1. Skip to content
  2. Skip to main menu
  3. Skip to more DW sites

Denmark wants your CO2, but why?

Jennifer Collins
September 6, 2024

If you can't beat CO2 pollution, then bury it? That's basically the thought behind carbon capture and storage. Denmark wants to become a leader in these efforts, and has the geological underground to lock away billions of tons of CO2. But locals ask, will it blow up in their face? An exploration of carbon capture technology.

https://p.dw.com/p/4kM5r

Interviewees:

Rikke Volf, visual artist and chairwoman of the local environmental association Havnso-Follenslev, Havnso, Denmark  

Tobias Sorensen, a senior analyst at CONCITO, a green think-tank in Copenhagen 

Jannik Kappel, senior technical project manager for carbon Capture, Amager Ressource Center, Copenhagen  

Charles Harvey,  professor of civil and environmental engineering, Massachusetts Institute of Technology 

Justus Andreas, managing director, Bellona Germany, a climate solutions think tank in Berlin  

Nina Skaarup, head of the geophysical department of the Geological Survey of Denmark and Greenland (GEUS)  

Listen and subscribe to Living Planet wherever you get your podcasts: https://pod.link/livingplanet Got a question for us? Email livingplanet@dw.com. And, if you like the show, leave us a rating and review on whichever podcast platform you use – and tell a friend!

Transcript:

Rikke Volf: This coming on top of it. No, that would just break me into pieces. I had to do something. I got really ... I'm, I'm angry. That's what I am.

How would you feel if you found out your home might become a dumping ground for Europe's CO2? 

That's exactly what visual artist Rikke Volf and others living in the quiet seaside town of Havnso on the Danish Island of Zealand found out in August 2022. 

Volf is part of a local environmental group in the maritime community, which is home to a small harbor lined with colorful boats and a bay perfect for swimming in summer. The area is dotted with charming one-story houses. Some are made of timber, others have white-washed walls and thatched roofs.

Volf and the members of the environmental group are worried what the plans mean for their idyllic home with its sandy beaches and dunes. 

Rikke Volf: We were told that it is very, very safe and we were told that it's a very well-tried, very well-proven technology everywhere in the world. There's a lot of places where it's going on and nobody's having problems with it.

Archived news footage: In February 2020, residents of this small town of Satartia, Mississippi were thrown into chaos and feared for their lives when exposed to an uncertain gas. Proponents of CO2 pipelines…

Rikke Volf: There's been accidents. We have realized there's been a huge accident over in Mississippi in 2020 in a small village where there were pipelines going through.

Archived news footage: From the moment the pipeline blew at 7:07pm and the moment people started passing out…

In 2020, a pipeline ruptured in Satartia a small village in Mississippi. CO2 spewed out from the pipeline. 

Archived news footage: My daughter was screaming and my grandbaby was on the floor screaming…

Residents described feeling a heavy pressure on their chests, not being able to breathe and passing out. 

Nobody died in the accident but around 45 people were treated in hospital and 300 people had to evacuate. 

This is exactly the kind of accident that Volf fears now that Havnso has become one of the Danish communities at the center of the tiny country's massive push to become a European CO2 hub. Denmark's push tie into larger European Union plans to use CCS to become climate neutral by 2050.

Under the plans, planet-heating CO2 will be captured at what are known as point sources. So directly from industry in Denmark and around Europe. It will then be transported to storage sites via pipelines, trucks and ships and injected into rock formations deep underground — the idea is forever. The whole process is called carbon capture and storage, or CCS for short. 

It's a controversial technology that's technically been around for a long time but has never really taken off, despite its seeming promise. Now it's a major part of not only European but also US plans to cut emissions. And it's imperative for reaching climate targets, say advocates.

Some experts, on the other hand, think it's a terrible and incredibly expensive idea that would lock-in a fossil-fuel based energy system and divert resources from other climate solutions like boosting battery storage and modernizing our electricity grids for green power. 

So in this episode of Living Planet we'll be looking at the pros and cons of CCS. I'm Neil King.

Rikke Volf: But then this CCS, the carbon capture storage thing, it really feels like a threat because I'm really in love with this place and the nature. 

Ten years ago, Rikke Volf bought and renovated a little one-story farmhouse in sleepy Havnso. It has white walls, a low roof, an atelier that was once an old chicken house where she paints and teaches art classes. And it has a garden bursting with fruit trees and flowers. And sometimes you also catch a glimpse of deer or hares on their daily walks... 

Rikke Volf: And they're eating my berry bushes, but I love them because I like them being here.

Volf wanted to escape the hustle and bustle of the capital Copenhagen, like many people who have moved to the rural area or have bought summer homes here. One reason was that she could better focus on her art.

