It is no secret that direct air capture (DAC) technology is, at present, an energy-hungry one. It simply requires a lot of energy to recover a meaningful volume of CO₂ from the air, when its concentration is so dilute (about 0.04% of the atmosphere). Solving this energy requirement lies at the heart of making DAC affordable and scalable.
To make any sense from a climate impact perspective, DAC’s energy source needs to be low-carbon, meaning that its fate is inherently tied to that of renewable energy. To scale DAC, we will simply need an abundance of cheap and readily available green energy.
Until the world’s energy infrastructure can deliver that, there are justified concerns that deploying DAC today could divert clean energy from where it is needed most — namely, to electrify technologies which currently depend on fossil-based power.
There is a solution to this dilemma and it lies in making DAC’s energy requirement an opportunity for renewable energy developers. Here’s how we at Mission Zero are intentionally designing our electrochemical direct air capture technology to complement — instead of compete for — renewable energy.
Rewarding vs disincentivising renewable energy production
The green energy revolution is well underway, with the past decade witnessing a vast expansion in the capacity and deployment of intermittent renewable energy systems — mainly, in wind and solar. Expanding it further requires renewable energy developers to make returns on their initial capital investments. Yet, to this day, the cost of building out renewable infrastructure is still too high.
While low renewable energy prices are great for consumers, they make it hard for developers to make their initial investments profitable, especially when prices become negative and consumers are paid to use renewable energy. As more renewable energy projects are connected to electricity grids — pushing clean energy availability up and prices lower — this trend will only increase. This mix of high costs and low energy sale returns is already creating an environment where renewable energy developers like Statkraft are now reducing their growth forecasts.
Source: ICIS via The Financial Times
Typically, governments try to incentivise companies to build renewable energy projects by paying for their curtailed energy — the amount of green energy that goes unused when renewable energy generation outstrips the amount of energy that electric grids require to fulfil demand. Yet, this approach essentially pays companies to not produce renewable energy.
Policy Exchange, a climate focused think tank, estimates that the UK is losing £1bn pounds a year — increasing to £3.5bn annually in the 2030s — because of energy system constraints. In addition to creating perverse market incentives, this approach will clearly not be sustainable for public finances as more renewable energy projects become operational.
Clearly, we need to rethink this approach to one that incentivises the continued expansion of cheap renewable energy without using taxpayer money, while also reducing the huge wastage of green electricity currently involved in balancing the power grid. This is exactly where electric-only direct air capture technology offers wind and solar developers an exciting opportunity.
Designing DAC for intermittency and co-location
By designing early direct air capture technology to thrive on intermittency and co-locate easily with renewable infrastructure, our young industry can generate climate and economic value for renewable projects. Developers can feed surplus renewable energy that cannot be fed into the grid to power the recovery of CO₂ from the atmosphere. The same logic can also be applied to monetise energy generated by renewables awaiting grid connection, which in the UK alone is on average a five-year wait.
Source: NREL. Standard Scenarios 2020
While battery storage is an important part of solving renewables curtailment, it is only useful when there is a limited variation in renewable energy generation. It is ideal, for example, for solar farms in Australia, but of limited value to wind farms in the North Sea, where there is much greater output variation. This makes using that surplus green energy at the point of production a much preferable option.
Connecting intermittent processes like DAC to harness surplus energy when it is generated offers renewables developers massive savings. It provides a revenue stream for energy that grid consumers are unable to use — or that is practically unable to ever reach them — which serves to increase the profitability of both existing and stranded new renewable infrastructure.
It also offers one of the cheapest pathways for stripping carbon from the atmosphere, as energy generated directly from a renewable asset at peak production is among the cheapest in the world — free from the added costs of battery storage or inverting the power into AC required by the grid. Lower the cost of doing DAC, and you increase the return of this revenue stream.
The answer is electrochemical
At Mission Zero, we have intentionally designed our electrochemical DAC technology to use green energy responsibly and work in step with the build-out of critical new renewable infrastructure.
Our plug-and-play electrified systems can be easily co-located with different renewable sources — whether on or off grid — and output can be flexibly adjusted in seconds to make best use of variable loads. Simply put, they thrive on intermittency, allowing operators to increase atmospheric CO₂ recovery during periods when renewable energy is most abundant and at its cheapest, and decrease production when it is scarce.
When using curtailed energy, there’s simply no reason not to double or even triple the output of our system relative to its normal base rate of CO₂ output under regular conditions. This production flexibility is crucial for subsequent use or storage of that CO₂, where downstream processes often need to run continuously for production cost and maintenance considerations.
For many other DAC approaches, and indeed chemical processes in general, the twin considerations of energy and output consistency sandwiching the technology are often treated as technical and economic hindrances, but at Mission Zero, we see them as opportunities for better fulfilling the market’s needs.
All of which underlines our thinking that in a world where the price, availability, and demand for green energy is highly variable, DAC solutions must be built to offer energy flexibility as standard.
