Sublime Systems and Microsoft Sign Binding, Long-Term Purchase, Transforming the Market for Clean Cement

Microsoft is purchasing up to 623K tons of cement products from Sublime’s first commercial factory and subsequent full-scale factory over a six- to nine-year period.

The transaction enables Microsoft to use low-carbon Sublime Cement® to reduce corporate emissions, unconstrained by the geographies of its construction projects.

In its latest move to shape its future supply chain, Microsoft is contracting with Sublime Systems to verifiably reduce construction emissions through a binding purchase of low-carbon cement manufactured with Sublime’s breakthrough American-invented technology.

Microsoft’s purchase will deploy up to 622,500 metric tons of Sublime Cement® over a six- to nine-year period. Deliveries will come from Sublime’s first commercial factory in Holyoke, Mass. and its subsequent full-scale production factory. Sublime’s Holyoke plant is designed to eliminate scale-up risk to progress to full megaton-scale Sublime plants—a trajectory accelerated by Microsoft’s purchase. Sublime’s manufacturing process avoids conventional sources of carbon emissions and other pollution, a “true-zero” technology that forgoes the need for carbon capture, enabling cost competitiveness at full-scale production.

“In designing creative transactions such as this one with Sublime, Microsoft aims to accelerate the mass production and adoption of clean construction materials, enabling innovators to overcome the real, acute challenges of scaling in heavy industries with existing manufacturing capacity,” 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.”

“This purchase enables Microsoft to access Sublime’s low-carbon cement technology regardless of where their construction is,” said Sublime Systems CEO and Co-founder Dr. Leah Ellis. “This solves a previously intractable challenge for clean cement scale-up: the lack of long-term cement transactions contrasted with the immediate need for innovators to demonstrate bankable customers to fund their manufacturing. Microsoft is stepping up as the first customer for our future megaton-scale plant, enabling us to more rapidly build and scale Sublime Cement as a global, enduring solution for clean construction.”

Microsoft has secured a priority option to purchase and deploy Sublime Cement in its construction projects when geographically possible, at their datacenters, office buildings, and other infrastructure. Through this novel contract, the environmental attribute certificates (EACs) of Sublime Cement can be purchased separately from the physical cement material—a similar mechanism to decoupling renewable energy certificates from the electron at the point of clean electricity production. This model is powerful when applied to heavy industry like cement, which is typically produced within a tight geographic radius of customer construction projects.

“To reach net zero, the world needs innovative technology solutions like Sublime Cement. At Microsoft, our focus is growing the market for these solutions,” said Katie Ross, Director, Carbon Reduction Strategy & Market Development at Microsoft. “While we prioritize deploying physical material whenever possible, this EAC approach helps both buyers and sellers overcome geographic, supply chain, cost, and other barriers that make it challenging to introduce new technologies.”

Microsoft’s purchase of Sublime Cement EACs will be third-party verified, and it’s expected to be managed on a future book and claim system. This follows a 2024 memorandum of understanding, where the two parties committed to developing a book and claim transaction that was verifiable, additional, and catalytic. It complements efforts from organizations such as RMI (formerly known as the Rocky Mountain Institute), who published a white paper with Microsoft on a book and claim model for the materials sector and who is partnering with the Center for Green Market Activation on the development of a book and claim system in partnership with other leaders in clean concrete technologies.

Sublime is currently developing its first commercial factory in Holyoke, harnessing rich industrial infrastructure to bring quality manufacturing jobs back to a city that was once the world’s biggest paper manufacturer. With an up-to $87 million award from the U.S. Department of Energy, Sublime is working to reshore and modernize American cement manufacturing, strengthen American supply chains, increase energy efficiency, and lead innovation of an essential material. It produces Sublime Cement as an ASTM-compliant replacement in concrete for ordinary portland cement (OPC), which is made in kilns running at 1450°C to decompose the feedstock limestone, a mineral that is roughly 50% CO₂ by weight.

Sublime’s breakthrough electrochemical process breaks down the entirety of its rock and industrial waste feedstocks, avoiding the pollution and waste that have characterized cement manufacturing for over 200 years while improving energy efficiency. Low-carbon Sublime Cement is more durable than legacy OPC and can exhibit premium qualities such as lighter color, desirable for aesthetics and reduction of urban heat island effect.

Microsoft’s binding offtake follows successful commercial deployments of Sublime Cement demonstrating the material poured and placed like conventional cement. Sublime is partnering with industry-leading general contractors to further accelerate adoption through the construction supply chain. To inquire about integrating Sublime Cement into your construction, email partnerships@sublime-systems.com.

About Sublime Systems

Sublime Systems is commercializing breakthrough technology to manufacture cement more energy and resource efficiently. Sublime’s electrochemical, ambient-temperature process breaks down low-value rocks and industrial wastes into its constituents: reactive cementitious ingredients and critical mineral co-products. It avoids the waste and emissions characteristic of portland cement manufacturing while producing a similar ASTM-compliant Sublime Cement® that is more durable, more consistent, and whiter in color than portland cement. Sublime was founded by Dr. Leah Ellis and Prof. Yet-Ming Chiang, both respected experts in materials science and electrochemical systems. The company has raised over $200M in funding from leading tech investors, cooperative agreements with the U.S. Department of Energy, and three of the largest cement producers in the western world: Holcim, Amrize, and CRH. It operates a Somerville, Mass.-based 250 ton-per-year pilot, is developing its first commercial factory in Holyoke, Mass., and has secured offtakes from construction industry leaders and technology companies alike. Learn more at sublime-systems.com or contact partnerships@sublime-systems.com to inquire about working together.

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“We need breakthrough, reimagined products like Sublime Cement at scale to reduce emissions—both at Microsoft and globally," said Jeff Leeper, Vice President of Global Datacenter Construction at Microsoft.