For the people in a scenario team, it’s always exciting when something that you have discussed in your work suddenly starts to appear. It’s even more exciting when it happens in the company that you work for. So it is with direct air capture (DAC). Last week Shell announced it has taken the decision to build a DAC industrial-scale demonstration unit at the Shell Technology Center Houston (STCH), in the USA. With a targeted start-up in 2025, the company aims to prove the technical viability of its in-house developed solid sorbent technology.
The Shell announcement is but one of several DAC announcements in recent months, with many of the projects in the USA where the Inflation Reduction Act (IRA) is pumping over a billion dollars into this nascent technology. Also last week The U.S. Department of Energy (DOE) announced that DAC projects in Texas and Louisiana to remove more than 2 million tonnes of carbon dioxide per year from the atmosphere will get over $1 billion in federal grants. Two major projects the DOE selected are Project Cypress in Louisiana, run by Battelle, Climeworks Corporation and Heirloom Carbon Technologies; and the South Texas DAC Hub in Kleberg County, Texas, proposed by Occidental Petroleum’s subsidiary 1PointFive and partners Carbon Engineering Ltd (whom Oxy have subsequently announced they are acquiring) and Worley.
I have written about DAC in several posts, but it’s worth revisiting this in the context of these announcements and through the lens of The Energy Security Scenarios. Two scenario stories are presented, Sky 2050 and Archipelagos. They explore the tension that now exists between what world leaders promise on climate change at events such as COP26 in Glasgow and the reality those same leaders face when near term energy system disruption occurs, and immediate decisions must be taken to address the situation.
- Archipelagos depicts a global narrative of shifting political winds driving the transition away from fossil fuels. Despite encountering challenges, the pace of the transition accelerates due to heightened security concerns and competition. This scenario envisions a world where energy security takes precedence over emission management.
- Sky 2050 explores a world in which long-term climate security is the primary anchor. Society rapidly moves towards net-zero emissions but doing so requires major interventions from policymakers in the energy system.
In the Archipelagos story there is no DAC, at least not until the tail end of the century when it just starts to emerge. This is a story where current efforts come to nothing as other issues take priority – although not without consequence. But in Sky 2050 the technology flourishes and by 2100 it has made a material difference to the temperature outcome. However, it’s not a simple journey. Today there is a lot of discussion around DAC, but it remains a nascent and relatively expensive technology with capture costs of several hundred dollars per tonne of CO2, although estimates and statements of cost vary widely. The goal is to progressively bring down the cost, perhaps to around $100 per tonne CO2, but it is nowhere near this level today. So in Sky 2050, even though DAC emerges, nothing truly material happens until 2040, still over 15 years away. This is because new technologies in the energy sector typically take a generation (20+ years) to mature before material change is visible. DAC first appeared at least a decade ago, if not more, and is now only just being turned into the first larger scale projects. Compare this to solar PV, it first appeared in the late 1950s, with the first commercial power generation installation (6 MW) in 1983. In 2022 solar PV produced about 5% of global electricity, 40 years after the first project.
In Sky 2050 the first material appearance of DAC (5 million tonnes per annum globally) is in 2040 and this is for fuel synthesis, not for geological storage and therefore permanent removal. Presumably this is where the business model lies, despite the economic pull from the IRA. Airlines are likely to create early demand for sustainable synthetic hydrocarbon fuel (replacing crude oil derived Jet A-1) due to their need to transition towards net-zero emissions by 2050, but without a replacement propulsion technology. But by the mid-2040s DAC with geological storage (DACCS) has appeared and by 2050 is triple that for synthesis, with the two combined at over 500 million tonnes per annum. While the scale of DAC by 2050 is important at 500 million tonnes, this isn’t the technology that delivers NZE in 2050. It just isn’t big enough by then. NZE in 2050 comes through multiple other channels, with conventional CCS and land use change being the two big differentiators in a world that still uses considerable amounts of fossil fuel (albeit reduced by nearly two thirds from current levels).
Nevertheless, the scale up of CCS will be invaluable for DACCS, laying the groundwork by building the infrastructure for the transport and storage of CO2. At the moment, the focus is understandably on the capture side of DACCS, but it would be a major lost opportunity if the transport and storage infrastructure was not ready to take advantage of large scale DACCS when it does arrive.
Where DACCS has a major role to play is in the second half of the century. By 2100 this is an industry that has grown from nothing today to 6.6 billion tonnes of CO2 per year. In gas volume terms that’s like 2.2 billion tonnes of natural gas, which means that the CO2 gas handling infrastructure for DACCS in 2100 is getting towards the scale of global natural gas infrastructure today. From 2050 to 2100 the DACCS industry removes over 150 Gt of CO2 from the atmosphere, equivalent to 0.1°C of warming. This is an important contributor to the reduction in warming in Sky 2050 from 1.67°C (peak) to 1.22°C (in 2100).
And with 5.4 Gt of DACCS capacity in place, warming could conceivably be reduced by about another 0.15°C every 50 years after 2100. Direct air capture (and its combination with geological storage) is a technology for the longer term future, even though it will begin to bring more immediate benefits in the fuel synthesis industry in the shorter to medium term. But to build an industry that eventually handles CO2 on the scale we imagine in Sky 2050 by the end of this century, means starting now. While detractors have been quick to criticise DAC, in part because of a view that resources need to be focussed elsewhere today, fully addressing the climate issue means adopting a range of technologies and pursuing them relentlessly. The emissions problem we have is only partly solved by renewable energy, with the full solution coming when we can combine new energy sources with the management of CO2 from legacy energy sources. That is where DAC plays a critical role.
Note: Shell Scenarios are not predictions or expectations of what will happen, or what will probably happen. They are not expressions of Shell’s strategy, and they are not Shell’s business plan; they are one of the many inputs used by Shell to stretch thinking whilst making decisions. Read more in the Definitions and Cautionary note. Scenarios are informed by data, constructed using models and contain insights from leading experts in the relevant fields. Ultimately, for all readers, scenarios are intended as an aid to making better decisions. They stretch minds, broaden horizons and explore assumptions.