New drilling technologies could open new doors to geothermal energy and disrupt the entire energy industry.
Geothermal energy is already one of those technologies that make it possible to supply large quantities of energy without burning the slightest fossil resource, and without the slightest emission of greenhouse gases. But its applications are unfortunately limited to very specific geographical areas for the moment.
Specialists believe that this technology can still make considerable progress, but this involves digging very deep geothermal wells, well beyond the few tens of meters of the current channels. But from a certain depth, the hardness of the rock and the temperature become difficult to tolerate for drills.
To take geothermal energy to the next level, it is therefore necessary find an effective way to pierce the crust, or even the Earth’s mantle much deeper. The engineering challenge is enormous, but the payoff is worth it; with this approach, it would be possible to exploit a phenomenal amount of geothermal energy that could revolutionize the entire energy industry.
A high-tech microwave to vaporize the rock
And that’s where it comes in Quay, a satellite company of the prestigious MIT. Based on the work of the engineer Paul Woskovshe developed a concept based on a gyrotron. It is a device already used in many industrial sectors to heat materials remotely, particularly in the case of experiments on nuclear fusion.
Very vulgarly, it works a bit like a big laser; the objective is to focus an electromagnetic wave to concentrate all its power in a small space. The difference is that the gyrotron operates at a different frequency range; it emits microwaves instead of visible light.
The idea is very simple on paper: it consists in using very powerful gyrotrons to heat the rock until it is sprayed on site. This technique could make it possible to dig extremely deep geothermal wells – the company even speaks of deepest holes ever drilled!
For the moment, it is still only a concept. Even if the technology on which it is based seems already mature, it is another story to implement it in real conditions. And that’s precisely what Quaise will attempt to do with a grant from the US Department of Energy.
By the end of the year, it will test its first prototype. The objective will be to dig a hole ten times deeper » than Woskov during his solo work (this figure has not been disclosed). She will then move on to a second well, this time 100 times deeper than the original.
This step is not expected before 2024 since it will require major modeling efforts. But if Quaise passes this course, the firm will then have all the weapons in hand to approach the final stretch.
Ultimately, the company wants to reinvest in disused power stations. It will thus be able to reuse the existing infrastructure; enough to give a second life to these buildings. At this point it would suffice to convert the rest of the equipment and then dig down to a depth of about 20km — where the temperature systematically reaches several hundred degrees.
A fledgling but really promising concept
It would then be possible to do jump the geographical limits of geothermal energy. ” We believe that by drilling down to 20 km, we will be able to access these extreme temperatures from 90% of the planet “says the press release from MIT.
And it’s not just about availability. Having access to such temperatures at all times would make it possible to produce a very large amount of energy which could even compete with traditional power plants.
” At these temperatures, we produce steam with a temperature very close to, or even higher than, that found in coal or gas-fired power plants. “, explains the press release.
According to the researchers, this is also a sustainable approach. Once mature, it could replace nearly all coal globally and meet human energy needs for “ millions of years “.
This time is the right one?
Of course, we are still a long way from that. For now, the drilling technology itself is not even fully developed. Once it is, it will also be necessary to determine its environmental impact. It will then be necessary to develop new equipment to exploit these exceptionally deep wells, which will be anything but simple.
Despite everything, MIT is optimistic and believes that the first results could arrive very quickly. The technological bases are already well in place and all that remains is to integrate everything into a single efficient and reliable system. ” If we can solve these engineering problems, I think we will have a functioning plant within five or six years. “says the father of the concept.
This makes this technology particularly interesting in the current context. “ We have made incredible progress on renewable energy in recent years, but overall we are still largely not moving fast enough to meet the targets that will limit the impact of global warming. explain the researchers. The arrival of such technology would certainly be a big step in this direction.
It should however be take all these promises with a grain of salt. As always when an institution unveils a source of revolutionary energy. After all, it is no coincidence that Woskov’s work has long stood still; the technical challenge is enormous. But this approach has such great potential that it deserves to be explored in any case. We therefore give you an appointment in a few years to see if this research will have gone from concept to reality.