Void Shaft Electricity

[Image: An engraving of mining, from Diderot’s Encyclopedia.]

A Scottish firm called Gravitricity wants to turn abandoned mine shafts into gravity-driven, underground electrical batteries. Power could be generated and stored, the Guardian reported back in late 2019, “by hoisting and dropping 12,000-ton weights—half the weight of the Statue of Liberty—down disused mine shafts.”

By timing these drops with regional energy demand, Gravitricity’s repurposed mines could act as “breakthrough underground energy-storage systems,” a company spokesperson explains in a video hosted on their site.

“Gravitricity said its system effectively stores energy by using electric winches to hoist the weights to the top of the shaft when there is plenty of renewable energy available, then dropping the weights hundreds of meters down vertical shafts to generate electricity when needed,” the Guardian continues.

[Image: From the Gravitricity website.]

In Subterranea: The Magazine for Subterranea Britannica, where I initially read about this plan, some of the proposal’s inherent design limitations are made clear. “What would be required for the Gravitricity scheme,” SubBrit suggests, “would be very deep, wide, and perhaps brick-lined shafts clear of ladderways, air ducts, cables and the like. On what sort of surface the weights might land, time and time again, is another consideration.”

Of course, this suggests that such shafts could also be deliberately designed and excavated as purpose-built battery-voids stretching down hundreds—thousands—of meters into the Earth, a not-impossible architectural undertaking. Repurposed domestic wells, using smaller weights, could also potentially work for single-home electrical generation, etc. etc.

So here’s to a new generation of proposals for how to perfect such a scheme, proposals that should be awarded bonus points if the resulting gigantic underground cylinders might also function as seismic invisibility cloaks (or “huge arrays of precisely drilled holes and trenches in the ground”).

Leave a Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.