Geothermal Power Plant Turns CO2 Emissions Into Solids

June 11, 2016

panorama hellisheidi[Image Source: Kevin Karjick/ UoC]

Many people still continue to question the legitimacy of man-made climate change, but most agree that the release of excess CO2 into the atmosphere is generally something that should be avoided or mitigated if possible. As clean energies like solar, wind, and wave power continue to grow in the worldwide energy sector, one geothermal power plant in Iceland is pioneering CO2 conversion technology.  Around 11 percent of Iceland is covered in Ice, but the nation sits atop an extremely active geothermal system. A team of engineers at the Hellisheidi power plant has spearheaded a unique method of CO2 injection that allows carbon dioxide to be chemically converted to a solid over the course of a few months from pumping it deep into a layer of volcanic basalt. Check out the video below to learn a little more about how the technology works.

Currently, the country gets most of its power from geothermal and hydroelectric sources, which means that for the time being, glacial and ice runoff is good for the energy grid. However, engineers see the problem; if the land continues to warm in the trend that it has, there eventually won’t be any runoff, and their energy grid will not be sustainable, according to Columbia University. Another problem that arises with the ice melting is the loss of the extreme weight from the ice layers that keeps pressure on the volcanic flows deep beneath the ground. If the ice were to completely melt, scientists fear that deadly eruptions could occur.

For the most part, the country is producing an amazing amount of energy, so much so that it has been proposed to run a giant extension cord to Europe to sell off all of the excess power that the 300,000+ residents don’t use. Reykjavik Energy runs the geothermal plant, and they have created a process that involves mixing carbon dioxide with hydrogen sulfide in water and then injecting the solution into the volcanic basalt below.

geothermal co2 plant[Image Source: Kevin Karjick/ UoC]

It has been known that carbon naturally precipitates with basalt for a while now, according to, but no one knew how fast the reaction could occur until this new groundbreaking research. Estimates of the reaction were previously in the range of hundreds of thousands of years, but the team of engineers studying this implementation of the reaction has found that 95 percent of the CO2 solidified in under 2 years, according to the study published here.

The project began by injecting 250 tons of the solution into the volcanic basalt to see just how fast the reaction could be created. Water samples were drawn from the basalt over the course of months, and through measurements of the carbon isotopes in the water, the team was able to gauge the success of the experimentation.

co2 geothermal rocks[Image Source: Kevin Karjick/ UoC]

This injection technique isn’t going to solve the world’s CO2 problem, as in order to mitigate one ton of CO2, it has to be mixed with 25 tons of water. Sea water is a viable alternative to freshwater sources, but in order to compensate for even a small country’s yearly output, it would take up too much water. This process is groundbreaking in terms of scope for carbon dioxide disposal, and it could serve to further prove how carbon emissions could be disposed of moving forward in the energy sector.

SEE ALSO: Ten major geothermal power resources