In recent years, excitement has been growing about the potential of geothermal energy, which draws heat from the Earth’s crust to generate electricity. I wrote a couple of introductory pieces on it for Vox a few years ago (one, two) and they remain some of the most popular things I ever published there.

To date, geothermal has largely been viewed as an always-on (“baseload”) resource, like nuclear power, that needs to maximize its running time (“capacity factor”) in order to maximize its revenue. Basically, it has been seen as a clean substitute for coal and nuclear power plants.

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However, new research from Princeton University's Zero Lab suggests that enhanced geothermal systems (EGS), which fracture underground rock to create their own reservoirs rather than relying on natural ones, can play a much more dynamic and valuable role — a role more like the one fast, flexible natural gas plants play today.

In a paper published in May, researchers show how EGS plants can store energy (for up to 100 hours or more!) and rapidly ramp their output up or down, allowing them to act as both storage and flexible “clean firm” generation in a decarbonized electricity system.

If an EGS plant can store large amounts of energy for long periods of time and crank up its output when it is most needed, its value exceeds previous estimates by as much as 60 percent. And if EGS plants are more valuable than previously recognized, a follow-up paper from the same team shows, it could end up playing a much larger role in a decarbonized energy system than previously envisioned.

I contacted one of the authors of both papers, PhD candidate Wilson Ricks, to discuss what the research found, what EGS plants can and can’t do, and the expanded role they might play in clean energy going forward.