The same fracking techniques that sparked fierce protests in the UK are being repurposed for geothermal energy – a renewable source that is winning rare bipartisan support in the US Congress.
Geothermal energy makes use of the natural heat below the Earth’s surface, and next-generation technology can now access hotter, deeper and more varied locations than ever before. In April, US senators from both parties introduced the Next-Generation Geothermal Research and Development Act, which would direct the Department of Energy to support the development and commercialisation of enhanced geothermal systems (EGS).
“Fracking techniques repurposed for geothermal energy gain bipartisan US support, but UK controversy lingers.”
EGS involves fracturing underground rock hydraulically – better known as fracking, a technique that became controversial in the UK during the oil and gas industry’s exploration. “It’s the same techniques and up to a point it’s the same industry as well,” said Gernot Wagner, a climate economist at Columbia Business School. But “from a climate perspective, there’s a huge difference,” he added.
Wagner argues that the risk of seismic activity from creating cracks underground is outweighed by the benefits of an energy source that is renewable, always-on and large-capacity. “Based on where we are, moving much faster, much bigger in the direction of using much more geothermal, frankly, is all good news,” he said.
Some US states are already accelerating permits for geothermal plants. The low greenhouse gas emissions appeal to liberals, while conservatives like the energy independence and use of drilling technology familiar in the oil and gas industry.
To go faster and deeper will require advances in drilling equipment that can break through hard rock at high temperatures. One company, Quaise – with roots at the Massachusetts Institute of Technology – is developing millimetre wave drilling, which uses electromagnetic waves similar to microwaves. “Sending electromagnetic waves in the microwave millimetre wave spectrum to essentially melt and vaporise through the rock,” explained Harry Kelso, Quaise’s communications manager.
Traditional geothermal energy has been limited to hotspots where very hot rocks are easily accessed. Millimetre wave drilling, Kelso said, “enables you to access super-hot geothermal” almost anywhere. If the economics can be made to work, the abundant heat beneath our feet could become a major part of the energy mix – even in countries like the UK, where fracking left a legacy of distrust.