Geothermal energy is poised for a big breakout

“The main problem facing renewable energy is that the biggest sources, wind and solar, are variable. Whereas fossil fuel power plants that run on coal and gas are “dispatchable” — they can be turned on and off on demand — wind and solar come and go with, well, the wind and sun.

Building an electricity system around wind and solar thus means filling in the gaps, finding sources, technologies, and practices that can jump in when wind and solar fall short (say, at night). And the electricity system needs to be extremely secure and robust, because decarbonizing means electrifying everything, moving transportation and heat over to electricity, which will substantially raise total electricity demand.

The big disputes in the clean energy world thus tend to be about how far wind, solar, and batteries can get on their own — 50 percent of total power demand? 80 percent? 100?) and what sources should be used to supplement them. (See this much-cited 2018 paper in the journal Joule on the need for “firm, low-carbon resources.”)

The answer currently favored by renewable energy advocates is more energy storage, but at least for now, storage remains far too expensive and limited to do the full job. The other top possibilities for “firming” electricity supply — nuclear power or fossil power with carbon capture and sequestration — have their own issues and passionate constituencies for and against.

Geothermal power, if it can be made to reliably and economically work in hotter, drier, and deeper rock, is a perfect complement to wind and solar. It is renewable and inexhaustible. It can run as baseload power around the clock, including at night, or “load follow” to complement renewables’ fluctuations. It is available almost everywhere in the world, a reliable source of domestic energy and jobs that, because it is largely underground, is resilient to most weather (and human) disasters. It can operate without pollution or greenhouse gases. The same source that makes the electricity can also be used to fuel district heating systems that decarbonize the building sector.

It checks all the boxes.”

“Tapping into it, though, turns out to be pretty tricky.”

A national US power grid would make electricity cheaper and cleaner

“The US does not actually have a national grid. Our grid is instead split into three regions — the western interconnection, the eastern interconnection, and, uh, Texas — that largely operate independently and exchange very little power.”

“this is a barrier preventing all sorts of efficiencies.”

“87 percent of the nation’s total wind energy potential and 56 percent of its utility-scale solar potential, but are only projected to account for 30 percent of the nation’s energy demand in 2050.”

“The way to balance this out — to make sure that every region is producing as much renewable energy as possible and that the energy is put to good use — is to connect these regions with high-voltage transmission lines. The more each region can import and export electricity, the more it can balance its own fluctuations in supply and demand with its neighbors’ and maximize the use of renewable energy.”

“Clack and his co-authors also found that weaving the regionally divided power system into a single national system would save consumers around $47.2 billion a year through increased efficiency and cheaper renewable energy.”

“The best way to build resiliency against these events, which are increasing in frequency due to climate change, is to connect the regions of the country into a single national grid, so that regions facing difficulty can draw power from neighbors who aren’t.”

“investment into a national grid would create thousands of construction and maintenance jobs.”