Rikke Volf: But now it's much easier. I'm close to the stars, I'm close to the ocean, I'm close to nature, you know, everything. The inspiration is just around the corner all the time. And I feel connected with this place, and I just don't want anything ... I feel it's like violence really. I feel it's a violent thing that's going on here. I mean it’s just really not a very nice way to treat the citizens to say this is a big experiment and you're going to live on top of it. 

Carbon capture and storage like this has never been done on this large a scale before. So how did Denmark, a small country of 6 million people, decide it would ramp up the technology so rapidly and import CO2 from the likes of highly industrialized Germany? 

The first reason Denmark wants to do so is ...

Tobias Sorensen: Denmark has set a rather ambitious target in 2030 of reducing greenhouse gas emissions by 70% compared to 1990. And you have to bring all the tools out of the toolbox in order to get there. So in Denmark, we need CCS in some sectors that are hard-to-abate in order to achieve our climate targets.

That's Tobias Sorensen. He's a senior analyst with a focus on CCS at CONCITO, a green think tank in Copenhagen. That phrase "hard to abate" comes up a lot when talking about CCS. It basically means sectors that are difficult to electrify full right now, like steel manufacturing. Or they're hard to decarbonize because of something called process emissions. Cement is one example of this. Around half of its emissions come from a chemical reaction produced when making the building material's major components.

The second reason Denmark wants to build up a carbon capture and storage industry...

Tobias Sorensen: … has to do with the Danish geological underground. We have a well-suited underground for storing a lot of CO2, according to the initial surveys made by the Danish authorities.

Denmark wants to use CCS to achieve reductions of around 3 million tons of CO2 by 2030. But it could have capacity to store billions of tons of CO2 in former oil and gas wells currently in development in the North Sea and at underground sites onshore, according to geological surveys.  Denmark wants to bring huge storage capacity online both on and offshore in the coming decades. And that's expensive. Which brings us to another reason Denmark wants to ramp up CCS. 

Tobias Sorensen: If Denmark can import CO2, it will also be cheaper for Danish point sources to store CO2. We believe that we should take advantages of that for climate reasons and make storage available for countries that may not have it themselves or may lack public acceptance or just haven't started in time to make storage sites ready.

Denmark would have to emit for around 500 years to fill up its potential storage sites. So, it has plenty of extra space to help out its neighbors. That's good news for the European Union which has identified CCS as a key technology to reach its climate targets. 

But before Denmark and Europe can create a market for storing CO2, industry has to start capturing it. 

The Amager Bakke waste to energy plant in Copenhagen is demonstrating and testing how that can be done with a pilot CO2 capture project attached to the facility. Every day up to 300 trucks bring in municipal waste from the city. That waste is burned, generating heat and electricity for hundreds of thousands of homes nearby.

The facility rises up 85 meters. It also has a hiking area and artificial ski slope. It even has a climbing wall and a cafe at the very top with a view of the city. If you take the lift, you can peer into the plant and catch a glimpse of the waste management staff going about their work. 

The plan is to build up a large-scale carbon capture plant there after the demonstration phase that will start catching 500,000 tons of carbon each year. Although, it's unclear if and when construction will begin, that would reduce the waste facility's CO2 footprint by 95%, which it says is like replacing 250,000 petrol cars with electric ones on Danish roads. 

But capturing carbon is not a matter of sticking a filter on a chimney and sucking out the greenhouse gas. 

It's a complicated process with a few different steps, explains Jannik Kappel, who is the chief consultant for carbon capture at the facility, as he points to some large metal towers. It's very noisy in the plant, so we've paraphrased what Kappel says. 

So basically, the first step is to clean the flue gas emitted during waste incineration to make sure there are no pollutants in it. 

That then flows into something called an absorber, which is kind of shaped like a tower. The gas is fed in from the bottom, so it rises up. And then a liquid solvent called amine is dropped in from the above. Most of the CO2 binds to the amine liquid. 

The next stop for the CO2-amine liquid is another tower a so-called desorber. This part uses a lot of energy. Here, the liquid is heated to around 105 degrees Celsius, or 221 Fahrenheit, and releases the CO2. It's kind of like the way your soda goes flat when it gets warm. 

The CO2 is collected, cooled, compressed and can then be transported. And the amine liquid goes back into the system to be reused. 

There are several ways to capture CO2 and a lot of research into new technology. But right now, amine-based solvents are considered the most scalable and commercially viable method. And this is where three criticisms of carbon capture come in. 

