Underground Energy

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The invasion of Ukraine has forced European leaders to look at their dependence on Russian gas. Some countries are trying to find alternatives like Liquid Natural Gas (LNG) and extending the life of coal-fired power stations. But for now, much of Europe continues to buy Russian gas and so fund Vladimir Putin’s war machine. It may not offer an immediate solution to the fast-rising cost of fossil fuels – but literally everyone on Earth is standing right on top of a green, sustainable and virtually limitless power source; geothermal energy. A US company is now planning to dig the world’s deepest hole in order to tap an inexhaustible supply of energy from the Earth’s crust.

MIT-spinoff Quaise Energy has raised $63 million to bore a record-breaking 20km below the planet’s surface – nearly twice as far as the deepest holes ever made – where temperatures reach up to 500oc. Quaise Energy describes the project as a “necessity, not an option”, offering a source of energy that is as powerful as any fossil fuel and as clean as solar, wind or hydro.

The firm hopes to have the first drilling platform live by 2024, the first wells producing up to 100 megawatt of geothermal energy by 2026, and fossil power plants repurposed to use geothermal energy by 2028, delivering clean energy around the world.

Being able to tap into a globally available supply of geothermal energy requires drilling much deeper into the Earth than currently possible. The Kola Superdeep Borehole in Russia holds the record for deepest produced hole, going down about 11 kilometres, but even that isn’t enough for Quaise Energy.

They suggest that drilling would need to go down to about 20 kilometres  below the surface in order to reach rocks hot enough to power massive power plants. The problem is, when a drill goes below the base rock, temperatures and pressure start to increase, which in turn damage the drill and stop it going any deeper .Quaise’s solution is to not use a physical drill at all, but rather turn to a sci-fi inspired ‘beam’ technology, that vapourises the rocks in its path.

Geothermal energy is already in use in areas where pockets of naturally occurring heat sources are close to the surface and in easily accessible locations. The problem is, for them to be viable they also have to be close enough to a power grid, making geothermal power plants relatively rare.

When they do work, they provide a totally reliable, round-the-clock power source, that continues going, unlike other renewables, such as wind and solar. If the sun isn’t shining, or wind doesn’t blow, then power isn’t generated, but with geothermal energy, the rocks under the Earth are always hot.

Currently, geothermal supplies about 0.3 per cent of global energy consumption, but Quaise believes its technology can see the figure quickly  increase. “A rapid transition to clean energy is one of the biggest challenges faced by humanity,” said Arunas Chesonis, Managing Partner of Safar Partners, the firm behind the fundraising round. “Geothermal energy can provide a lot more power using fewer resources. “Quaise’s solution makes us optimistic for a future where clean, renewable energy will secure the future of our planet.”

Being able to drill deep into the surface, from anywhere on the planet, without expensive, and easily damaged drills, is a game changer for renewable power, according to the team behind the technology. It would allow for geothermal power stations to be placed almost anywhere, and even replace existing fossil fuel stations with geothermal energy sources.

The company plans to use its novel drilling technology to re-power traditional power plants, saving infrastructure costs and utilising the current workforce to accelerate the shift towards a sustainable energy industry.

But you don’t have to go as deep as Quaise plans to. The Netherlands, and some areas in France and Germany, are already using shallower holes to heat up water for homes and agriculture. In 2020, the Netherlands extracted enough energy to heat almost 120,000 homes. The Dutch government hopes this capacity can be expanded to a quarter of the country’s demand for heat by 2050,

Sri Lanka has seven major hot springs with outflow temperatures of up to 72oc. Hot enough for showers and cooking eggs – but with the addition of heat exchangers, this natural energy could be used to generate electricity. Worth thinking about the next time the lights go out.

By Michael Gregson