Microsoft has agreed to purchase 1.1 million tons of carbon removal credits from Hafslund Celsio, an energy from waste (EfW) and carbon capture and storage (CCS) firm.

The credits, set to be delivered over a ten-year period, will be generated by a CCS project under development at the site of Norway’s largest EfW plant, Celsio, in capital city Oslo.

The plant, which processes around 350,000 tons of residual waste every year, will be retrofitted with a CCS system to capture the emissions generated through the incineration process.

Incineration produces two forms of CO2 emissions, namely, biogenic CO2 from the burning of organic material and fossil CO2 from the burning of inorganic waste such as single-use plastics. The purchase will support the construction of what Hafslund claims is the “first ever” retrofit of an EFW to deliver carbon removal.

“The agreement with Microsoft is a significant contribution to the commercial success of Hafslund Celsio’s carbon capture and storage project. Microsoft’s purchase is a strong recognition of our CCS project and highlights the crucial role of the waste-to-energy sector as a credible provider of permanent carbon removals,” said Martin S. Lundby, CEO, Hafslund Celsio.

When operational, the CCS system is expected to capture 400,000 tons of CO2 every year. It is estimated to commence operations in 2029, with the captured CO2 subsequently transported to the Northern Lights carbon storage facility for permanent storage in a reservoir 2,600 meters (8,530 ft) under the seabed in the North Sea.

The first phase of the project is the transport and storage component of Longship, the Norwegian Government’s full-scale carbon capture and storage project. Longship is expected to begin operations in the summer of 2025.

“Hafslund Celsio’s project turns waste into valuable carbon dioxide removal, while providing the city of Oslo with heating and helping Norway meet its climate goals”, said Brian Marrs, senior director, Energy & Carbon Removal, Microsoft. “We appreciate Hafslund Celsio’s central role in Project Longship and are pleased to see this project develop.”

This is the second major offtake deal signed by Hafslund, following an agreement in April with carbon consortium Frontier, which counts Google and Meta as members, for the purchase of 100,000 tons of carbon removals.

The deal is the latest in a long line for Microsoft this year, as it consolidates its position as the premier corporate carbon offtake buyer. The hyperscaler has signed several deals with companies exploring CCS technology, as part of its offtake strategy.

In April, it inked a deal with CO280 to purchase 3.685 million tons of carbon credits over a 12-year period. CO28 retrofits existing pulp and paper mills with CCS to capture biogenic carbon from boiler stack emissions for permanent storage.