Microsoft Corp. has signed a binding agreement to purchase up to 623,000 metric tons of low-carbon cement from Sublime Systems over the next six to nine years, marking a major step in decarbonizing construction supply chains and scaling breakthrough clean technologies in heavy industry.
The deal, announced Wednesday, will see deliveries from Sublime’s first commercial factory in Holyoke, Massachusetts, as well as a future full-scale production facility.
The agreement enables Microsoft to integrate Sublime Cement into its global infrastructure projects, regardless of location, through a model that decouples physical materials from their environmental attributes.
Reducing Emissions in Construction
“This transaction allows Microsoft to reduce construction emissions with certainty and scale, while supporting an innovative American-made technology,” said Jeff Leeper, vice president of global datacenter construction at Microsoft. “We need breakthrough, reimagined products like Sublime Cement at scale to reduce emissions — both at Microsoft and globally.”
The novel contract includes the ability to purchase environmental attribute certificates separately from the physical cement, a mechanism modeled after renewable energy certificates.
This flexibility helps overcome the traditional geographic limitations of cement sourcing, allowing Microsoft to apply the emissions-reduction value across its data centers, offices, and other infrastructure.
Katie Ross, director of carbon reduction strategy & market development at Microsoft, called the approach “critical to expanding the market for climate solutions” and highlighted the role of third-party verification and a forthcoming book-and-claim system to ensure transparency and accountability.
Avoiding Emissions at the Source
Sublime Systems, a Massachusetts-based startup, is commercializing a proprietary electrochemical process to manufacture cement without fossil-fueled kilns or limestone decomposition—the primary sources of emissions in traditional cement production.
The result is what the company calls a “true-zero” process, eliminating the need for carbon capture and reducing pollution across the board.
“Microsoft is stepping up as the first customer for our future megaton-scale plant,” said Dr. Leah Ellis, CEO and co-founder of Sublime Systems. “This enables us to accelerate our scale-up and address the financing challenges that have long plagued clean industrial technologies.”
The company’s technology replaces ordinary portland cement, the widely used binder in concrete, with a drop-in, ASTM-compliant product that boasts improved durability and aesthetic qualities.
Sublime Cement has already been successfully used in commercial projects and is being adopted by leading general contractors.
Federal Support and Industrial Revitalization
Sublime’s Holyoke facility — currently under development — is supported by an award of up to $87 million from the US Department of Energy. The site leverages existing industrial infrastructure in a former paper manufacturing hub, contributing to job creation and domestic supply chain resilience.
The Holyoke plant is expected to serve as a risk-mitigated bridge to megaton-scale production, a trajectory that the company says will be accelerated through Microsoft’s commitment.
Setting the Stage for a New Market Model
This agreement follows a 2024 memorandum of understanding between Microsoft and Sublime to develop a verifiable and catalytic book-and-claim system for materials. The model is being advanced with support from organizations such as RMI and the Center for Green Market Activation.
As corporate buyers seek to reduce Scope 3 emissions, deals like this could help redefine how clean industrial materials reach market scale.
“With this purchase, Microsoft is not just a customer — they’re helping to build the market infrastructure that clean tech needs to succeed,” Ellis said.
