Microsoft embarks on green concrete trials to decarbonise datacentre builds

Microsoft is taking steps to cut the amount of embodied carbon contained within the concrete and steel used to build its datacentres as part of its ongoing push to become a carbon-negative entity by 2030.

The software giant is experimenting with adding a microalgae-based limestone, as well as several other additives, to the concrete mix used to lay the foundations for its datacentres to help decarbonise its server farm builds.

The trial is taking place in Quincy, Washington, and will see Microsoft test out a series of concrete mixes that it hopes can lower the embodied carbon in concrete by more than 50%.

“The concrete mixes piloted in Quincy include one with biogenic limestone, one with fly ash and slag that are activated with alkaline soda ash, and one with both the alkali-activated cement and biogenic limestone,” said Microsoft, in a blog post.

The fly ash and slag is derived from industrial waste that is generated from coal combustion and steel making, while the biogenic limestone is sourced from a company called Minus Materials, which is in the throes of trying to commercialise a production process for the material pioneered by the University of Colorado, Boulder.

“The project goal is to test mix designs that can lower embodied carbon in concrete by more than 50% compared to traditional concrete mixes,” said Microsoft.

As Microsoft acknowledges in the post, these materials and mixes are an “imperfect solution” to the problem of embodied carbon in concrete, but they are a “start”.

“The biggest enemy to progress is this concept that it has to be perfect before you start,” said Sean James, senior director of datacentre research in Microsoft’s datacentre research team.

“The best way to make actual impact is to go out there with a good enough solution and what’s good enough now is using these things that can bring down the carbon, so we can start making an impact right away.”

The company said the manufacturing of concrete is responsible for around 8% of global greenhouse gas emissions, whereas steel accounts for around 7%.

With this in mind, the company is keen to do what it can to find ways to reduce the amount of greenhouse gases associated with its own datacentre builds and, in turn, shrink the size of its environmental footprint accordingly.

Specifically, Microsoft said it wants to “ratchet down embodied carbon in concrete and other building materials to zero” and potentially make them carbon-negative.

To achieve this, it will be learning on the investments it has made via the Microsoft Climate Innovation Fund in several early-stage companies, the blog post confirmed.

News of the pilot projects comes on the back of Microsoft signing an open letter, along with Amazon Web Services (AWS), Google and Meta, that featured a call to action for operators to use greener concrete in their datacentre builds.