Carbon Underground
Carbon Underground
Geothermal power plant Hellisheiði
Carbon Underground
Geothermal power plant Hellisheiði

Turning danger into stone under the ground

Driving south from Reykjavík, one cannot help but notice the steam coming from the extensive infrastructure around the Hengill volcano. This once pristine geothermal area is criss-crossed with roads, boreholes and pipelines that are fixtures of the Hellisheiði geothermal power plant. Iceland is dotted with power stations like this one, and countless kilometres of pipelines wind through the landscape. Each of such plants consists of several wells that allow heat to pass from the earth’s core into our world.

The characteristic hissing of steam is far from the only sound that geothermal power produces. The sound reveals just how complicated the process is. It is commonly presented as a prototype of sustainability, environmental friendliness, clean energy and carbon-free production. But beneath the surface lies a different face of our efforts to harness one of the largest untapped sources of energy.

The individual wells pierce through geological layers in different parts of the country in order to bring heat to homes, pavements and saunas. But by drilling deep into the ground we undermine geological stability, causing earthquakes and releases harmful gases and substances hidden in the earth’s bowels into the air. The smell of hydrogen sulphide and sulphur that goes hand in hand with geothermal power production is locally called the “Icelandic perfume”.

Hellisheiði also produces a different kind of hissing than that of steam. The source is the Carbfix technology, which turns gas into stone. The local basalt bedrock allows it to store CO2 underground in a form other than gas. The technology captures CO2 by injecting water into the pores of the underground rock. There, the carbon dioxide reacts with the rock and gradually turns into rock itself.

Iceland and the surrounding oceans have the capacity to hold vast amounts of CO2, thanks to their bedrock formed by millions of years of volcanic activity. The ambition of local government and businesses is therefore to bring carbon dioxide from other parts of Europe to the island and specialize in carbon storage. The future will show whether this is an effective approach to climate crisis and whether we can buy time in this manner – until the day when we are able to limit CO2 production. Meanwhile, injections into the bedrock have disturbed the Hengill volcano due to hundreds of earthquakes caused by this technology’s treatment of the earth.

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Hellisheiði: Turning the danger into stone

The extensive operations under the earth's surface are apparent at first glance due to countless kilometers of pipelines that criss-cross the volcanic landscape in geometric patterns long before the Hellisheidi geothermal power plant itself emerges on the horizon. The thick white clouds of steam above its low building surrounded by sophisticated systems of energy capillaries evoke a fairly light production process. However, the microphones pointed at the turbines and transmission equipment attest to the immense power with which the Earth’s interior heats the water and which we reach through thousands of miles of boreholes. But Iceland's largest and newest geothermal power plant is actually the site of a completely different process, characterized by a sound very unlike the different kinds of humming emitted by the turbines. In shimmering domes reminiscent of space stations dotting the area, carbon dioxide is being pumped into underground caverns to fossilize forever. This emergency climatic solution takes on the form of quiet, soothing soundscapes. The fluidity and serenity of the soundscape evokes the hope that an elegant solution to the climate crisis is emerging from the bowels of the earth in a ghostly landscape between volcanoes shrouded in steam. But this is only an uncertain and shaky beginning of a long journey.

Field notes