New Drilling Tech Could Be a Game-changer

A new drilling technology benefitting from fusion energy research shows promise for geothermal energy.

gyrotrons capable of generating continuous energy beams over a megawatt in power are now becoming available, and that's amazing news for deep drillers. "The scientific basis, technical feasibility, and economic potential of directed energy millimeter wave rock drilling at frequencies of 30 to 300 GHz are strong," wrote Ogilvy. "It avoids Rayleigh scattering and can couple/transfer energy to a rock surface 10¹²X more efficiently than laser sources in the presence of a small particle extraction plume. Continuous megawatt power millimeter-waves can also be efficiently (>90 percent) guided to great distances (>10 km) using a variety of modes and waveguide (pipes) systems, including the potential of using smooth bore coiled and jointed/ joined tubing."

"Thermodynamic calculations," he continued, "suggest a penetration rate of 70 meters/hour (230 ft/hour) is possible in 5 cm (1.97 in) bores with a 1-MW gyrotron that couples to the rock with 100 percent efficiency. Use of lower or higher powered sources (e.g. 100 kW to 2 MW) would allow changes in bore size and/or penetration rate."

Quaise plans to drill holes up to 20 km (12.4 miles) deep, significantly deeper than the Kola Superdeep Borehole – but where the Kola team took nearly 20 years to reach their limit, Quaise expects its gyrotron-enhanced process to take just 100 days. And that's assuming a 1-MW gyrotron.

At these depths, Quaise expects to find temperatures around 500 °C (932 °F), which is well past the point where geothermal energy takes a massive leap in efficiency. "Water is a supercritical fluid at pressures above 22 MPa and temperatures higher than 374 °C (705 °F)," said Quaise. "A power plant that uses supercritical water as the working fluid can extract up to 10 times more useful energy from each drop when compared to non-supercritical plants. Aiming for supercritical conditions is key to attaining power densities consistent with fossil fuels."

The next step is commercial genius: Quaise plans to take advantage of existing infrastructure like coal-fired power plants, which will eventually be mothballed as emissions restrictions become ever tighter. These facilities already have enormous capacities to convert steam into electricity, as well as established commercial operators and experienced workforces, and they come conveniently pre-connected to the power grid. Quaise will simply replace their current fossil fuel heat sources with enough supercritical geothermal energy to keep the turbines spinning indefinitely without ever needing another lump of coal or puff of methane.

Quaise expects to re-power its first fossil-fired plant in 2028, and then go on to refine and replicate the process all over the world, since the heat should be available absolutely anywhere on Earth with this drilling technology. There are somewhere upwards of 8,500 coal-fired power plants around the world, totaling over 2,000 gigawatts of capacity, and they'll all have to find something else to do by 2050, so the opportunity is clearly mammoth.

if this technology works as expected (and the crust doesn't find new ways to fight back against our intrusions), and the economics stack up, this new use for gyrotrons could ironically end up putting fusion reactors out of a job.

Importantly, it'll take up almost no space on the surface, in contrast to industrial-scale solar and wind. It'll also precipitate a global geopolitical shift, since every country will have equal access to its own virtually inexhaustible energy source, and it sure will be nice when big countries don't have to "liberate" the populations of smaller ones to gain access to energy resources.