A Geothermal Power Plant in Iceland Has Achieved Negative Emissions – Removing Carbon Dioxide From the Atmosphere and Turning it Into Rock Deep Underground. The Case for Carbon Capture Based on New Successes
Akshat Rathi | Quartz
Iceland is cold. But it sits atop one of the world’s hottest underground regions, giving the country the ability to tap into a massive store of geothermal energy held by live volcanoes beneath Icelanders’ feet. Drill down only a few hundred meters, and trapped water will come gushing out as high-temperature steam. It’s easy enough to turn that into electricity: just run it through a turbine to drive an electrical generator, like we’ve been doing for over 100 years with any kind of steam.
The only problem is drilling into these volcanic regions also releases carbon dioxide, the major greenhouse gas driving global climate change. Geothermal power is still very clean, producing just 3% of the emissions of a coal plant generating the same power. But Iceland wants to reduce its emissions all the way to zero.
The solution can be found at the Hellisheidi geothermal power plant, Iceland’s largest, just outside the capital Reykjavik. Since 2014, the plant has been extracting heat from underground, capturing the carbon dioxide released in the process, mixing it with water, and injecting it back down beneath the earth, about 700 meters (2,300 ft) deep. The carbon dioxide in the water reacts with the minerals at that depth to form rock, where it stays trapped.
In other words, Hellisheidi is now a zero-emissions plant that turns a greenhouse gas to stone.
This October, it went a step further, partnering with Climeworks, a Switzerland-based startup, to install a machine that sucks carbon dioxide out of the air. That gas is also sent underground, where it, too, eventually turns to rock. The result is a “negative emissions” power plant that literally subtracts carbon dioxide from the atmosphere. As of this writing, the Climeworks machine has already pulled out more than 5 metric tons of carbon dioxide from the air and injected it underground, the equivalent of burying the annual carbon footprint of a household in India.
Critics laughed at those pursuing a moonshot in “direct-air capture” only a decade ago. Now Climeworks is one of three startups—along with Carbon Engineering in Canada and Global Thermostat in the US—to have shown the technology is feasible. The Hellisheidi carbon-sucking machine is the second Climeworks has installed in 2017. If it continues to find the money, the startup hopes its installations will capture as much as 1% of annual global emissions by 2025, sequestering about 400 million metric tons of carbon dioxide per year.
For decades, certain scientists have hoped carbon-capture technologies, deployed at large scales, could save humanity from catastrophic climate change by providing a bridge to a future in which we’ll have enough capacity to create, store, and supply all the world’s energy from only renewable sources. Now that seems imminent. The 2015 Paris climate agreement set a number of goals designed to keep global average temperatures from rising above 2°C as compared to pre-industrial levels—a threshold beyond which there may be irreversible changes to the climate. The foremost authority on the matter, the International Panel on Climate Change, has modeled hundreds of possible futures to find economically optimal paths to achieving these goals, which require the world to bring emissions down to zero by around 2060. In virtually every IPCC model, carbon capture is absolutely essential—no matter what else we do to mitigate climate change.
But carbon-capture technologies have a tortured history. Though first developed nearly 50 years ago, their use in climate-change mitigation only began in earnest in the 1990s and scaling them up hasn’t gone as planned. Over the past decade, billions of dollars have been spent on carbon-capture projects that have not materialized. The most recent failure was the $7.5 billion Kemper Project in Mississippi, whose owners earlier this year announced that instead of finishing the planned low-emissions coal plant, they would just turn it into a natural-gas plant.
Those fiascos have provided ammunition to environmental activists who argue that carbon-capture technologies create a “moral hazard,” making us complacent about the ongoing use of fossil fuels and extending the time we take to wean off them. At the most recent climate talks in Bonn, Germany in November, protesters thronged the only panel the US was officially hosting, because some of the panelists were arguing for the use of carbon capture when burning coal. “Clean coal is a myth!” they shouted.
My initial perception of carbon capture, based on what I had read in the press, was to side with the protesters. Carbon-capture technologies seemed outrageously expensive, especially when renewable energy is starting to get cheap enough to compete with fossil fuels. At the same time, my training in chemical engineering and chemistry told me the technologies were scientifically sound. And some of world’s most important bodies on climate change keep insisting that we need carbon capture. Who should I believe?
The question took me down a rabbit hole. After a year of reporting, through visits to large and small carbon-capture plants around the world, and conversations with more than 100 academics, entrepreneurs, policy experts, and government officials, I’ve come to a conclusion: Carbon capture is both vital and viable. Its mass deployment remains a challenge, but not for the reasons that many environmentalists commonly cite. Clearing up those misunderstandings could offer hope in a world full of doom-and-gloom climate stories.