Big things are happening at Hafslund’s waste incineration plant at Klemetsrud—quite literally. Construction of the carbon capture facility is already clearly visible in the surrounding area, as its tallest component—the absorber—is beginning to take shape. The project is one of Norway’s largest climate initiatives and will, among other things, help significantly reduce Oslo’s fossil CO2 emissions. When the facility becomes operational in 2029, it will capture both fossil and biogenic CO2, making it carbon-negative—in other words, it will remove CO2 from the natural carbon cycle.

High level of activity

The construction project includes both the capture facility at Klemetsrud and a CO2 terminal at the Port of Oslo. Activity at the construction site is in full swing. Around 500 people will be involved in building the facilities at Klemetsrud and the Port of Oslo. The project includes deliveries from several locations across Europe, including Greece, Italy and Bosnia.

So far, the work has primarily involved groundworks, while the facility’s tallest component, the absorber, is also being erected. This is where the magic will happen: the CO2 will be separated from the flue gas (see illustration).

Once the groundwork is complete, all the components will be assembled. This will begin in early 2027.

– Challenging to work in parallel in a confined space

The facility under construction is extensive. Among other things, 1,365 tonnes of steel—equivalent to six Statues of Liberty!—and 16.2 kilometres of piping must be installed, all within a small area.

– Construction of the carbon capture facility must be carefully planned and carried out in stages to make room for construction machinery and cranes. The construction site is confined to a narrow area between the existing buildings and the rock face leading up to Klemetsrudveien. Some of the installation must be built on site because the components are too large to be transported by road. It is challenging for all the suppliers involved to work in parallel on such a confined construction site. This requires effective coordination and collaboration, and shift work will need to be introduced at times, says Kjetil Bollestad, CCS Project Director at Hafslund Celsio.

He is impressed by the work being carried out. AF Gruppen is responsible for the groundwork and technical building, after which Aker Solutions and SLB Capturi will take over one area at a time and install the process plant, including components and technical equipment, together with their suppliers.

– They have built some of the most advanced facilities in the world. We are in good hands, says Bollestad.

The surplus energy is used to produce district heating

The nearest neighbour is the Klemetsrud transformer substation. Elvia is building a new transformer there to supply more electricity to the new capture plant.
The new capture plant will require 27 MW of additional capacity from Elvia, approximately 7.5 MW more than the current requirement.

To ensure the supply of district heating to customers, Hafslund is installing what is likely to be Europe’s largest heat pump to recover heat from the capture process.

“Today, we use surplus heat from waste incineration to generate electricity and provide district heating. The capture facility will use heat from waste incineration in the CO₂ capture process, while the heat pump will raise the temperature of the heat recovered from the capture process. Once the carbon capture facility is operational, this will enable us to supply more district heating than the waste incineration plant does today. The capture process will use 40 MW of heat from the incineration plant. The new 60 MW heat pump will enable us to supply an additional 20 MW of district heating,” says Bollestad.

The world is watching

Hafslund’s carbon capture facility is expected to be among the world’s first full-scale carbon capture facilities linked to waste incineration. The project has therefore attracted considerable international interest and is being closely followed by governments, industry groups and cities seeking solutions to reduce emissions. In 2025, approximately 50 delegations visited Klemetsrud.

“This autumn, we have welcomed delegations from several European countries, as well as from Japan, India and Taiwan,” says Truls Jemtland, Head of Communications at Hafslund Celsio.

– By capturing carbon from waste incineration, Hafslund can develop one of the world’s first waste-to-energy carbon capture facilities as part of a complete value chain. This will allow us to show other cities how to manage non-recyclable waste efficiently while producing heat and electricity for their residents. In addition, we can help remove large volumes of CO2, says Truls Jemtland.

A project of great importance to Oslo

The carbon capture project is part of Norway’s full-scale carbon capture, transport and storage project, Longship. Once completed, the facility will capture around 350,000 tonnes of CO2 annually from the waste incineration plant. This represents approximately 90 percent of the emissions from the incineration process and will reduce Oslo’s fossil greenhouse gas emissions by 20 percent.

Once the CO2 has been captured, it will be cooled and compressed into liquid form before being transported to the Port of Oslo.

“This means 1–2 electric transport trips per hour every day from Klemetsrud to the Port of Oslo. These will mainly take place outside rush hour,” says Bollestad.

From the Port of Oslo, liquid CO2 will be transported by ship to the Northern Lights facility in Western Norway, before being pumped deep beneath the seabed for permanent storage.

The project has a long history. Work on carbon capture at Klemetsrud has progressed through various phases since the City of Oslo launched its climate strategy in 2015. Following several years of studies, cost assessments and further development of the concept, the decision was made in 2025 to implement the project.