Clean Geothermal Energy: Cost-competitive With RE, Fossil Fuels

Co-founder of geothermal startup Quaise Energy stated that clean geothermal energy that is stored beneath our feet is a billion times greater than our annual energy needs as a planet.

Clean Geothermal Energy Cost-competitive With RE, Fossil Fuels

“If we can drill deep enough to reach the resource’s mother lode, clean geothermal energy—the heat under our feet—could potentially be as affordable as other renewables and even fossil fuels.” One speaker at the Society of Petroleum Engineers’ (SPE) geothermal conference last month stated as much .

Other speakers talked about the oil and gas industry’s expanding interest in the subject, the main difficulties it faces, and potential solutions.

Geothermal 2023: Realizing the Ambition was put on by the SPE chapter in Aberdeen, Scotland. The conference, which was held over two days rather than one in 2022, was organised by Kirsten Pasturel, who noted that the event itself was a sign of growing traction in the geothermal market.

According to Ann Robertson-Tait, president of GeothermEx, more oil and gas companies have begun “really digging into the geothermal space,” which is a trend she has observed over the past year.

Why? “Perhaps more than any other renewable sector, the oil and gas [sector] is relevant to geothermal energy. Consider the following: exploration, geoscience, wells, completions, etc “Pasturel said. Oil and gas can undoubtedly help with many puzzle pieces, but it doesn’t have all the solutions for scaling geothermal successfully.”

Matt Houde, a conference speaker and the co-founder of the geothermal startup Quaise Energy stated that the clean geothermal energy that is stored beneath our feet is a billion times greater than our annual energy needs as a planet.

Right now, however, we can’t drill deep enough to unlock the mother lode of the resource, which is some two to twelve miles beneath the Earth’s surface. The rock is so hot (over 374 degrees Celsius, or 704 degrees Fahrenheit) that if water could be pumped to the area, it would become supercritical, a steam-like phase that most people aren’t familiar with.

If supercritical water could be pumped above ground to turbines that could use it to generate electricity, it would be a very effective energy source because it can carry 5 to 10 times as much energy as regular hot water. In comparison to a conventional hydrothermal well, this could result in “a step change improvement in terms of the power output that can be produced,” according to Houde.

There is therefore enormous potential, but it is expensive to access deep clean geothermal energy. The conditions miles below cannot be handled by conventional drilling techniques.

As a result, according to Catherine Hickson, CEO of Alberta No. 1 and keynote speaker at the conference, “a number of projects in the last few years have been focused on improved drilling.” “If we want deep geothermal and higher temperatures, the drilling costs make geothermal a very expensive proposition.”

Presenters at the conference addressed the drilling challenge, focusing on oil and gas “movers” in geothermal drilling. Representatives from Roemex, Adrilltech, and Expro described a variety of approaches to cutting costs.

Tony Pink, VP of Subsurface Energy Technology at NOV, discussed the novel drilling technologies being developed by their companies. Quaise Energy proposed millimeter-wave drilling, which uses energy-matter interaction to melt and vaporize rock deep below.

The Quaise technology takes advantage of conventional drilling technologies to drill down through surface layers to deep basement rock. NOV is also looking at non-traditional technologies such as the particle impact drill, which fires a two-millimeter steel shot out of a bit at 12 million a minute. The shot goes down the hole, accelerates out the bit, and then comes back to the surface and is recycled.

According to Houde, the Quaise millimetre wave process is largely independent of depth; therefore, drilling costs will scale with depth linearly rather than exponentially, as is the case with conventional technologies.

In the most conservative scenarios, where we aim for those temperatures at a depth of 10 to 20 kilometres, we believe we can achieve a levelized cost of energy (LCOE) of less than $40 per megawatt hour when combined with the power potential of superhot geothermal wells.

He proposed that other elements, like drilling at extremely hot temperatures at shallower depths, might lower the LCOE to under $20 or $30 per megawatt hour. According to the study, “it becomes incredibly competitive with today’s energy infrastructure as well as the incoming energy infrastructure—primarily wind and solar—being brought online as part of the energy transition.”

Houde and Pink both had a positive outlook on the future. Pink recalled that drilling an oil well in the Permian Basin took between 80 and 90 days in 2006. 15 days from now, they will be drilled. “We can do it again with geothermal because we’ve done it with unconventionals.”

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