USA lives race for geothermal energy – 02/09/2023 – Environment

In a sagebrush valley filled with wind turbines and solar panels in western Utah, Tim Latimer was looking at a very different device that he thought could be just as powerful in combating climate change—perhaps even more so.

It was a drilling rig, transplanted from the North Dakota oil fields. But the smooth hum of the platform wasn’t looking for fossil fuels. I was drilling for heat.

Latimer’s company, Fervo Energy, is part of an ambitious effort to release vast amounts of geothermal energy from Earth’s hot interior, a renewable energy source that could help replace fossil fuels that dangerously heat the planet.

“There’s a virtually unlimited resource down there, if we can access it,” Latimer said. “Geothermal doesn’t take up much land, it doesn’t produce emissions, it can complement wind and solar power. Everyone who sees this is obsessed.”

Traditional geothermal plants, which have been around for decades, work by tapping into natural reservoirs of hot water underground to power turbines that can generate electricity 24 hours a day. However, few places have the right conditions, which is why geothermal energy only produces 0.4% of US electricity.

But there are hot, dry rocks beneath the surface of the entire planet. And by using advanced drilling techniques developed by the oil and gas industry, some experts think it’s possible to tap into this larger store of heat and create geothermal energy almost anywhere.

The potential is huge: the Department of Energy reckons there’s enough energy in these rocks to power the entire country five times over, and has launched a major initiative to develop technologies to capture the heat. Dozens of geothermal companies submitted ideas.

Fervo is using “fracking” techniques — similar to those used for oil and gas — to break open hot, dry rocks and inject water into fractures, creating artificial geothermal reservoirs.

Eavor, a Canadian startup, is building large underground radiators using pioneering drilling methods in the oil sands of Alberta (central Canada).

Others dream of using plasma or wave energy to drill even deeper and reach “superheated” temperatures that could cleanly power thousands of coal-fired power plants, replacing coal with steam.

Still, obstacles to geothermal expansion arise. Investors are wary of the costs and risks of new geothermal projects. Some worry about water usage or earthquakes caused by drilling. Permission is difficult, and geothermal receives less federal support than other technologies.

Still, the growing interest in geothermal energy is driven by the fact that the United States has become extraordinarily good at drilling since the 2000s.

Innovations such as horizontal drilling and magnetic sensing have driven oil and gas production to record levels, much to the dismay of environmentalists. But these innovations can be adapted for geothermal energy, where drilling can be half the cost of projects.

“Everybody knows about the falling cost of wind and solar power,” said Cindy Taff, who worked at Shell for 36 years before joining geothermal startup Sage Geosystems in Houston (Texas). “But we’ve also seen sharp drops in the cost of drilling for oil and gas during the shale revolution. If we can translate that into geothermal energy, the growth could be huge.”

‘Fracking’ for clean energy

Near the town of Milford, Utah, sits the Blundell geothermal plant, surrounded by boiling mud pits, hissing steam vents and the skeletal ruins of a hot spring resort. Built in 1984, the 38 megawatt plant produces enough electricity for about 31,000 homes.

The Blundell plant relies on ancient volcanism and geological quirks: Just below the surface are hot, naturally porous rocks that allow groundwater to seep in and heat up enough to create steam, which generates electricity.

But such conditions are rare. In much of the region, the hot rock underground is hard granite, and water does not flow easily.

Five kilometers to the east, two teams are trying to explore that hot granite. One is Utah Forge, a $220 million research effort funded by the Department of Energy. The other is from Fervo, a Houston-based startup.

Both use similar methods: First, they drill two shafts in the shape of a giant “L”, extending thousands of meters into the hot granite, before curving and extending thousands of meters horizontally.

They then use “fracking,” which involves controlled explosives and high-pressure fluids, to create a series of fissures between the two wells. Finally, they inject water into one well and wait for it to migrate through the cracks, heat up to over 150°C and exit out the other well.

This is called enhanced geothermal, which has been grappling with engineering difficulties since the 1970s.

But in July, Forge announced that it had successfully sent water between two wells. Two weeks later, Fervo announced its own breakthrough: A 30-day test in Nevada found that the process could produce enough heat to generate electricity.

Fervo is now drilling wells for its first commercial 400-megawatt power plant in Utah near the Forge facility.

“These are important achievements, in a shorter period of time than we expected,” said Lauren Boyd, head of the Department of Energy’s Office of Geothermal Technologies, who estimates that geothermal energy could provide 12% of US electricity by 2050 if the technology is enhanced.

Latimer looked less surprised. Before founding Fervo in 2017, he worked as a drilling engineer at BHP, an oil and gas company. There he became convinced that previous attempts to improve geothermal energy had failed because they did not take advantage of oil and gas innovations such as horizontal drilling or fiber optic sensors.

Fervo didn’t invent many of the tools it uses. In Utah, drilling is conducted by Helmerich & Payne, a major oil and gas contractor that has developed a high-tech rig with software and sensors that allow operators to precisely direct the bits underground. Sixty percent of Fervo’s employees came from the oil and gas industry.

“If we had to come up with these things ourselves, it would take years or decades,” Latimer said. “Our big takeaway was that people in the geothermal space just didn’t talk enough to people in the oil and gas industry.”

The hard part now is making improved geothermal energy accessible. The Department of Energy wants costs down to $45 per megawatt-hour for widespread deployment. Fervo’s costs are “much higher,” Latimer said, although he believes repeated drilling could reduce them.

Forge search can help. Deeper and hotter drilling can make projects more cost-effective, as more heat means more energy. But existing oil and gas equipment isn’t designed for temperatures above 180°C, so Forge is testing new tools in hotter rocks.

“Nobody else is willing to take the risks that we can,” said Joseph Moore, a geologist at the University of Utah who leads Forge.

Improved geothermal faces other challenges, warned Moore. The underground geology is complex, and it’s difficult to create fractures that hold in heat and don’t lose too much water over time.

The drillers are not expected to trigger earthquakes, a problem that has plagued geothermal projects in South Korea and Switzerland. Forge closely monitors its Utah facility for seismic activity, and has found nothing of concern.

Permission is difficult. While improved geothermal energy could, in theory, work anywhere, the best resources are on federal land, where regulatory reviews take years, and it’s often easier to get permission to drill for oil and gas because of exemptions obtained by companies. of fossil fuels.

Still, interest is growing. California is struggling with electricity shortages and recently had to extend the lives of three old, polluting gas-fired power plants.

Regulators have ordered utilities to add 1,000 megawatts of electricity from clean sources that can run at any time to stem fluctuations in wind and solar power supplies. One electricity supplier, the Clean Power Alliance, has agreed to purchase 33 megawatts of Fervo’s plant in Utah.

“If we can find it, we’ll have a big appetite for geothermal energy,” said Ted Bardacke, CEO of the Clean Power Alliance. “We’re adding more solar energy every year for daytime use, and we have a huge backlog of batteries to transfer the energy into the night. But what do we do at night? That’s where geothermal can really help.”

_{Translated by Luiz Roberto M. Gonçalves}