Sonoma County geothermal energy leader says underground heat is key to help reverse global warming

Editor’s Note: The Press Democrat is publishing a series of stories about Sonoma County innovators who are tackling global warming. We invite readers to propose stories of those involved locally in climate change. Share your ideas by contacting our editor, rick.green@pressdemocrat.com.

Thanks to The Geysers in the northeast corner of Sonoma County, which is the largest, cleanest, developed geothermal field in the world, almost 1 million people in five North Bay counties can get electricity that is clean, renewable and available 24 hours a day.

Could it be possible for all areas of the world to get electricity powered by clean geothermal energy and help reverse global warming?

That’s what some experts in Sonoma County are looking at today. These engineers and scientists, drawn to Sonoma County decades ago by The Geysers, are key players in an international revolution shaking the geothermal industry.

They call it “Geothermal Anywhere.”

In this scenario, the industry would harness the heat that is underground everywhere to create energy, even when there’s no existing liquid or steam underground to bring it to the surface. Experiments are underway to solve technological hurdles and bring down costs to make this commercially feasible.

“If we can do it, I think that’s the future,” said Louis Capuano, president and CEO of Capuano Engineering in Santa Rosa, which drills geothermal wells worldwide.

“The potential resource is vast and environmentally friendly, we just need to find ways to produce it,” said geologist Gene Suemnicht, CEO of EGS Consulting. The Santa Rosa company’s job is to find the best places for people like Capuano to drill.

Industry experts believe that some experimental wells could be ready next year, while cautioning that widespread use is still some years away.

Two years ago, the leading geothermal trade association in the U.S. rebranded itself as Geothermal Rising. It was a move to reflect the new direction of the industry, which, in 2021 provided only 0.4% of U.S. electricity generation, according to federal data, but aims to have a much larger impact.

“We want to show the people of the world how we can use the Earth to save the Earth,” said Executive Director Will Pettitt.

The Santa Rosa companies Capuano Engineering and EGS Consulting are deeply influential in their field and its new direction, according to industry leaders who work with them.

Capuano is “an icon in geothermal energy who has probably drilled more geothermal wells than anybody in the world,” said Walt Kolbe, chief operation officer of Geothermic Solution in Palo Alto.

At EGS, founder and president Paul Brophy and CEO Suemnicht “are very very well respected in the industry,” Capuano said. “When I have to bring in a geologic firm, they’re the ones I always call.”

The three men have worked in the industry almost five decades and served multiple times in leadership roles in local, national and international geothermal associations.

All have worked on projects throughout the world including Asia, Africa, Europe, the Middle East, North, Central and South America and the Caribbean.

It’s hard to exaggerate the complexities of their work.

Geologists like EGS have to interpret the constantly changing conditions through miles of rock formations and project what layers might be permeable and how to reach potentially productive regions. They map, evaluate, monitor every step of the drilling and help manage the resource as it is being produced.

“Our job is to say, ‘Drill here,’” Suemnicht said.

Drillers like Capuano use the geologists’ information to develop a safe and efficient drilling plan, choose materials, determine hole size at various depths, retain subcontractors who do the drilling, anticipate when and how to maneuver underground hazards and changing conditions, rapidly adjust and take the drill to the exact spot the geologists recommended.

“He’s a juggler with a lot of balls in the air,” Suemnicht said.

A typical well at the Geysers might be 8,000 feet deep, take 60 days to drill and cost $5 million to $6 million, with each Santa Rosa company getting roughly 2% of that cost, the men said.

Busy every day with traditional geothermal projects around the globe, they also teach, write, mentor and work to advance Geothermal Anywhere.

Today, that movement is a collection of experiments being conducted by private entrepreneurs, the U.S. Department of Energy and others.

One example called Direct Use, which has been used in some areas for decades but is attracting more interest in the era of global warming, involves digging trenches or relatively shallow wells to capture moderate temperatures for heating water and interior spaces.

For example, Capuano just completed a well for Cornell University in Ithaca, New York, and EGS just finished work for Golden Haven Hot Springs Spa & Resort in Calistoga.

Both companies are mainly focused on drilling much deeper into the earth, to produce energy that can run turbines and generators to create electricity.

One example is closed-loop technology, using newly drilled or existing wells to circulate liquid through pipes down through intense zones of heat, back to the surface to create electricity and down again to repeat.

Several companies are trying variations of this technology, for example by using different liquids, materials or pipe system designs, Capuano said.

An example is Geothermic Solution in Palo Alto, where Capuano and EGS are technical advisers. This approach inserts a pipe-within-a-pipe roughly 2 to 4 miles into rock that is 572 to 650 degrees Fahrenheit, to cycle liquid down and up.

Chief operating officer Kolbe said in a telephone interview he expects to finish design, procurements and other preparations to begin drilling next August at an undisclosed location.

“We expect full installation along with enough data to say where things are within six months after that,” Kolbe said.

In another example, Benjamin Barker, a geothermal engineer and consultant who lives in Windsor and New Hampshire, is a consultant to the U.S. Department of Energy’s FORGE project outside of Milford, Utah.

It will drill two wells and enlarge fractures in the hot rock between them. Water will then flow down one well and through the hot rock to the other well to return to the surface.

The first well was drilled in 2020 to a depth of 1.5 miles and 442 degrees Fahrenheit and water has been sent down to look for cracks that can be enlarged. Drilling on the second well could begin next spring and they could spend one to two years running test loops, Barker said.

Sonoma Clean Power, an agency that provides electricity for 87% of potential customers in Sonoma and Mendocino counties, is also considering closed-loop technology for its GeoZone project, which seeks to encourage more local geothermal development in the region.

Mary Fricker is a retired Press Democrat business reporter. She lives near Graton. Reach her at mfricker@sonic.net.