A new study published by the Oxford Institute for Energy Studies is examining direct air capture and how to scale this novel technology. The study is called Scaling Direct Air Capture (DAC): A moonshot or the sky’s the limit? And is authored by Peter Webb, Hasan Muslemani, Mark Fulton, and Nigel Curson.
As the world is rapidly exhausting its carbon budget, methods to remove carbon dioxide from the atmosphere are necessary to reverse climate change. Direct air capture is a technology that captures CO2 directly from the atmosphere and coupled with geological storage (DACCS) has recently emerged as one of the main carbon dioxide removal (CDR) methods with high potential to help us reach true net zero.
If deployed at scale, DACCS results in ‘negative emissions’ which would preclude the need for riskier options to abate emissions like geo-engineering. The study assesses the technical, engineering, materials and resource requirements needed to take the technology from its current megaton level of deployment to the gigaton level needed to achieve climate targets by 2050.
The paper highlights that as of end of 2022, annual GHG emissions are relatively stable or increasing slowly at 55 GtCO2 annually, while the remaining carbon budget for a 1.5°C scenario is estimated at 380 GtCO2. The world’s carbon budget for the 1.5 target is expected to be spent before the end of the decade which brings the need for much more rapid emissions cuts coupled with carbon removal acceleration.
Current short-term projections are for direct air capture to deliver some multiple of 1 million tons (Mt) of capture capacity before 2030. The analysis assesses the power requirements and storage capability of 1Mt units of CO2 capture. To deliver around 1 Mt/year of CO2 sequestration is generally thought to require around 2 terawatt hours (TWh) per year of installed power generation.
The focus is on non-fossil and net-zero power. The 2 TWhs are equivalent to the total annual output of a 230MW generation facility with a capacity or load factor of 100%. The technical aspects of the challenge of scaling DACCS from 1Mt to 1Gt by 2050 are also assessed. The study identifies the physical and geographic power and carbon storage requirements and tests their scalability.
The report provides numerous data and analyses of key requirements for scaling DACCS and concludes that the technology and materials to reach 1Gt of capture capacity by 2050 exist. However, it says that to make a climate-relevant impact, scaling to 5Gt by 2070 would be necessary.
Other key takeaways are that the scale of 1Gt of capacity by 2050 would be similar in scale to the existing refining industry, in addition to 2-4% of future power generation, and storage activity equivalent to one third of the current gas extraction industry.