Firstly, waste solvent left over from the capture process may pose a risk to humans and the environment, more study is needed. The solvent can be reused a number of times before it degrades but there is no good way to dispose of it. Kappel says they are investigating whether it can be burned as waste. 

The second criticism of the carbon capturing process is that it requires a lot of energy and that means it's also expensive to do. 

Experts say it makes sense to use carbon capture at a facility like Amager Bakke. That's because the heat generated during the process could be piped into the district heating system and that makes up for some of the energy used to catch the CO2. 

But experts also say it makes zero sense to use CCS at a fossil-fired power plant. It's more efficient to just build a solar or wind park.

And that's because when you add carbon capture, the plant needs to spend a chunk of the energy it produces to grab the CO2 from its smoke and store it safely. So, let’s say CCS happens on a coal plant, for instance:

Charles Harvey: You would reduce the power output from a coal plant if you were to try and stick carbon capture and sequestration on it, or if you wanted to keep the same electricity production, you'd have to burn that much more coal.

That's Charles Harvey, he's a professor at MIT in the US and a CCS critic. But he wasn't always a critic. He got into the carbon capture business about 20 years ago because he wanted to do something that combines hydrogeology with climate research.

Charles Harvey: So, I thought this was an area where I could contribute and frankly, there was a lot of research money in it because the oil companies, particularly at prestigious universities, were and still are very interested in funding research on this.

Back then he worked with an ambitious postdoctoral researcher who decided to start a CCS company and raised a large amount of money.

Charles Harvey: But then we kind of all realized that our elevator pitch failed, was beginning to fail. And the reason is that the cost of renewable energy was dropping so fast that there wasn't anywhere that we could find where it made sense to do carbon capture and sequestration, rather than just replace power generation or whatever industrial process was producing the CO2 by some electrified version.

It just doesn't make financial sense, particularly for power plants, says Harvey. And the third big criticism of current capture technology is... 

Charles Harvey: You never capture all of the carbon dioxide. So, the proposals for things often have something, you know, 90% capture. What we know in practice is it's 75% or something like that.

One Stanford study found capture rates for one coal power plant was actually at around 11% if you take in the emissions for the lifetime of the fuel, from mining to transportation, for instance. 

The next building block in the CCS market is transport from capture plants to storage locations offshore under the sea in depleted oil and gas wells and deep underground onshore. Denmark and Europe are getting ports and transport companies on board to make trucks and ships ready to carry CO2. 

Ultimately, though, Europe will need a CO2 pipeline network of around 19,000 kilometers by 2050 — like a smaller version of the continent's gas network. Those pipes will connect capture facilities to CO2 storage hubs like Denmark. 

Back in the village of Havnso, it's something that worries Volf and others. 

Rikke Volf: Out here, it's an area with a lot of small villages and small roads. Small villages connected by small roads, and it's not built for a lot of heavy traffic. The long-term plan is to make it run in pipelines. I don't know so much about it, nobody does really, but I mean any pipeline can break. So, I'd be concerned about that but also what it does to the whole area.

The Danish government and other proponents say any CCS infrastructure in Europe will be done safely and will be strictly regulated, including the pipelines.

Justus Andreas: Everyone has, of course, the right to be concerned whatever they're doing. You have a right to be concerned if there's a hydrogen pipeline passing your village. Those are technical, human made infrastructures.

That's Justus Andreas. He's managing director of the Germany office of the Bellona Foundation, a climate think tank that helped get CCS off the ground in Norway. He's now tasked with reviving the CCS debate in Europe's industrial powerhouse. And while he believes people have the right to be concerned, Andreas adds that the risk from CCS is small and manageable. 

Justus Andreas: … because they are not in a sense insurmountable risk. These are technical risks. These are mechanical risks. No one cares about the fossil gas network that we have, even though we have explosions every once in a while in a house. That has not started a huge movement to say we don't want gas boilers anymore because we've accepted that tiny risk that comes with it as manageable, as acceptable.

US research found accident rates for Co2 pipelines were similar to those carrying oil and gas. And that they're rare. But big ruptures when they happen, could be extremely dangerous, especially if you are in the "kill zone" around a CO2 pipeline. 

That's because CO2 is heavier than air, so it displaces oxygen, including in your lungs. 

Charles Harvey: And you essentially drowned. This happened in Mississippi a number of years ago with a pipeline. And it's a pretty terrifying thing because one thing that happens is that you know the ambulances and the fire trucks try and get there, but their engines all turn off because there's not enough oxygen in the air to run.

That's the Mississippi pipeline accident Volf referred to earlier in the episode.

Archived news footage: I said, we ain’t gonna make it. That was the last words I said to 911.

A landslide caused the rupture and now the US government is looking into tighter rules for pipelines. 

