds of years of cumulative experience in materials science," XGS boasts on its website.
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