Direct Air Capture vs Point Source
Is Direct Air Capture a Better Alternative to Point Source Carbon Capture and Storage?
When discussing carbon capture technologies, the two main approaches that come to the forefront are point source carbon capture and storage (CCS) and Direct Air Capture (DAC).
In large industries, the focus has mainly been on point source carbon capture since this is an area of interest for the oil and gas industry who are looking for ways to reduce their emissions. While both technologies aim to tackle carbon emissions, DAC emerges as a more elegant solution. Let’s explore why.
Understanding Carbon Capture and Storage
Point Source CCS works by capturing carbon at the point of emission—usually at industrial facilities like power plants, cement factories, or other large-scale polluters. The CO₂ is captured on-site and then transported, often through pipelines, to storage locations where it can be sequestered underground or utilised elsewhere.
The challenges facing carbon capture and storage at point source
Transporting the CO₂ safely to sequestration sites
At first glance, point source capture seems like a logical approach: capture carbon where it’s produced. But there are some significant challenges, especially with transporting the captured carbon. Moving CO₂ requires building extensive pipelines, which is no small feat.
Moreover, there’s a lot of resistance from communities about pipelines running through their areas, not to mention the logistical hurdles of obtaining permits and ensuring safety standards across different regions.
CO₂ quality issues
Another issue with CCS is that when multiple emitters use a single pipeline, you have to ensure that the carbon being transported meets strict quality controls. If there’s any variance, it can lead to safety risks, making the process more complex and, quite frankly, a bit clumsy.
The Simplicity of Direct Air Capture
DAC parks can be located next to sequestration sites: no long-distance transportation needed
Direct Air Capture, on the other hand, offers a much more refined process. With DAC, carbon is captured directly from the ambient air, rather than being tied to a specific industrial site. And here’s the key advantage: DAC plants can be placed right next to where the carbon will be stored – no need for long, controversial pipelines snaking through towns or cities.
For more detail, see: What is Direct Air Capture? and How Does Direct Air Capture of Work?
Imagine this: a DAC facility sits next to a geological formation where carbon can be mineralised, or near a port where CO₂ can be loaded onto ships for offshore storage. The captured carbon is handled on-site, eliminating the need for risky transportation. This makes DAC both less complicated and safer.
Cost of Direct Air Capture vs point source CCS
Yes, the cost of capturing CO₂ from DAC is currently higher than from point sources, but when you factor in the massive cost and difficulty of transporting CO₂ for CCS, the gap in expense starts to narrow. And, as DAC technologies evolve, it’s likely that this cost difference will shrink even further.
Environmental Advantages of Direct Air Capture vs Carbon Capture and Storage
DAC has location flexibility
The geological formations suitable for CO₂ storage are often in remote areas, far from populated regions. By setting up DAC plants in these isolated spots, you avoid any impact on urban or suburban landscapes.
DAC can use off-grid renewable energy sources
What’s more, these remote DAC sites can be powered by off-grid renewable energy—solar and wind farms that don’t need to be connected to the national grid.
This is an important point because there’s currently a lot of pressure on grid capacity. Many renewable projects struggle with getting grid connections, which can delay or limit their deployment. But if you don’t need to connect to the grid, that challenge disappears entirely.
By using off-grid power for DAC parks, we can build more renewable energy infrastructure in remote areas, all without affecting the energy demands of the grid. This approach not only makes DAC more sustainable, but it also opens up new opportunities for renewable energy development in places where it was previously unfeasible.
Comparison Table Between Carbon Capture and Storage and Direct Air Capture
| Direct Air Capture (DAC) | Carbon Capture and Storage (CCS) | |
| Definition | A process of capturing CO₂ directly from the atmosphere | Captures CO₂ from large point sources, like power plants or factories |
| CO₂ Concentration | Very low concentration (approx. 0.04%) | Higher concentration (up to 15% from fossil fuel plants) |
| Technology Maturity | Emerging, with some pilot and operational plants | More developed and already used in industrial applications |
| Energy Requirement | High energy demand: aims to use off-grid renewable energy | Lower energy demand compared to DAC, as CO₂ is more concentrated |
| Cost | Typically higher due to energy intensity and newer technology | Generally lower, though still costly, especially for transport and storage |
| Infrastructure Needs | Requires energy and infrastructure for air capture | Requires pipelines for transporting captured CO₂ to storage sites |
| Location & Scalability | Can be scaled independently of emission sources | Limited by proximity to large point sources and storage sites |
| CO₂ Storage | Often paired on site with storage (e.g., mineralisation) or utiliaztion | CO₂ is transported and stored underground |
| Focus | Removes historical emissions and addresses diffuse sources of CO₂ | Reduces emissions from ongoing industrial processes |
Basically, DAC removes the CO₂ already in the atmosphere while CCS prevents more CO₂ from being added.
The two technologies differ in approach and application – DAC envisions large-scale projects whereas CCS is built as part of an existing industry. In the end, both solutions can be used as part of the whole multi-pronged approach to target emissions, along with reducing emission and using other carbon dioxide removal methods.
Additionally, DAC has the advantage of being easy to measure, which makes it attractive to industries with hard to abate emissions like aviation and shipping who want to account for their carbon credits.
Big Oil’s Focus on Point Source CCS
Despite DAC’s potential, it’s clear that most of the big money in the carbon capture space is currently going into point source CCS. Why?
The oil and gas industries are heavily invested in point source technologies because they need to comply with emissions regulations. Capturing emissions at the point of production is a way for these industries to demonstrate that they’re taking steps toward sustainability, even if it’s primarily about meeting legal requirements.
Because of this, the big oil companies—and the service providers that support them—are pouring significant resources into CCS. This explains why point source solutions get more attention and funding, even though DAC may ultimately offer a cleaner and more elegant solution.
DAC: A Growing Industry with a Promising Future
Direct Air Capture is still in its infancy. It doesn’t yet have the kind of backing that point source CCS does, and its advocates are relatively quiet by comparison. But that’s starting to change. As the economic case for DAC strengthens and its environmental benefits become clearer, the industry is beginning to find its voice.
It’s essential that DAC gets the attention it deserves as the potential for DAC to help mitigate climate change is enormous. By capturing carbon from the air, avoiding the need for massive infrastructure projects, and using off-grid renewable energy, DAC could play an important role in reducing global carbon emissions.
Conclusion
In the debate between point source CCS and Direct Air Capture, DAC offers a more refined, efficient, and ultimately more environmentally sound solution. While point source has the backing of big industries, DAC is quietly showing itself to be a smarter, more sustainable option.
As the technology advances and costs come down, we’ll likely see DAC playing an increasingly important role in the fight against climate change. Now’s the time to make sure this solution gets the attention and support it deserves.
For more, see:
Benefits of Direct Air Capture
What is Carbon Sequestration?
Hard to Abate Industries and the Decarbonisation Challenge