But even if the capture and transport parts are up, running, and fully regulated, the last piece in the CCS puzzle needs to be in place. And that's the storage part. 

Justus Andreas: The real question is when we inject it because CCS is only as good as its storage site. It's only as good as the permanence of avoiding the CO2 reaching the atmosphere or removing it from the atmosphere. And so, it's really important that the storage sites hold.

So, what makes for a good storage site to permanently sequester CO2 and how do you find it? Well, it turns out in Denmark, that's the job for the state geologist. Yes, Denmark has a state geologist.

Nina Skaarup: My name is Nina Skaarup. I'm a head of the geophysical department of the geological survey of Denmark and Greenland, also called GEUS for short. In Danish, it's called a state geologist.

Skaarup has been at GEUS for nearly 30 years but like any good geologist her fascination with rocks goes back to childhood.

Nina Skaarup: I have always been interested in rocks and fossils, but not knowing at my childhood that it was something you could be for living. It was just some fun I had with my parents. So, every holiday we had been on the beach and the cliffs and looking for treasures. So it has been a really big part of my childhood. I do remember finding quite big ammonites in Sweden.

Skaarup still searches for fossils and they're all over her house and garden, she says. But alongside fossil hunting, she now also investigates the best places to put the CO2 that was trapped under the ground in the form of fossil fuels like oil, gas and coal for millions of years. And part of that involves going out into communities and doing seismic investigations.

Nina Skaarup: We are just moving on the roads with these trucks and putting sound waves down. So, you are inducing a shake of the underground, and then you have microphones along the road or on your field that will collect these sound waves. They will be reflected by the different geological layers. So, when they hit the first layer some of the pulses will go up and be recorded. But some of them will continue down to the next layer and the next layer and the next layer. And then it comes up and makes a picture of the underground.

Usually, locals come over to find out what they are doing or ask them about how CO2 storage works, and if it will be harmful for things like the water supply. 

Nina Skaarup: So, we really like that kind of question because it's no, there will be no harm to the groundwater from this. The groundwater in Denmark is normally between 50 and 100 meters. And this CO2 storage site, it will be at least at 800 meters and in absolutely most places in one and a half kilometers depth. So, it's really extremely separated.   So that's very good questions. You can get the fear away from them in a moment.

Some questions are a bit more, ah, unconventional…

Nina Skaarup: When we were going out there and collecting seismic data where we are doing this bit of shaking of the underground, we had a farmer coming and asking us if his dairy cows were in any danger or might not producing some milk. 

And absolutely, that was one of the questions we hadn't expected. 

They told them they didn't know for sure, but it was unlikely. 

Nina Skaarup: In fact, he came back and told us that that you're right. It has absolutely no effect. The producing of milk was absolutely the same despite we were there. So that was quite fun.

But anyway, when Skaarup is not answering questions about dairy cows, she's busy sending pulses in the ground and looking for …

Nina Skaarup: A sand layer with lots of porosity, which is pore spaces between the individual grains of sand and then overlaying by thick, tight layer of clay and then at the right depth.

Basically, when the CO2 is injected into the sand layer, which has to be at least 800 meters deep, it becomes a liquid, which is...

Nina Skaarup: … normal behavior of a gas. The sand layer, it can soak up the CO2 and the clay layer will prevent it from escaping and be above as a seal or roof on the sand.

Essentially the CO2 very slowly mixes with salt water in the sandstone, and floats to the top of the underground storage structure, which Skaarup describes as looking like an upside-down bowl. And in that bowl, the CO2 should stay, permanently and safely. Geologists can also monitor where the gas is.

Danish authorities say an area will only be chosen if it is truly suitable and safe for storing CO2. Then companies largely in the oil and gas business will develop the site and begin injecting. In Havnso, Norway's state energy company Equinor, formerly Statoil, has the storage exploration permit. Those companies will have to monitor the site for potential leaks and make sure the CO2 isn't moving in odd ways, or that pressure isn't building too much so they can head off any problems at a very early stage. 

Justus Andreas: The operators of the storage site will know where the CO2 is moved and if it moves into an area where they see the risk of a leakage no matter how big or small they need to respond to that. Sometimes it's about closing up old oil and gas wells that have not been closed properly where we see a little seepage of CO2 and sometimes it's realizing well the geology doesn't allow for this much injection and we need to reduce the injection rate to keep the pressure well below the dangerous zone.  

That's Justus Andreas from Bellona again. And the thing is that the companies won't know that the site works until they actually start injecting. Right now, the country's 22 billion tons in storage capacity is theoretical. 

