Few people up Earth has moved closer to the center than Buzz Speyrer, a drilling engineer with a long career in oil and gas. It’s about 1,800 miles to the core, smoldering from celestial impacts that date back billions of years and are fueled by friction and radioactivity to this day. That heat seeping up turns the rock above into a viscous liquid and beyond into a jelly-like state that geologists call plastic. It’s only within about 100 miles of the surface that rock becomes familiar and hard and drillable.
Right now, Speyrer’s gear is about 8,000 feet below us, or about 2 percent of the way through that layer, where the heat is already so great that every extra foot, every extra inch is a hard-fought victory. Down there, any liquid you pumped into it would, as Speyrer puts it, get hot enough to fry a turkey. “Imagine splashing,” he says. At that temperature, about 450 degrees Fahrenheit (228 degrees Celsius), his gear could start to have problems. Electronics fail. Warping bearings. Hundreds of thousands of dollars worth of equipment can end up in a borehole, and if it breaks down there, make sure it doesn’t get stuck. In that case, your best bet is to just plug that hole, which probably cost millions to drill, add up your losses, and move on.
Even if things are going well down there, it’s hard to know from here on the Earth’s surface. “It’s extremely frustrating,” says Joseph Moore, a geologist at the University of Utah, as he watches the hesitant movements of a 50-foot platform through the window of a trailer. It’s a cool day in 2022, in a remote western Utah county called Beaver, with breezes blowing from the Mineral Mountains to pig farms and wind turbines at the valley floor. The platform is much like any oil and gas installation in the American West. But there are no hydrocarbons in the granite below us, only heat.
Since 2018, Moore has led a $220 million bet by the U.S. Department of Energy (DOE) called FORGE, or the Frontier Observatory for Research in Geothermal Energy, that this heat could be harnessed to produce electricity in most parts of the world. world. Geothermal energy is a rare resource today, tapped only in places where the crust has cracked a bit and heat mixes with groundwater, creating hot springs or geysers that can power electricity-generating turbines. But such watery hot spots are rare. Iceland, which straddles two diverging tectonic plates, hits a geological jackpot, producing about a quarter of its electricity that way; in Kenya, volcanism in the Great Rift Valley helps push that figure to more than 40 percent. In the US it is only 0.4 percent, almost all from California and Nevada.
Still, there’s hot rock everywhere if you drill deep enough. Moore’s project seeks to create an “enhanced” geothermal system, or EGS, by reaching hot, dense rock like granite, breaking it open to form a reservoir and then pumping in water to absorb heat. The water is then sucked up through a second well, which is a few hundred degrees hotter than before: an artificial hot spring that can power steam turbines. That design may sound straightforward, directing water from point A to point B, but despite half a century of work, the complexities of engineering and geology have so far failed to make EGS work on a practical scale.
Moore is trying to show that it can be done. And in the process, he may be able to get more entrepreneurs and investors who are just as excited about geothermal energy as he is. Renewable electricity generation, whether solar or wind or hot ground, typically provides stable but unremarkable returns once power starts flowing. That’s fine if your initial cost is cheap – a requirement that wind turbines and solar panels now generally meet. Geothermal just happens to require a risky multi-million dollar drilling project to get going. While clean, reliable energy sourced from the Earth’s core can supplement the on-again, off-again sap of wind and solar, there are safer bets underground for those with the expertise and funding to drill: It can It takes 15 years for a geothermal well to pay for itself; a natural gas installation does it in half.
No surprise, then, that there are 2 million active oil and gas wells worldwide, but only 15,000 for geothermal energy, according to Norwegian energy consultancy Rystad Energy. Almost all are hydrothermal, relying on those natural sources of hot water. Only a few are EGS. A trio of working factories in eastern France produce only a trickle of power, having drilled into relatively cool rock. Then there are hotter experiments, like here in Utah and across the border in Nevada where a Houston startup called Fervo is working on connecting two of its own wells, a project that aims to provide clean power to a Google data center .
Moore believes FORGE can make EGS more attractive by showing that it’s possible to make hotter. Every extra degree should mean more energy zapped into the grid and more profit. But drilling hot and hard granite, rather than cooler and softer shale that gas frackers like Speyrer typically split apart, is not trivial. Nor is drilling the wide wells required to move large volumes of water for a geothermal power station. So a chicken-and-egg problem: The geothermal industry needs tools and techniques adapted to oil and gas – and in some cases brand new ones – but because no one knows if EGS will work, they don’t exist yet. That’s where FORGE comes in, playing a role Moore describes as “reducing risk” of the tools and methods. “No one is going to spend that money unless I spend that money,” he says.
