The arguments surrounding fracking are familiar to most of us by now. But we’re hearing the distant rumbles of another big energy argument to come, and it looks set to be just as fierce.
Right now, geothermal energy is dwarfed by other power sources. But its development in the new form of “enhanced geothermal systems” (EGS) could potentially make it far more important.
The Economist recently described EGS as “geothermal fracking”, saying the process is extremely similar: drilling and injecting a highly pressurised water and chemical mixture into the ground in order to break open cracks in rock beneath. It might sound exactly like fracking, but the geothermal industry insists it’s a world away.
Regular geothermal energy is already powering most of Iceland - having a few active volcanoes around is helpful if you want to power an entire country with this clean source of energy. It’s normally generated using pre-existing hot water and steam from natural sources in the ground.
But with EGS, energy companies are now looking at generating geothermal energy from dry wells in places that aren’t exactly well-known for their volcanic activity.
Cornwall, England, is one such place. It might sound unlikely, but it has long been seen as an ideal location for an EGS plant because of granite outcrops in the earth, relatively close to the surface
UK-based EGS Energy has planning permission for a £35million “hot rocks” geothermal plant, to be built on the same site as Cornwall’s Eden Project. The company has said that energy created by an EGS project could power the Eden buildings, and any surplus energy could be fed into the national grid. The project, initially estimated to be complete by 2012, is however still in the planning stages.
Believe it or not, the US is currently the world leader when it comes to geothermal energy generating capacity, with more than Iceland - about 3.4 gigawatts - already in operation.
This however only accounts for about 0.4 percent of all the country’s electricity. The department thinks that with EGS, that figure could eventually rise to 10%.
Proponents say EGS could make this clean power source cheaper and more widely available for many other countries that otherwise wouldn’t be able to use it.
Conventional geothermal fields not only require very specific geological conditions, but cost millions of pounds (or dollars) to develop, and about one in two wells fails. With EGS, failure rates could be reduced and some say the size and life of existing geothermal fields could also be extended.
But environmental groups and many people living near test sites think these potential benefits come at too high a price. In fact, many are convinced that EGS is the equivalent of geothermal fracking.
It’s not surprising that the industry is so quick to reject the comparison, since fracking has been the subject of vigorous campaigning and furious public demonstration in many countries and is even banned or restricted in some.
But it’s a fact that EGS can trigger earthquakes. An early project on a seismic fault in Basel, Switzerland was scrapped after several quakes, and a group of Swiss scientists recently found that earthquakes, though mostly minor, are guaranteed with EGS.
Many have said the experience at Basel is a good enough reason to avoid EGS altogether. But the US Department of Energy remains in support of the idea, and new test projects are also going ahead in France, Germany and the UK.
“It’s easy to generate a lot of fear. You can scare people about things without providing much solid information,” said David Stowe, communications director at US energy firm AltaRock. “The Basel story is dredged up over and over again, but we have learned from it, and it is pretty easy to put safeguards in place that will severely minimise risk.”
The company says its EGS sites are constantly monitored to prevent earthquakes. Stowe described the monitoring process as “an intricate operation.”
But for some, this comes as little comfort.
Altarock have been accused of a lack of transparency by local residents near the company’s demonstration project in central Oregon after it was revealed that, rather than injecting “cold, clean groundwater” into the wells, as an AltaRock project manager told Oregon Public Broadcasting, they will actually be injecting a far less refreshing-sounding mixture of water and “industrial chemicals… including naphthalene, safranin, rhodamine, lithium, cesium, rubidium, fluorescein, tobermorite, polymerized plastics, secret Altavert fluids, and other compounds”
The company responded by pointing out that the chemical mixture used is “very, very dilute.”
AltaRock also claims the technology used at this site can extract six to ten times as much power from a field as older geothermal techniques.
As with fracking, there are concerns about leakage and spills of the water and chemicals used for EGS causing groundwater and soil contamination.
In the past two years alone natural gas fracking has caused numerous surface spills, including several that have contaminated groundwater, according to Popular Mechanics magazine.
However a clear difference is that, unlike the now-familiar process of fracking, this new type of “fracking” for geothermal energy doesn’t involve the burning of hydrocarbons.
Many critics have said that the biggest problem with fracking for shale gas and oil lies not in the drilling process, but in taking hydrocarbons out of the ground and burning them, increasing global carbon emissions.
EGS technology meanwhile is described as being low-carbon or carbon-neutral. While the case for increased use of low carbon technology gets ever stronger, it remains to be seen whether this will be enough to swing the political argument in the geothermal power companies’ favour.
Right now, the testing of EGS is still in the relatively early stages. Geothermal companies have comparatively little data to put forward from previous projects, which could also make it harder for them to put forward a compelling argument.
The public debate on EGS is yet to begin, and so far it seems like this one will be at least as fiercely argued as that over fracking for shale gas and oil.