The Intergovernmental Panel on Climate Change (IPCC) considers carbon capture as a crucial tool for achieving the goals of the Paris Agreement. To reach global net-zero by 2050, up to 10 billion tonnes of CO2 will need to be removed. 

In Denmark, the technical potential for carbon capture is estimated to be around 5 to 10 million tonnes (Mt) annually. To meet the Danish government’s ambitious goal of a 110% reduction in greenhouse gas emissions by 2050, Denmark will require at least 8 Mt of negative emissions per year. In addition to emissions reduction, biogenic CO₂ will also be essential in the production of sustainable fuels and materials, helping to eliminate dependence on fossil fuels. 

However, biogenic CO₂ is expected to become a limited resource. For this reason, efficient energy use of biomass may play a significant role in securing future supply of biogenic CO₂. 

From early 2026, Ørsted will capture 430,000 tonnes of CO2 annually from two combined heat and power plants, storing the captured CO2 in the North Sea. 

The carbon capture units, supplied by SLB Captur, are expected to capture approximately 280,000 tonnes of CO2 annually from the woodchip-fired Asnæs Power Station in Kalundborg, whereas the straw-fired Avedøre Power Station in Greater Copenhagen is estimated to capture around 150,000 tonnes of CO2 annually. Ørsted’s carbon removals are certified by an independent third party.  

The project also marks the first-of-its-kind large-scale agreement with Microsoft for the purchase of carbon removal credits, totalling 3.67 million tonnes. 

The capture units use amine solvents to absorb the CO2 from the flue gas produced by the heat and power plant. The captured CO2 is then purified, compressed, and liquefied, making it ready for transport. CO2 captured from Avedøre Power Station in Greater Copenhagen will be transported by truck to Asnæs Power Station in Kalundborg. 

The Asnæs Power Station will not only serve as a shipping hub for Ørsted’s own CO2, but also for CO2 from other emitters. For this reason, the carbon capture area of the site is named Ørsted Kalundborg CO2 Hub. From Kalundborg, the CO2 will be shipped by Ørsted’s partner Northern Lights to their onshore terminal in Øygarden, Norway. 

How CO2 is stored safely beneath the seabed
At Øygarden, the CO2 will be pumped through a subsea pipeline to the Aurora storage complex, located approximately 100 km offshore. There it will be injected into a 2.6 km deep saline aquifer, which contains two primary sand reservoirs, overlaid by a cap rock that seals the storage site and ensures long-term containment.  

The sand reservoirs have pore space between a rock framework. The porous space is currently filled with brine, a concentrated solution of salt water.

The injected CO2 will displace the brine and stay trapped in the porous space. A small portion will mineralise, some will dissolve in the brine, and most will be permanently trapped in the rock formation. 

Turning residues into renewable heat and creating negative emissions
Ørsted’s heat and power plants use biomass such as straw or wood chips to provide heat and electricity to Danish households. The bioenergy is renewable as the biomass is from sustainably managed forests and agricultural areas that already produce products and commodities for society. In short, instead of using fossil fuels, Ørsted’s heat and power plants use biomass from waste and residues. 

Residues from forests are replanted, meaning the CO2 absorbed during regrowth balances out the CO₂ stored in the biomass. By capturing and permanently storing the CO2 emitted when burning the residues, the net amount of CO2 in the atmosphere is reduced, making the process carbon-negative. 

The Danish Energy Agency has awarded Ørsted a 20-year subsidy contract for Ørsted Kalundborg CO2 Hub, contributing directly to Denmark’s climate targets. The project demonstrates how collaboration across operators, technology providers, offtakers, and policy makers can reduce the cost and time to market of decarbonisation solutions