Watershed customers Aledade, Canva, Samsara, SKIMS, Skyscanner, Wise, and Zendesk are participating in a $48.6M offtake agreement with Stockholm Exergi, which retrofits existing biomass energy facilities to capture the carbon emitted during biomass production. The agreements were facilitated through Watershed’s partnership with Frontier, the advance market commitment for permanent carbon removal.
Exergi will retrofit a state-of-the-art district heating facility in downtown Stockholm, Sweden—the first commercial-scale carbon removal retrofit on a biomass-fueled heating facility. The KVV8 power station combusts woody biomass waste (like treetops, branches, and saw mill dust) sourced from Sweden and nearby countries in Europe to produce heat and electricity for 800,000 Stockholm residents. After biomass combustion, the CO2 concentration in the resulting gas is 18-19%. The retrofit will react to the CO2 with potassium carbonate at high pressure, heating the resulting potassium bicarbonate, and then condensing out the water vapor to leave the CO2, which is then transported via ship and permanently sequestered deep underground. At scale, these kinds of bioenergy retrofits could generate 0.5-1.0 gigatons of carbon removal per year at low cost.
Exergi’s CDR retrofit will remove 800,000 tonnes of CO2 per year starting in 2028, with a meaningful proportion of the first three years’ output going to Frontier buyers, including Watershed’s participating customers and members of Frontier: Frontier founding members Stripe, Alphabet, Shopify, Meta, and McKinsey Sustainability; as well as additional members Autodesk, H&M Group, JPMorgan Chase, and Workday. These companies can use the carbon removal credits against their own carbon footprints, while supporting the growth of new permanent carbon removal technologies necessary to achieve global climate goals. Read more about this deal here.
