Using Offshore Wind Farms for Carbon Capture

The Biden administration has committed to greatly expanding the use of offshore wind power as part of its climate carbon reduction goals. Its aim is to generate 30 gigawatts of offshore wind energy annually by 2030.

To meet that target, the federal administration is expected to approve a huge number of offshore wind projects off the East Coast. It will also auction new wind energy leases in the Atlantic, Pacific and Gulf of Mexico.

One of the first large scale projects, Vineyard Wind 1, has already begun construction off the coast of Massachusetts.

When completed, the project will have a total of 62 wind turbines, cumulatively generating 800 megawatts of electricity annual (enough to power about 400,000 homes).

What if those offshore wind farms could be used to not only generate clean energy but also to remove C02 from the atmosphere?

David Goldberg, a Lamont Research Professor at Columbia University, is a marine geophysicist who is proposing just that.

He’s been exploring the potential of combining offshore wind turbines with carbon capture technology that could store C02 directly in rocks beneath the ocean surface.

“The fact that we’re already getting a huge wind farm infrastructure built offshore triggered me to think about the opportunities,” says David Goldberg. “There’s a lot of groundwork that has been done on regulations and permitting. There’s a lot of infrastructure that will be built and which could be used to power and stage storage projects”

He says that this approach would make sense from an investment perspective.

“You can start to leverage those investments by packaging the capture opportunity, the power opportunity, and the storage opportunity together. That reduces risk. It's a kind of ‘mutual fund approach’ from an energy company perspective,” he adds.

In this interview, Goldberg discusses how direct air capture systems could be integrated into offshore wind turbines and why he believes it’s a smart investment decision for the future.

Diana Davis, Oil and Gas IQ: You’ve been exploring the idea of pairing wind turbines with technology that captures carbon dioxide and stores it in the ocean. What is your research looking at?

David Goldberg, Marine Geophysicist at Columbia University: The geology of deep ocean rocks was my first area of interest and that drew me to the concept of deep ocean storage for C02. My research has taken me to look at these ocean rock formations, particularly basalt, as reservoirs for carbon.

Here’s how it works: you inject these rocks with captured C02, and it's stored permanently by a physical reservoir trap. It dissolves into water over time, and, as the dissolved C02 interacts with basalt rock, the carbon converts chemically into a solid, effectively turning CO2 into carbonate minerals. That makes it durable - to use the Department of Energy's description. You can have confidence that the carbon will stay there.

But I say would say that the idea of co-locating wind energy with capture and ocean storage is a question about motivation and opportunity: Can those assets being installed for wind energy be leveraged to co-locate with storage reservoirs?

All the technologies that are required exist; the research we need now is about how best to combine them.

For example, in Iceland a project called Carbfix has been capturing the carbon dioxide from a power plant and storing it in basalt rocks locally on land. They’ve also added a direct air capture (DAC) system from Climeworks, a Swiss technology company. Although this project is not yet storing CO2 in basalt below the ocean in Iceland, it’s a similar example of how these technologies may piggyback using nearby infrastructure.

There is more research that needs to be done to find sites where such systems could be deployed together. There’s also research that needs to be done on monitoring - especially offshore – to ensure that the carbon that gets injected stays put, and, in particular, to confirm how much carbon may convert into solid carbonates.

This concept of combining wind infrastructure, carbon capture, and storage, however, could be deployed in different places. The details of determining which technologies to use depends on where you are and what infrastructure is available.

The idea of installing co-located ocean carbon reservoirs on the US East Coast takes advantage of the significant offshore wind build out that is being planned and supported by the Biden administration. They are anticipating a build out that will generate 30 gigawatts of wind energy by 2030.

The fact that planning for a huge wind farm infrastructure triggered me to think about the offshore opportunities for storage that have already been studied. There’s a lot of groundwork that has been done, for instance, on geological characterization, regulations and permitting. There’s a lot of infrastructure that will be built and which could be used to power and stage storage projects. 

In addition, like Iceland, storage reservoirs exist near these sites so you can limit some long-distance transport issues [of captured carbon] from the equation.

From an investment standpoint, you can start to leverage those investments by packaging the capture opportunity, the power opportunity, and the storage opportunity together. That reduces risk. It's a kind of ‘mutual fund approach’ from an energy company perspective.

The practical aspects of it - aside from the investment and infrastructure opportunity - is the advantage that it brings for offshore operations, both for staging and for maintenance.

Fewer staging ports can be used for service vessels to manage equipment and personnel.

The same is true for the workforce – there are cross training opportunities to support a variety of equipment and operations may be managed jointly. Building up technical competency and support for offshore infrastructure is a big deal. Doing it in a coordinated and thoughtful way will help a lot.

Diana Davis, Oil and Gas IQ: You’ve also been working with the University of Victoria – not too far from where I live! You’re based in New York – what are you working on out on the West Coast?

