The New York Times recently published an article featuring Eavor Technologies Inc. and their closed-loop geothermal technology. They refer to the concept as die eierlegende wollmilchsau, a German phrase meaning the egg-laying wool-milk pig. This mythical creature is said to meet all human needs for food, drink, and fiber simultaneously. Closed-loop geothermal is the energy world’s egg-laying wool-milk pig with its ability to be flexible, reliable, renewable, affordable, and dispatchable.
Geothermal energy has held the promise of having substantial contributions to the clean energy transition. Traditional geothermal’s challenge has been that it only works where there is a very specific confluence of temperature, subsurface water, and permeability—this makes it far from universal.
The next generation of geothermal technology, Advanced Geothermal Systems (AGS), could work anywhere with subsurface temperature gradients of 30 degrees Celsius or more and involves no fracking or pumping load. Closed-loop systems can also be the perfect complement to renewable energy, specifically solar energy. When the sun goes down, solar energy stops generating but paired with AGS, excess energy would be stored and available when a burst of power was needed.
“The impact of AGS on the cost of achieving net zero electrical grids could be dramatic. A detailed system study, commissioned by leading AGS proponent Eavor and conducted by Princeton-based engineering professor Dr. Jesse D. Jenkins and modellers DeSolve LLC found that, in the case of the United States Western Interconnection, an optimized system might meet between 20 percent and 40 percent of its demand using AGS, delivering savings of up to $20 billion per year over a system with no AGS.” – New York Times
Eavor has successfully demonstrated this technology is guaranteed to work. The only real question today is around cost. Projects selling heat or electricity should be profitable, and if AGS can take advantage of innovation and learning to reduce drilling costs, it should be able to deliver on the promise of geothermal anywhere.