How carbon capture from the air could reshape the green transition

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If you look at the decarbonization landscape from a bird’s eye view, the divergence between the fortunes of different technologies is surprising.

For those who rely on small equipment that can be manufactured in factories (think solar panels), costs have plummeted and adoption has skyrocketed. Those that require large custom engineering projects, such as conventional nuclear plants, have suffered delays and cost increases. The problems with wind turbines also suggest that scale works best when it is manufacturing capacity that is scaled up, rather than product size.

Proponents of direct air capture (DAC) hope to harness the magic of the learning curve. This nascent technology sucks CO₂ out of the air and then stores it underground. The world’s largest plant, opened by Climeworks in Iceland, will capture 36,000 tonnes of CO₂ per year, approximately the amount emitted by 4,500 UK homes. At an estimated cost of $1,000 per ton of CO₂ today, it is also incredibly expensive.

However, unlike large-scale nuclear power, DAC plants are modular and made up of many boxes with fans and filters. That raises hopes for a completely different type of cost curve.

Take the boxes. Distributing their cost over the CO₂ they will capture throughout their useful life generates an investment cost of $330/tCO2, or one third of the total. However, as this kit moves from custom-made to scale-built, its price will drop dramatically. Add in improvements in energy efficiency and operating costs and, if DAC truly scales up to the multiple gigatonnes of capacity required by most net zero pathways, its cost may end up in the region of $100-150/tCO2 by 2050.

Of course, 25-year forecasts aren’t much more than lines on graphs. However, the CAD story seems broadly plausible and would make it competitive with some of the more expensive carbon reduction options.

For example, one of the (speculative) options to decarbonize long-haul flights is to make synthetic jet fuel using green hydrogen and then react it with CO₂ captured from the air. This is an expensive way to solve the problem: rough figures suggest it could cost $220 per ton of CO₂ avoided, twice as much as DAC.

It’s not hard to see why airlines might prefer local decarbonization options, which create a supply chain they can work with and even invest in. The current regulation also pushes them in that direction.

But those hard-to-shrink sectors would do well to support expanding the DAC. The projected cost decline could reduce the growing burden of the energy transition.

Video: The question of carbon capture | FT Climate Capital

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