Microsoft will use generators that rely on diesel or renewable fuel to provide backup power at its data centers as part of the company’s $3.3 billion data center campus in Mount Pleasant.

State environmental regulators recently granted final permits to Microsoft for construction and operation of a data center, as well as changes to a data center already being built on land once slated for development by Foxconn.

The new 1.3 million-square-foot data center will include 40 emergency electric generators with pollution controls and two emergency fire pumps, according to the Wisconsin Department of Natural Resources. Changes to the 1.1 million-square-foot center already under construction will equip 39 backup generators with similar pollution control systems to limit harmful nitrogen oxide emissions. The company has also proposed around 150 more generators at a third 2 million-square-foot data center.