Microsoft has reached a new milestone in its effort to ditch diesel in favor of cleaner energy at its data centers. The company announced today that it successfully tested a hydrogen fuel cell system powerful enough to replace a traditional diesel-powered backup generator at a large data center.

As part of its plans to tackle climate change, Microsoft wants to completely quit using diesel as fuel for its backup power systems by 2030. To keep data centers running 24/7, regardless of power outages, each center is equipped with batteries that temporarily kick in until backup generators are fired up.

For now, those generators run on diesel, releasing air pollutants and greenhouse gas emissions. Hydrogen fuel cells, in contrast, combine hydrogen and oxygen to generate electricity and release heat and water instead of pollution. Big batteries can also run on clean energy but generally don't have the capacity to power a data center for more than a few hours at best.

That's why Microsoft is pretty excited about hydrogen as a fuel and the milestone it just reached: designing and testing a three-megawatt hydrogen fuel cell system that can power around 10,000 computer servers at a data center (or 600 homes, for comparison).

"What we just witnessed was, for the datacenter industry, a moon landing moment," Sean James, Microsoft director of data center research, said in a blog post today.