Carbon capture and storage

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How it works

Achieving net carbon removal

Our biogenic CO2 sources

FAQs

According to the Intergovernmental Panel on Climate Change, we’ll have to remove up to 10 billion tonnes of CO₂ per year by 2050 if we are to reach net-zero globally. At Ørsted, from end 2025 we’ll capture 430,000 tonnes of CO₂ from two of our heat and power plants and store it in the North Sea.

How do we capture carbon, transport it, and store it under the sea?

1. Capturing and liquefying the CO₂

We’ll use carbon capture units supplied by Aker Carbon Capture to:

capture around 280,000 tonnes of CO₂ per year at our woodchip-fired Asnæs Power Station in Kalundborg

Plan of Asnæs Power Station including carbon capture area

capture around 150,000 tonnes of CO₂ per year at our straw-fired Avedøre Power Station in Greater Copenhagen.

Plan of Avedøre Power Station including carbon capture area

The capture units absorb the CO₂ with amine solvents, separating it from the flue gas from the heat and power plant. The CO₂ is then purified, compressed, and liquefied ready for transport.

2. Shipping the CO₂ to Norway

We’ll transport the CO₂ captured from Avedøre Power Station in Greater Copenhagen to Asnæs Power Station in Kalundborg – by truck, until we have a pipeline across Zealand.

Our partner Northern Lights will then ship the CO₂ from Kalundborg to their onshore terminal in Øygarden, Norway.

Asnæs Power Station will serve not only as a hub for shipping our CO₂, but potentially also for shipping other emitters' CO₂. This is why we’ve called the carbon capture area of the plant Ørsted Kalundborg CO₂ Hub.

Map of where carbon will be captured, transported and stored

3. Storing the CO₂ in the North Sea

From the Northern Lights onshore storage facilities in Øygarden, Norway, the CO₂ will be pumped through a subsea pipeline to the Aurora storage complex around 100 km offshore. The CO₂ will be injected into the storage complex, which is a 2.6 km deep saline aquifer.

The aquifer has two primary storage units (sand reservoirs) and an overlaying sealing layer (cap rock) that ensures the CO₂ containment. The sand reservoirs have pore space between a rock framework, and this porous space is currently filled with brine (saline water).

The CO₂ will displace the brine and stay trapped in the porous space, where a small portion will mineralise, some of it will dissolve in the brine, and most of it will be permanently structurally trapped.

4. Certified carbon removal

Our carbon removals are certified by an independent third party under the VERRA standard.

Microsoft has agreed to purchase 2.67 million tonnes of certified CO₂ removal over 11 years from us. This will help Microsoft meet their climate commitments.

The Danish Energy Agency has awarded us a 20-year subsidy contract for Ørsted Kalundborg CO₂ Hub. The hub will help achieve the Danish climate targets for 2025 and 2030.

The project shows that when operators, technology providers, offtakers, and policy makers work together, we can reduce the cost and time to market of decarbonisation solutions.

Prefer to see the process in a video?

How do we achieve net carbon removal?

Our heat and power plants use biomass such as straw or wood chips to provide heat and electricity to Danish households.

Bioenergy is renewable as the biomass is from sustainably managed forests or agricultural areas that produce wood products or agricultural commodities for society. We use their waste and residues instead of fossil fuels at our heat and power plants.

The forests we take residues from are replanted and are growing. This means the amount of CO₂ stored in the residues we take is matched by the CO₂ taken up by new trees during growth.

As we also capture and permanently store the CO₂ emitted when burning the residues, the net amount of CO₂ in the air is lower than before.

The carbon removal process in a simple infographic

About our biogenic CO₂ sources – straw and wood chips

Straw – a waste product from Danish farmers

The straw-fired unit at Avedøre Power Station converts straw into electricity and district heating.

Straw is a residue from production of cereals for food or feed
Straw is often in excess because farmers can’t use it for other purposes – before the 1990s, it was often burnt onsite
All straw is sourced locally.

Wood chips – using up leftover wood

Asnæs Power Station uses woodchips to supply Kalundborg and the local industry with process steam, heat, and electricity.

Main source is forest management: Logging and thinning residues, tops and branches, low-grade roundwood
Small amounts are from non-forest areas: Park and landscape waste, agricultural woody biomass
Wood chips come by truck from Denmark or by ship from countries around the Baltic Sea.

Our partners

Find out more about Aker Carbon Capture and Northern Lights, and about Microsoft’s carbon removal programme.

Frequently asked questions about carbon capture and storage (CCS)

What is a carbon hub?
A carbon hub is a hub for captured carbon from different emitters that will be transported for storage or utilisation. A carbon hub offers a combination of port facilities, heat offtake, access to existing energy infrastructure, and zones for industrial activities. Thus, a carbon hub is ideal for both CCS and CCU activities.

At Asnæs combined heat and power plant (CHP plant) we'll capture our own carbon and also ship from there, and we'll be able to help others handling and shipping their carbon.

