Hellisheidi is not just an accomplished provider of green energy. It is also the site for a scientific breakthrough; an experiment to capture carbon dioxide (CO2) and turn it into stone
The Hellisheidi power station, 25km (15 miles) outside Reykjavik, is Iceland’s main geothermal plant, and is one of the largest in the world
“This is a volcanic area. We harness the volcano’s internal heat to generate electricity and provide hot water for the city’s heating system, our swimming pools and showers. We Icelanders like our showers really hot!”
Called CarbFix, the project is pioneered by an international consortium led by Reykjavík Energy, the French National Centre for Scientific Research, the University of Iceland and Columbia University, with funding from the EU.
Since experiments began in 2014, it’s been scaled up from a pilot project to a permanent solution, cleaning up a third of the plant’s carbon emissions.
With rising concentrations of atmospheric CO2, scientists have been testing “carbon capture and storage” (CCS) solutions since the 1970s.
CarbFix, however, stands out among CCS experiments because the capture of carbon is said to be permanent – and fast.
The process starts with the capture of waste CO2 from the steam, which is then dissolved into large volumes of water.
“We use a giant soda-machine”, says Dr Aradottir as she points to the gas separation station, an industrial shed that stands behind the roaring turbines.
“Essentially, what happens here is similar to the process in your kitchen, when you are making yourself some sparkling water: we add fizz to the water”.
The fizzy liquid is then piped to the injection site – otherworldly, geometric igloo-shaped structure 2km away. There it is pumped 1,000m (3,200ft) beneath the surface.
In a matter of months, chemical reactions will solidify the CO2 into rock – thus preventing it from escaping back into the atmosphere for millions of years.
At the University of Iceland, research around CarbFix has been continuing since its pilot phase.
A desk-size replica of the pipes and pumps in Hellisheidi in a state-of-the-art lab allows Prof Sigurdur Gislason to scrutinize the process.
It needs over 25 tonnes of water per tonne of CO2,” says Prof Gislason. “In Iceland we are blessed with lots of rain, but if you are doing this on the basaltic areas in India… their water is very precious”.