Meet 5 startups working to harness the Earth’s heat to save the planet
There are a few sources of power that are “free” here on Earth, namely wind, solar, hydro, and geothermal. Humans have been harnessing hydro and wind for millennia and are getting better at harnessing the sun’s power. However, geothermal is still a relatively new technology that allows us to exploit the heat generated deep within our planet.
The most commercial-scale geothermal installations take place in geologic hotspots such as Iceland and Northern California. Many homeowners have drilled small wells or buried loops to heat and cool their yards. To unlock the full potential of geothermal energy around the world, and make it profitable, we will need new ways to drill down and draw the heat up.
As the world struggles through an energy transition many energy experts talk at length about dispatchable baseload power. It’s a lot to take in. “Dispatchable” refers to the ability of grid operators to request power from a plant at any time. Baseload is power that is always available, regardless of the weather. Baseload power is not available for renewables like wind and solar. It’s a whole different story if they are paired with batteries to store power for when the sun isn’t shining or the wind is calm. The renewables-plus-batteries combo is happening with increasing frequency, but batteries remain expensive, and why not have more options than just that?
We need new methods to drill deep and draw the heat up in order to unlock geothermal’s full potential.
Geothermal has been promoted as a carbon-free source for dispatchable baseload power. This is why energy experts are warming to it. A working fluid, often water, is injected underground and heated before being pulled up to run through a heat exchanger, or drive a turbine.
The source of heat is almost limitless. The Earth continuously generates about 44 terawatts worth of heat, about half of which comes from naturally occurring radioactivity. That’s about 385,000 terawatt-hours of energy released every year, far more than global energy use, which in 2019 was just shy of 23,000 terawatt-hours. We’d have plenty of energy if we could tap into even a fraction of the Earth’s heat.
Geothermal is a promising technology that coincides with the decline of the fossil fuel sector, which is causing many engineers to rethink their careers. Many of the drilling techniques used in the oil and gas industry can be applied to geothermal.
There’s a lot of startups trying to make geothermal a mainstream power source. Here are five I have been following.
If there was an award for the sexiest geothermal technology, Quaise Energy would probably be the winner.
I’m a journalist who specializes in investigative reporting and writing. I have written for the New York Times and other publications.