Microsoft Corp. wants to use hydrogen fuel cells to provide backup power for its Azure data centers and reduce carbon emissions.

The company detailed its plans in a blog post today, saying that it has reached a notable technical milestone toward realizing that vision. 

Hydrogen fuel cells are an emerging type of generator designed to be more environmentally friendly than traditional diesel generators. A hydrogen fuel cell produces electricity by combining hydrogen with oxygen in a process that doesn’t emit any carbon dioxide. The only byproducts are vapor and warm air.

The technology is of interest for Microsoft because the company’s data centers, like most modern data centers, have onsite diesel generators to provide backup electricity. The generators are responsible for keeping servers running if there’s a power grid disruption. Diesel fuel accounts for less than 1% of Microsoft’s emissions, according to the company, and it’s hoping to replacing its generators with hydrogen fuel cells might be a way of reducing that number even further.

Microsoft detailed today that its engineers have been experimenting with a 250-kilowatt fuel cell system to test the technology’s feasibility. Last month, they reached what the company touts as a notable operational milestone. The 250-kilowatt system achieved an industry first after successfully powering a row of 10 data center server racks for 48 consecutive hours.

“It is the largest computer backup power system that we know that is running on hydrogen and it has run the longest continuous test,” said Mark Monroe, the Microsoft infrastructure engineer who led the team behind the experiment. 

In the wake of the successful test, Microsoft now plans to procure a much larger 3-megawatt fuel cell system with similar capacity as the backup generators at Azure data centers. The goal is to test how well a larger system could function as a backup electricity source. Monroe said that Microsoft hopes to be a catalyst in the formation of a “hydrogen economy.”

Providing 48 hours’ worth of backup power for an Azure data center would require about 220,000 pounds of hydrogen. The company says its engineers have already held initial conversations about how to procure the necessary fuel as part of the effort to deploy the technology. According to Microsoft, one potential implementation approach would involve pairing fuel cells with a hydrogen storage tank and an electrolyzer that extracts hydrogen and oxygen from water molecules. 

Photo: Microsoft