I fell in love with Iceland after my partner and I first ventured there in 2005 to see our favorite band, GusGus, perform at the SXSW of the Arctic Circle, Iceland Airwaves. It was a magical experience of food, continental plates, glaciers on top of volcanoes, and partying with Bjork. On our fourth trip a few years ago, over New Year’s, we toured the Golden Circle with the promised bonus of visiting the Hellisheidi geothermal power plant (my partner is an engineer that works on power plants). However, the dang visitor center was closed when we got there.
In March 2022, we traveled back to Iceland to enjoy the 25th anniversary concert of GusGus in the capital city, Reykjavík. After lamenting the earlier missed opportunity of visiting the geothermal plant, we thought, what the heck: let’s day rent a four-wheel drive and see that dang plant. Even better, a carbon sequestration company—Climateworks—had set up a pilot study at the same location. Maybe we could see that too!
When we awakened the following day, the weather outside was frightful, but armed with a four-wheel drive (with a carbon offset, just like our flight on Iceland Air) and the naïveté of southerners, we disembarked. When we arrived at the geothermal plant some 30 kilometers east of town, we were the only visitors. Not only did we have the place to ourselves, but the on-site staff were all geologists (it’s too brutal to work outside during winter). So we had educated folks there to answer our questions.
(left) Hellisheidi Geothermal Power Plant (right) Hard hats and safety vests inside the power plant. Photo credit: Robert E. Mace
There were some surprises from our visit. First, geothermal in Iceland is once-through, open-loop water, meaning groundwater from the geothermal zone is produced, harvested of its heat, and then discharged (which is why the Blue Lagoon exists). Iceland does not do closed-loop geothermal, which is much more water efficient. The other surprise was that geothermal waters are laden with carbon dioxide, so geothermal is not necessarily carbon neutral. The third surprise was that the plant had been dabbling with carbon sequestration for a decade, long before Climeworks showed up.
For the geothermal plant, Carbfix, harvests the produced carbon dioxide, bubbles it into water (what I call Topo Chico-fication), and then injects it into the fractured basalt below. The CO2 (carbon dioxide gas) in that water then interacts with the geology to precipitate out as carbonate. The visitor center has an excellent display showing how they do this, including cores through injection zones showing how the carbon dioxide has reacted with the basalts to create limestone.
(left) An exhibit about carbon sequestration displayed at the power plant. (middle and right) Rock cores recovered during drilling at the CO2 injection site. The white bits show where the limestone has precipitated into the “holes” or fractures in the basalt. Photo credit: Robert E. Mace
That precipitated limestone also clogs the fractures and porosity that carry the fizzy water into the basalts. When I asked how long an injection well lasts, a geologist answered, “A couple of years.” That makes this type of sequestration expensive (among other factors). As scientists and engineers learn more, perhaps they can better optimize the process.
Sadly, Climeworks was not open to the public for tours. Nevertheless, I wanted to get close to get a photo. My partner asked about the alarming red and yellow signs in Icelandic we passed as we careened down a one-lane drifty road to the atmospheric carbon dioxide harvester. They looked like festive welcome signs to me. My partner—always a rule-follower—was getting nervous, but we made it to the small parking lot out front, and I stepped out to get a few photos without creating an international incident. The demonstration plant wasn’t operating during our visit, but people were working on it. I don’t swear to it, but I thought I saw the Climate Bandit—always one step ahead—peeking out from a window while drinking a Topo.
Outside of the Climeworks office. Photo credit: Robert E. Mace
The technology pulls carbon dioxide out of the air and then piggybacks on the geothermal plant’s carbon sequestration wells (which are housed in those futuristic igloos). The approach is not without controversy and would be expensive at scale. But my philosophy is that we don’t know until we know. And we won’t know if it’s affordable until we need it. What’s expensive today may be affordable in the future, either due to technological advances or the increased value of the need.
People are also concerned about the moral hazard: if we don’t have to reduce emissions due to the promise of these technologies, then we won’t. But we’ve already not reduced emissions enough. So perhaps this tech might be helpful. Regardless, it’s dang cool, and I, for one, had a big, cold smile on my face after seeing it.
This was super interesting. Thanks!