Justus Andreas:  Scientists having gone underground, not quite, but having looked underground and figured out this site could work, this site could work, this fulfils the requirements. You don't know until you properly inject. You have all your models. So, if you begin having storage sites clustered in the North Sea and you begin injecting, it could very well be that the potential is much lower than we thought. It’s the same thing when you think there’s a lot of oil or gas under the ground and voila, it’s not that much. And this is the expertise, of course, also of the oil and gas industry, which is why they're involved in CCS as well.

At the moment, very little CO2 is stored underground in Europe.

Under a binding target, the EU wants to make 50 million tons of CO2 storage available by 2030. That figure could grow to 450 mega tons by mid-century. That's around what a country like Brazil emits in one year. Oil and gas companies operating in the EU will have to contribute to those targets. The idea is to put pressure on companies like Shell and ExxonMobil to deliver on a technology they have been saying has been ready for years and can help to reduce emissions. 

Carbon storage has been used for years on a small-scale. But the problem is that, particularly in the United States, it is used to do something called enhanced oil and gas recovery. Nearly all of the 15 CCS facilities operating in the country in 2023 captured CO2 from natural gas and injected it back to push up oil or gas that otherwise couldn't be reached. It's even being supported with government climate subsidies. That CO2 is considered stored even though it...

Charles Harvey: It was already underground, but you brought it up and separated it and captured it and then and then you're putting it back in. And sometimes this is called this is one of the hard-to-decarbonize industries is natural gas processing. But the easy way to decarbonize this is just to leave it underground. There's no, you know, expensive technological fix that we need to invest in for that.

That’s Charles Harvey again. The fear is that CCS could be used in other parts of the world for enhanced oil recovery under the guise of a climate solution. In Europe, there are no plans to do enhanced oil recovery with CCS and the EU says it is excluded from the bloc's CO2 storage target. 

But this does get to a fundamental question about if and when CCS should be used. 

Critics like Harvey say CCS is just a pipedream, a distraction from real climate action.

Charles Harvey: I think it's the last gasp of the fossil fuel industry. It's the last gasp that could last a long time.

Harvey says our resources and time are limited so we should focus all our resources on expanding renewables, modernizing electricity grid, improving battery storage for green power and building interconnectors so we can send electricity from the sun and wind across borders. 

He argues that the savings from CCS are so small that we can just wait for new technologies or alternatives for the hard-to-abate sectors.  

Charles Harvey: Building CCS is so slow and expensive that it’s not an alternative.

Advocates like Justus Andreas think it's one tool in our arsenal to slow climate change.  However, his organization Bellona believes it should ideally only be used when the alternatives for decarbonizing are limited and it's not going to lock in fossil fuel use. And it shouldn't be used for coal and other fossil fuel power plants in Europe, at least. For him, it might be expensive but the cost of not doing it is too great.

Justus Andreas: I think this fallacy that you can play off one solution with another, I think we need to go down all the tracks and as we go down the tracks, one will maybe fall away gradually and if that is CCS, great. But in the meantime we've prevented millions of tons of CO2 from ever reaching the atmosphere and that is couple of decimal points of temperature over the next decades and that can decide over whether cities are underwater or not, over how many houses and people die in bushfires and forest fires.

Back in Hanvso, Rikke Volf remains unconvinced that carbon storage should be done at all and believes we should be fully focused on other solutions. And she also doesn't feel safe about potentially living on top of a CO2 storage site even with reassurances it can be done safely and will be monitored.

Rikke Volf: But what does it help us that they monitor? I mean, if there is an accident, it's an accident, right?

Volf doesn’t trust the fossil fuel companies who are promoting CCS as a climate solution. For her it's like the wolf guarding the sheep.

Rikke Volf: They try to save the climate crisis by a technology that is in favor of the oil companies. And as soon as there's so much money involved in a project, I just don't think it's anymore about saving the climate. It's something else going here and it makes me really nervous, and it makes me feel like I'm taken hostage in this.

Volf and the local environmental groups will continue to oppose any moves to make their community a burial ground for CO2 and they are looking at legal avenues to stop the plans. In the meantime, she continues to find artistic inspiration from the nature around her.

This week's episode of Living Planet was produced and researched by Jennifer Collins. It was co-produced and edited by me, Neil King. Our sound engineer was Jan Winkelmann. If you have any questions or feedback, please do write us or send us a voice message to livingplanet@dw.com. Living Planet is brought to you by DW in Bonn, Germany.

Skip next section About the show

About the show

Living Planet 210318 Podcast Picture Teaser

Living Planet

Looking to reconnect with nature? Want to make better decisions for the health of the planet? Every Friday, Living Planet brings you the stories, facts and debates on the key environmental issues of our time.