We have the experience in capturing carbon, and we have the facilities to create Denmark's first carbon hub.
Why don’t you use the Danish storage facilities and support the creation of a new Danish industry?
To meet the tender criteria, we had to be sure that the storage facilities would be ready in 2025 already. The Northern Lights project will be completed in 2024 and is the most mature carbon storage site in the North Sea.

We have of course been in dialogue with Danish storage operators as well, and our choice of storage operator for this project won’t exclude other operators for future projects.

Licenses for onshore storage of carbon in Denmark won’t be awarded until 2024, which further proves that this wasn’t an option for this tender.
How much carbon is emitted during the handling and transportation of the carbon?
According to the current estimates for the project, there’s a total emission in the project value chain of approx. 23,000 tonnes per year, which corresponds to approx. 5 % of the collected 430,000 tonnes of carbon. This includes transport of carbon by truck and ship as well as emissions in connection with transport of fuel to the plants.

Transport of carbon by truck and ship will account for about 2.7 %, while the rest is emissions from handling and transport of fuel to the plants as well as consumption of materials for the structures, etc.
How can it make sense to transport the carbon by truck from Avedøre to Asnæs?
Avedøre Power Station will capture approx. 150,000 tonnes of carbon per year, which will initially be transported by truck. The current estimates are that truck transport of the 150,000 tonnes of carbon will have an annual emission of approx. 900 tonnes of carbon, which corresponds to approx. 0.6 % of the 150,000 tonnes of carbon transported from Avedøre Power Station to Asnæs Power Station.

Transport by truck is less harmful to the environment than the alternative, which would be freight by ship between the two power plants. In addition, the solution with truck transport provides greater flexibility – both in relation to the possibility of transport by electric trucks and to the flexibility for a possible switch to pipes.

We’re working with relevant stakeholders to identify and develop efficient carbon transport solutions, including shared infrastructure such as pipelines.
Several experts are wary of carbon capture on biomass, as this could extend the lifetime of CHPs that are being phased out. Don't they have a point?
Our carbon capture plans will not impact the lifetime of our biomass plants. The lifetime of our plants depends on the demand for district heating, power, and ancillary services.

Biomass consumption in Denmark will decrease in line with the increasing electrification of heat generation. According to the Danish Energy Agency, Denmark will, however, continue to need a certain amount of sustainable biomass – in combination with heat pumps, electric boilers, and Power-to-X plants – to maintain a high level of reliability of supply.

For those plants that have a long lifetime, it makes perfect sense to capture the carbon and either store it or use it for producing green fuels, as there’ll be a demand for biogenic carbon.
Wouldn’t it make more sense to use the carbon for producing green fuels instead of storing it in the ground?
These aren’t mutually exclusive. We still see considerable opportunities in utilising the biogenic carbon from our CHP plants to PtX.

CCS is a stepping stone for PtX based on biogenic carbon, as we’ll be able to utilise several parts of the CCS value chain for the PtX value chain.

We see CCS as a flexible option for storing biogenic carbon and delivering negative emissions while building PtX opportunities.
Do Ørsted’s carbon capture and storage projects lead to actual climate change mitigation?
Yes they do.

With Ørsted’s strict criteria for use of certified sustainable biomass, capturing and storing the biogenic carbon will deliver real and quantifiable mitigation of carbon. Through cooperation with recognised institutions, our carbon removals will be certified according to international carbon removal standards to ensure high integrity and transparency.

Beyond the requirements of the certification scheme, Ørsted is taking extra precautions through internal due diligence, screening of off-takers, and specific use restrictions to protect the certificates against use for other purposes than climate mitigation.

We acknowledge that using certificates for offsetting can only be a complementary tool to substantial emission reductions. The use of carbon removal certificates should comply with the mitigation hierarchy and only be used for residual emissions after other climate action.
Are Ørsted’s carbon capture projects additional – i.e. would they have been implemented in the absence of the generation and sale of carbon removal certificates?
Yes, our CCS projects are additional.

Though the Ørsted Kalundborg CO₂ Hub has received funding from the Danish Government, the revenue from carbon removal certificates makes up a significant portion of the business case, and the project wouldn’t have been possible without the additional funding from the sales of carbon removal certificates.

Ørsted Kalundborg CO₂ Hub complies with the general additionality criteria 1) financial additionality, meaning that the project is unfeasible without the revenue from the sales of carbon removal certificates, 2) regulatory additionality, meaning that the activity mustn’t be mandated by law, and 3) that it’s not common practice, as installing carbon capture is not a standard or common technical aspect of CHP plants.

The Ørsted Kalundborg CO₂ Hub shows how private companies can contribute to realising ambitious climate projects and scaling new climate technologies.
Can Ørsted claim to generate climate-negative heat and power from its CHP plants when carbon certificates are sold to third parties?
No. When selling a carbon removal certificate to another company for use in their voluntary reporting, it’s recorded in the registry of an independent third party to ensure that the same carbon removal isn’t counted by two companies.

This means that e.g. our heat customers can’t claim climate negative district heating when Ørsted sells certificates to third parties.