Senken signs 50,000-ton biomass carbon removal deal with Carbonsate

ESG Today reported Tuesday that Senken has agreed to buy 50,000 tons of permanent carbon removal from Carbonsate, with the credits coming from Carbonsate's biomass burial project in Namibia. Deliveries start this year and run through 2028. In the two firms' account, the agreement is the largest biomass storage deal signed in Europe to date, the second-largest buyer commitment in the biomass geological storage category worldwide, and the largest for a project operating in Africa.

Biomass burial works by putting waste wood in sealed underground chambers. Inside, the wood has no oxygen and no weather, so it will not rot or burn; the carbon stays trapped for centuries. The method needs no power-hungry capture machinery, and Carbonsate says that is why permanent removal through burial costs a fraction of direct air capture.

Senken is a buying agent, not the end user. Founded in 2022 and headquartered in Berlin, the firm vets credits for European companies, running each one through its Sustainability Integrity Index. That screen checks more than 600 data points and, according to Senken, rejects 95% of the projects it evaluates. Deutsche Telekom, Vodafone, and DZ Bank are among its clients.

Carbonsate, a Berlin developer, builds and runs the storage sites. Each carries its own monitoring, reporting and verification system, and each is independently verified against the Puro.earth standard. Co-founder and chief executive Johanna Broell said the multi-year agreement gives developers the confidence to build before demand is proven, and it backs expanding the company's Namibia sites.

Senken frames the contract as a hedge against a supply shortage. Too few quality projects satisfy the number of companies chasing permanent removal, and net-zero plans tend to land on the same shortlist of credits, according to the firm. Locking in multi-year volume, it argues, gives European clients both access and a predictable price.

The deal's significance is not the 50,000 tons, which is modest by any broad carbon-market measure; it is that a volume that size can rank among the largest buyer commitments in its category. That only happens when the category itself has little committed volume. Senken's 95% rejection rate reinforces the point: verified permanent removal is scarce, and buyers are signing contracts before projects have much of a delivery record.

The unfilled part of the ledger is operational. The Namibian site's delivery record is unwritten as the contract begins, and the monitoring that backs each storage site must keep pace as Carbonsate expands. If deliveries land on schedule with the audit-ready documentation Senken promises its clients, the contract looks like an early template for pairing corporate buyers with removal developers. If deliveries slip, it is a reminder of what a multi-year carbon contract is worth when the project behind it is still being built.