Microsoft has announced an agreement with US-based company Sublime Systems to buy more than 600,000t of green cement as part of its efforts to both reduce its carbon footprint and help the sustainable materials market.
Spun out of MIT in 2020, Sublime Systems has developed a proprietary process that utilises an electrolyser to produce cement at ambient temperatures, replacing energy and fossil fuel-intensive kilns, and enabling the use of calcium sources as an input material, avoiding the release of CO2 from limestone input. As part of the process, limestone is converted to lime at room temperature, with the CO2 produced during this conversion process easier to capture.
The agreement allows for the deployment of up to 622,500t of cement produced at Sublime Systems’ first commercial factory and subsequent full-scale factory over six to nine years, with Microsoft to purchasing Sublime cement for construction projects when geographically possible. Microsoft will also be able to purchase the environmental attribute certificates (EACs) of Sublime cement separately from the physical material—a similar mechanism to decoupling renewable energy certificates from the use of the actual energy produced.
Jeff Leeper, VP of Global Datacenter Construction at Microsoft, said: “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. We need breakthrough, reimagined products like Sublime Cement at scale to reduce emissions—both at Microsoft and globally.”
Sublime said that the agreement, especially the option for Microsoft to buy EACs, will help accelerate the opening of its first commercial factory and scale its production.
Dr Leah Ellis, Sublime Systems CEO and co-founder, added: “This purchase enables Microsoft to access Sublime’s low-carbon cement technology regardless of where their construction is. 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.”
The announcement comes days after the news that venture platform Suffolk Technologies, part of US-based builder Suffolk, plans to invest in Sublime Systems.
