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The hunt for heat: Drilling the deepest holes on Earth
Currently only 32 countries in the world have geothermal power plants in operation. There are fewer than 700 power plants around the world, generating around 97 Terawatt hours (TWh) in 2023 between them. That is less than half the amount of electricity generated by solar in the US alone and far short of estimates for the potential contribution that geothermal could make to the global energy mix. Some estimate that geothermal could contribute around 800-1400TWh of electricity annually by the middle of the century with a further 3,300-3800TWh per year of heat.
One reason geothermal is not more widespread is the high upfront investment needed to extract that energy. But physically reaching it has also been beyond us so far. One major hurdle is that conventional rotary drills – even those tipped with diamond – are ill-equipped to excavate to the kind of depths needed to access these kinds of temperature. In the mysterious deep underworld of uncertain geology, extreme temperatures and huge pressures, drill components can fail frequently, while keeping holes from becoming blocked is a constant battle.
Quaise Energy, a spin-off from the Massachusetts Institute of Technology (MIT), for example, are aiming to drill holes as deep as 12 miles (20km) to access temperatures of 500C (932F) or more. To do so, they are turning to a tool that draws on years of research into nuclear fusion power. “While others are putting shovels in the ground, we’re putting microwaves in the ground for the first time,” says the company’s co-founder Matt Houde.
Slovakia-based GA Drilling, meanwhile, is exploring a different high-energy drill technology to bore into the Earth’s crust. It is using a pulse plasma drill, based on very short high energy electric discharges that disintegrate rock without causing it to melt. This avoids creating any viscous molten rock, which can be difficult to remove and can stop drill bits penetrating further. “Since the process is very swift with short shocks crumbling the rock, there isn’t time for melt to form – so the need to pull up and replace the bit is greatly reduced,” says Igor Kocis, chief executive and chairman of GA Drilling. “Five to eight kilometres (3-5 miles) is a target for our current development programme – and later 10km-plus,” he adds. “These depths will allow nearly universal access to geothermal power.”
HydRegen raises ÂŁ2.6 million to clean up the chemical manufacturing and pharmaceutical industries
HydRegen, the Oxford-based biotechnology company enabling sustainable chemical manufacturing, has secured a ÂŁ2.6 million investment as part of its latest fundraise, led by Clean Growth Fund, the UK clean-tech venture capital fund.
The new investment from Clean Growth Fund, alongside a group of existing investors, will support the commercial development and deployment of HydRegen’s technologies through the next 18 months. HydRegen plans to license its technology to companies manufacturing pharmaceutical and chemical products around the world. To do this, it also plans to expand its team over the next 12 months.