Wednesday, February 19, 2020

Science & Technology: Penetrating Rock at Faster Speeds, to Greater Depths, and at a Lower Cost than Conventional Drills

AltaRock Energy Melts Rock With Millimeter Waves for Geothermal Wells (IEEE Spectrum)

Paul Woskov of MIT holds water-cooling lines leading to a test chamber, and a sample of rock with a hole made by a beam from a gyrotron. Photo: Paul Rivenberg/MIT

The Seattle-based company received an ARPA-E grant to test and scale its technology

A vast supply of heat lies beneath our feet. Yet today’s drilling methods can barely push through dense rocks and high-pressure conditions to reach it. A new generation of “enhanced” drilling systems aims to obliterate those barriers and unlock unprecedented supplies of geothermal energy.

AltaRock Energy is leading an effort to melt and vaporize rocks with millimeter waves. Instead of grinding away with mechanical drills, scientists use a gyrotron—a specialized high-frequency microwave-beam generator—to open holes in slabs of hard rock. The goal is to penetrate rock at faster speeds, to greater depths, and at a lower cost than conventional drills do.

The Seattle-based company recently received a US $3.9 million grant from the U.S. Department of Energy’s Advanced Research Projects Agency–Energy (ARPA-E). The three-year initiative will enable scientists to demonstrate the technology at increasingly larger scales, from burning through hand-size samples to room-size slabs. Project partners say they hope to start drilling in real-world test sites before the grant period ends in September 2022.