EarthGrid™ was featured in a WIRED Magazine article on underground excavation.

Tunneling experts who spoke to WIRED agree that the industry is crying out for technological solutions to lower costs and heighten efficiency — it can take years to design and build a Tunnel Boring Machine (TBM) and then actually dig a tunnel with it, for example. A suite of new companies promising to shake things up is emerging…

Troy Helming, Founder and CEO of San Francisco-based startup EarthGrid, emphasizes the need to put power lines underground — this is what his company aims to do. The vast majority of transmission cables are above ground in the United States and Canada, he notes, leaving them exposed to hurricanes and other storms as well as, increasingly, wildfires.

“Our plan is to put a supergrid across North America,” he says, proffering a map with colored lines showing said grid stretching all the way from the eastern seaboard to the Pacific Ocean, and future offshore wind farms in the west. It’s a plan that could help link up the fragmented US grid — and potentially one day even extend as far as Europe, to tap the huge offshore wind potential there. “It’s crazy and audacious, and we know that,” says Helming.

One hurdle is the extremely tough rock, such as granite and quartzite, that makes traditional excavation in some of these places difficult or impossible. Helming is betting on plasma torch technology that heats rock to about 6,000 degrees Celsius, blasting it to smithereens, as the solution. He suggests that this could allow for the creation of tunnels in hard rock 100 times faster than with current technology. EarthGrid is developing a prototype robot wielding five plasma torches, which Helming says should be ready for testing in March 2023. The firm also aims to complete its first, small-scale commercial project by the end of this year.

Helming notes that, in EarthGrid’s case, the tunnels will not be circular in shape but rather a traditional horseshoe — imagine a square with an arch on top, instead of a flat ceiling. This, he argues, makes it easier to install cable racks or, in larger transportation tunnels, a road surface on the flat base of the tunnel.