why we need to talk more about geothermal energy
Usually, when we talk about renewable energy, we talk about solar, wind, and hydro, or dream about the potential of fusion. Then the contrarians, often with lucrative contracts paid by fossil fuel lobbies who don’t care if they turn the planet into a toxic waste dump, as long as the dollars keep flowing into their bank accounts, show up to tell us all their shortcomings. The sun doesn’t always shine, the wind doesn’t always blow, rivers can’t be everywhere, and we’re still just trying to make fusion workable. Meanwhile, seldom does anyone mention one of the best renewable sources we could hope to harness in the near future: geothermal energy.
Unlike the sun and wind, the heat from the breakdown of radioactive elements in our planet’s crust and the aftereffects of Earth’s formation, changes only slightly and over billions of years. All we need to do is drill deep enough, shoot a stream of water down into the well, then let superheated steam crank generators to create enough electricity to power entire neighborhoods. Best of all, we could do that pretty much anywhere, all day, every day until the Sun turns into a red giant and engulfs the long after life on the surface becomes impossible. As long as we protect them from quakes, our geothermal wells could deliver a steady supply of clean energy for eons.
So, if geothermal is such a terrific energy source with all the upsides of wind and solar but none of their downsides, why aren’t we using it in every major city? Well, mostly because the problem with making geothermal reliable and ubiquitous requires digging holes many miles into the Earth, further than even the deepest boreholes in existence. Right now, the record holder is the 12.3 kilometer deep and 23 centimeter wide Kola Superdeep Borehole in Russia. We’d need be able to reach deeper than 15 kilometers and make the boreholes at least a meter wide, which is very, very difficult and requires extremely complex and expensive equipment.
how to tame the planet for its clean energy
Enter Quaise Energy and their plan to do just that with an electron laser, burning as deep as 20 kilometers into the crust, where heat should be plentiful no matter where you’re setting up your power plant. To prove that it can be done, it raised $64 million and started scouting the locations for its first test boreholes targeting rock a kilometer under the surface. What are the odds it will succeed? It’s hard to tell since the technology is wildly experimental and while it’s plausible, it has yet to be tried outside the lab. Likewise, the cash it currently raised still won’t create a functioning geothermal plant, just fill out staff and build the first functional laser to be eventually scaled up for real world use.
But whether this startup succeeds or not — and hopefully it will — is not as important as the conversations it can start. Just consider that in the now terribly distant year of 2017, NASA drafted a proposal for disarming supervolcanoes that could cause apocalyptic destruction, while generating terawatts of clean power that could retail for as low as $0.10 per kilowatt hour for the next 100,000 years for just $3.5 billion. How would that work? By pumping both water and cooled steam through 350 °C to 550 °C rock, then letting the superheated steam crank generators on its way up, just like Quaise is planning to do in less exotic locations, and without slowly defanging potentially civilization-ending magma chambers.
Supervolcanoes are essentially just giant magma chambers formed by hot spots of magma under the planet’s crust. Over hundreds of thousands of years, they boil and churn, like in a pressure cooker, until enough superheated rock is fluid enough to start ratcheting up the internal stress past the breaking point as it convects. The rock over the chamber begins to unzip, which triggers ever more massive eruptions venting pyroclastic flows and giant ash clouds for up to a week, destroying ecosystems across an entire continent and plunging the planet into a volcanic winter lasting up to a decade. But as they churn and boil, they leak enough energy to power a megacity, which is where our technology comes in.
why we desperately need more geothermal efforts
If we were to take away enough heat with massive geothermal plants that shoot water under these giant magma chamber, the rock would eventually be too cool to trigger super-eruptions, even while it remained more than hot enough to keep generating power. If after thousands of years of siphoning off heat from the magma chamber increases the systems’ heat transfer by a third, there simply won’t be enough energy for them to erupt. Even more exciting, building geothermal plants near all 20 currently known supervolcanoes could provide us with more than a quarter of all the energy we’ll need by the 2050s. Add that to wind, solar, tidal, and yes, a new generation of nuclear plants, and we significantly help the environment going forward.
We dedicate so much attention to solar and wind, and spend so much time talking about how to store the energy they generate to use on cloudy and calm days while we pine for a fusion reactor, but we hardly ever mention the need to radically advance geothermal energy. While we spend $6 to $9 billion on power plants that use toxic and polluting fossil fuels, we could be spending a lot less to drill into the Earth for a steady, constant power supply for quite literally eons without the radioactive soot and ash shaving years off the lives of billions, and belching gigatons of toxic gases heating the planet even faster than the Permian Extinction, which was also known as The Great Dying.
Even better, we would be setting ourselves for long term success in three ways. First, we would be radically expanding the renewable energy supply with a source that’s always on and easy to dial up and down according to our energy needs. Secondly, we would be preventing pollution that is literally destroying our own habitats, not to mention that of countless other species. And finally, we would be slowly but surely preventing an entire class of devastating natural disasters that will kill tens of millions within weeks. Geothermal won’t be an ultimate solution for all our energy woes, but it has to be a critical part of our power generation mix and have a much more prominent part of the conversation. We simply have too much to gain from it.