“New experiments in the deserts of Utah and Nevada show how advances in fracking—technology developed by the oil industry—can be repurposed to tap clean geothermal energy anywhere on Earth,” reports Wired. It may soon become possible to drill deep into the Earth to get lots of geothermal energy. That would reduce the need to rely on fossil fuels, wind, and solar power (which would be good, because fossil fuels lead to global warming, wind energy kills many birds, and solar farms generate lots of toxic waste. A Google-owned solar farm incinerates a thousand birds every year).
Wired tells the story of Buzz Speyrer, a drilling engineer with a long career in oil and gas, who is drilling deep into the Earth in Utah — so far, about two miles deep. He chose an area where temperatures reach 450 degrees less than two miles below the surface:
Since 2018, Moore has led a $220 million bet by the US Department of Energy (DOE), called FORGE, or the Frontier Observatory for Research in Geothermal Energy, that this heat can be harnessed to produce electricity in most parts of the world. Geothermal energy is today a rare resource, tapped only in places where the crust has cracked a little and heat mingles with groundwater, producing hot springs or geysers that can power electricity-generating turbines. But such watery hot spots are rare. Iceland, straddling two diverging tectonic plates, hits a geological jackpot and produces 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’s just 0.4 percent, almost all of it coming from California and Nevada.
Yet there’s hot rock everywhere, if you drill deep enough. Moore’s project is trying to create an “enhanced” geothermal system, or EGS, by reaching hot, dense rock like granite, cracking it open to form a reservoir, and then pumping in water to soak up heat. The water is then drawn up through a second well, emerging a few hundred degrees hotter than it was before: an artificial hot spring that can drive steam turbines. That design can sound straightforward, plumbing water from point A to point B, but despite a half-century of work, the complexities of engineering and geology have meant no one has managed to make EGS work at practical scale—yet.
Moore is trying to demonstrate it can be done. And in the process, maybe he can get more entrepreneurs and investors as hyped about geothermal as he is. Renewable electricity generation, whether from sun or wind or hot ground, typically offers steady but unremarkable returns once the power starts flowing. That’s fine if your upfront costs are cheap—a requirement wind turbines and solar panels now generally meet. Geothermal happens to require a risky multimillion-dollar drilling project to get started. While clean, dependable power derived from the Earth’s core can complement the on-again, off-again juice from wind and solar, there are safer underground bets for those with the expertise and financing to drill: A geothermal well might take 15 years to pay for itself; a natural gas rig does it in two.
No surprise, then, that there are 2 million active oil and gas wells worldwide, but only 15,000 for geothermal…Moore believes FORGE can make EGS more attractive by showing it’s possible to go 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, isn’t trivial. Nor is drilling the wide wells required to move large volumes of water for a geothermal plant. Thus, a chicken-and-egg problem: The geothermal industry needs tools and techniques adapted from oil and gas—and in some cases, entirely new ones—but because nobody knows whether EGS will work, they don’t exist yet. Which is where FORGE comes in, playing a role Moore describes as “de-risking” the tools and methods. “Nobody is going to spend that money unless I spend that money,” he says.
In Beaver County, his team is testing a bridge plug—a cap, essentially—that will seal off a section of pipe so that water can be forced into surrounding rock with enough force to crack granite. It’s late morning and a dozen water tankers are parked in imposing formation next to the rig. Around lunchtime, they’ll test whether the plug can hold the pressure, and before dinner should fire “the guns”—small explosive charges—to perforate the pipe. Then they’ll push in the water to split the rock in time for a midnight snack—“if everything goes smoothly,” Moore says. In other words, a pretty standard frack, the technique that has flooded the US with a bounty of natural gas over the past 15 years.
More at this link.
