Microsoft is in the final phases of building the $3.3 billion Wisconsin facility it says will be the most powerful AI data center in the world when it comes online in early 2026 to train the next decade of artificial intelligence models. The software giant has already begun staffing the operation and is already planning further expansion, with another $4 billion to be spent in the next three years to build a second data center of similar size and scale — bringing the total investment in Wisconsin to more than $7 billion. Located in Mount Pleasant, the nearly completed facility will be the first in what Microsoft is calling its Fairwater family of hyperscale data centers.

It “initially will be used to train OpenAI models,” reports The Wall Street Journal, which said, based on an interview with Microsoft President Brad Smith, that “in the future it could also include other tenants, including Microsoft itself.”

The Mount Pleasant complex “includes three buildings with a combined 1.2 million square feet across 315 acres,” WSJ writes. Inside, it “hosts hundreds of thousands of Nvidia GB200 GPUs” that at the rack level, “communicate at terabytes per second.”

Smith writes in a blog post that the clusters are “connected by enough fiber to wrap the planet four times over” with the processing power to train the next generation of frontier AI models, “delivering ten times the performance of today’s fastest supercomputers.”

“Microsoft is making big advancements in terms of sustainability,” TechRadar explains of the Mount Pleasant plant. “The center will be 90 percent cooled with recirculated liquid using a closed-loop system with zero operational water waste — the remaining 10 percent of cooling power will come from outside air.”

The company is pre-paying for the plant’s energy at premium prices so local residents won’t get hit with rate hikes as a result of increased demand. And Smith writes in his blog post that Microsoft will “match every kilowatt hour we consume that comes from a fossil fuel source one-for-one with carbon-free energy we put back onto the grid,” including from a new 250MW solar project.

Smith also details educational initiatives, including a partnership with Gateway Technical College to launch Wisconsin’s first Microsoft Datacenter Academy, with plans to train more than 1,000 students in five years for data center roles. Across the state, Microsoft and 40 partners including the University of Wisconsin are aiming to train 114,000 people in AI.

“This facility is more than a technological feat. It’s a promise to grow responsibly, invest deeply, and create opportunities,” said Smith, who admits he holds a personal fondness for the area, having “spent almost five years as a kid going to school and delivering the morning newspaper by bicycle in Mount Pleasant.”

Related:
Microsoft Is Turning Foxconn’s Empty Buildings into the ‘World’s Most Powerful’ AI Data Center, The Verge, 9/18/25
Microsoft 315-Acre Site to House ‘Hundreds of Thousands’ of Nvidia GPUs and Enough Fiber to Circle the Earth 4.5 Times, Tom’s Hardware, 9/18/25