San Francisco-based startup Earthgrid is developing a plasma boring robot that can dig tunnels 100 times faster, and up to 98 percent cheaper than existing boring systems, a report from New Atlas reveals.
The company aims to employ its technology to re-wire energy, internet, and utility grids in the U.S.
Unlike conventional boring machines, which typically use massive cutting wheels to slowly excavate tunnels, Earthgrid’s robot blasts rocks with high temperatures to break and even vaporize them via a process called spallation.
Earthgrid is currently operating on pre-seed funding, and it is developing its “Rapid Burrowing Robot (RBR)”, a spallation boring robot with several 48,600 °F (27,000 °C) plasma torches mounted on large discs.
The RBR will light up those torches and rotate the discs to blast the rocky surface in its way. The torches on the discs are arranged in a Fibonacci spiral, meaning they widen out away from the center for full coverage. Debris is collected in small pushcarts.
Earthgrid has submitted a patent for its machine, which provided estimates for the energy required to power those torches. A version of the RBR using 72 plasma torches to drill a 1-meter (3.3-ft) bore, for example, would require roughly 40 megawatts of electricity on the low-power setting. For large tunnels, Earthgrid explains, large rigs would be attached to the back of the BRB, reaching power draws of around 1.38 gigawatts.
If it uses a high-speed configuration, Earthgrid says it can tunnel up to 1 kilometer (0.62 miles) per day.
“We are so much less expensive,” Earthgrid’s website reads, “due to far lower operating costs (no need to change out drill bits & cutter heads multiple times daily, much lower energy consumption, robotics = far fewer workers, no drilling mud and/or drilling chemicals to dispose of, easier spoils removal, sale of our spoils for road & concrete manufacturing, etc.)”
The company is now heading toward a seed funding round. It faces competition from another company, Petra, which is also developing a plasma boring robot.