Direct air capture needs innovation, says IEA

Direct air capture (DAC) is gaining momentum, but further innovation is needed to strengthen its case as a means of tackling climate change, the International Energy Agency (IEA) said in a report published on April 1. 

DAC technologies still require significant amounts of energy, and in the case of the liquid DAC method, the high temperatures needed mean that plants must use natural gas as their fuel. Solid DAC technology, on the other hand, can run on renewable energy.

Innovation that can enable renewables to provide high-temperature industrial heat would maximise the carbon removal potential of liquid DAC technology, the IEA said. 

DAC also needs to be demonstrated in different conditions, for example in extremely dry or humid climates, or where there is significant air pollution, the Paris-based agency said. While in theory the technology can be employed anywhere, to date it has been mostly developed in Europe and North America.

There also need to be innovations in the ways in which the captured CO₂ can be used, for example in developing synthetic aviation fuels. 

DAC costs are high today, with the IEA estimating that large-scale plants currently being developed have expenses of between $125 and $335 for every metric ton of CO₂ they capture. But with deployment and innovation, the cost could fall below $100 by 2030. but this will depend greatly on the level of public and private support for the technology.

The IEA stressed the need for DAC to be demonstrated at scale, for innovation across the DAC value chain to be fostered, CO₂ storage sites to be identified and developed and international certification and accounting standards for DAC to be established. There should also be improved understanding and communication of how DAC can play a role in delivering net zero, and greater international cooperation to help accelerate development, the agency said.