David Goldberg, Marine Geophysicist at Columbia University: When you’re doing an injection for storage, you must demonstrate that carbon goes in and then stays put.

The University of Victoria has established infrastructure in place and understanding of the subsea geology; that location is one of the best studied sites in the world for sub ocean basalt.

Basalt is a unique reservoir from an energy company perspective and much of what we know about it comes from prior scientific studies at sites such as those on the West Coast.

Having that infrastructure and knowledge in place is a huge advantage, and that's why we started looking at the carbon storage potential through a previous study funded by the US Department of Energy, which has ended. A follow-on study, called the “Solid Carbon” project out of University of Victoria, continues to focus on capturing and storing CO2 in offshore basalt rock.

But there are distinctions between this site and the East Coast. The water depths are quite different in the two areas. Offshore windfarms, for example, can now be tethered in about 100 meters water depths; the ocean is quite a bit deeper at the West Coast site and would require floating turbines. That makes a big difference.

So, we have the advantage of good knowledge of the oceanic basalt formations on the West coast, but there are no immediate plans for a deep-water wind build out there. The East Coast build out is right in front of us.

On the East Coast, on the other hand, we're at an earlier stage in exploration and characterization of the basalt reservoir. We have the tools, especially with industry know-how, to increase this knowledge gap and prepare for pilot storage projects. We know how to move such projects forward – now we just need to do that.

Diana Davis, Oil and Gas IQ: How significant an impact could wind power and ocean storage make towards that goal of achieving Net Zero emissions?

David Goldberg, Marine Geophysicist at Columbia University: If we have electrons created by the wind, the best use of those electrons is to get them into the grid to replace fossil fuel-generated electrons.

However, that won’t be enough. We both need to both emit less CO2 and remove more of it from the atmosphere.

Capturing CO2 - whether it's from a power plant or from a direct air capture unit – requires storage. That gets us back to co-locating offshore infrastructure with nearby storage reservoirs.

There’s tremendous advantage to co-locating these storage reservoirs offshore with windfarms. We’re taking advantage of the size of the infrastructure that’s being built. Also, since these sites are offshore, they’re not right next to people and their property. That’s another significant advantage.

Also, the wind power has inherent inefficiency because it's intermittent. There are curtailments where the wind farm produces more energy than the grid can absorb. That energy could be captured and stored it in a battery, but battery storage doesn't yet exist at the longer time scales that are needed.

Converting wind energy to hydrogen may also be a viable pathway, but that adds another large infrastructure investment.

As an alternative, intermittent sources that curtail power could potentially use that power to capture CO2 using DAC – essentially using power that would otherwise be wasted to capture carbon and store it. While none of these things alone will be sufficient to realize Net Zero targets, together they can move us in the right direction.

Diana Davis, Oil and Gas IQ: How far from reality are we from realizing something like this?

David Goldberg, Marine Geophysicist at Columbia University: Direct air capture (DAC) is still at a very early stage. The largest currently active plant is in Iceland, and it captures 4000 tons a year, and uses a lot of local heat energy. It's not energy efficient yet. A handful of companies are trying to start up and scale up DAC to make the technology more efficient.

However, carbon capture from power plants, transport of storage pipelines, injection capabilities, and wind farms are all existing technologies that could be deployed tomorrow. The point is that implementing these together, where possible, is efficient and saves time and money down the road.

To some extent, this is now happening in Norway. They are looking at wind to power their offshore injection facilities. They're building out a project called the Langship Project that will capture CO2 at industrial plants on land, ship it to a hub port and then pipe it to an offshore site for injection and storage. This reservoir is not basalt rock but rather a more conventional reservoir.

Putting these pieces together will generate efficiencies and make a difference.

Another important aspect of this concept is offshore site monitoring. To monitor these activities, co-locating and combining sensors to observe environmentally sensitive areas makes a lot of sense. The networks, the power, and the information can be acquired in the same location.

Diana Davis, Oil and Gas IQ: What would you say if you had the CEO of a major energy company in the room to convince them that this approach is a smart investment decision?

David Goldberg, Marine Geophysicist at Columbia University: If they're picking up interest in any one of those three elements - carbon capture and storage or wind farms – they’re already planning to make huge investments. Why not leverage those investments by planning these climate-wise activities together?

This may offer advantages towards advancing a company towards Net Zero targets. Equally importantly, combining technologies may offer savings for the company. A hub approach to building infrastructure will save on the upfront costs for design. It saves on the geology and geophysics characterization work. It saves on the operational and maintenance costs. And it may save on the investment risk.

Additionally, the long timeline and regulatory efforts for permitting can be shortened. Acquiring permits for any one project alone is a significant time investment; coordinating potential prospect sites for multiple purposes in advance will speed things up.

The final thing I would say to a CEO is that there's so much to do and we are so far behind the curve as a global community. They should do anything and everything they can to reduce emissions and CO2 buildup in the atmosphere. We need all these tools because every ton of carbon counts.