Southeastern Wisconsin and the Chicago area are emerging as major players in the national data center explosion, most notably with Microsoft’s $3.3 billion planned data complex near Racine, Wisconsin.

Clean energy advocates in the region say data centers pose both a risk and an opportunity as they can put major stress on the grid, prolong the lives of coal plants and spark new natural gas plants, but also facilitate significant renewable energy investment. Wisconsin utility We Energies, for example, cited demand from data centers in its recent requests to the Public Service Commission for 1,300 megawatts of new gas generation. Microsoft, meanwhile, has promised to build renewables in the state while also likely creating demand for new or continued fossil fuel energy.

The organization Data Center Map shows more than 100 data centers in the Chicago area and a handful in southeastern Wisconsin, often located on the site of former coal plants or industrial operations. A data center is underway on the site of the shuttered State Line coal plant just across the border from Chicago in Indiana. The data center developer T5 recently announced plans for four to six data centers totaling 480 megawatts of capacity and costing as much as $6 billion in the Illinois town of Grayslake near the Wisconsin border, adding to data centers it already runs in the region.

Virginia has long been known as “Data Center Alley,” with about 70% of global internet traffic passing through its servers, according to the Wall Street Journal. Dominion Energy said that because of data centers, its electricity demand in Virginia could quadruple and represent 40% of total demand in the state over the next 15 years. Georgia and Tennessee have also seen much data center construction and speculation. Utilities like TVA, Duke and Dominion have announced plans to build more gas plants and keep coal plants open longer in that region, along with building renewables.

Meanwhile, some experts say the Great Lakes region is an increasingly promising spot for data centers because of its cooler climate that reduces energy demand and the availability of water.

“There is no better place” for data centers than the Upper Midwest, said Josh Riedy, who helped design North Dakota’s first tier-three data center, referring to a data center with high reliability — on a scale of one to four tiers — that includes multiple power sources. Riedy also founded Thread, a grid maintenance software company that he’s marketing as especially helpful to serve data center demand.

“The Upper Midwest can export data around the globe,” Riedy said. “We’re starting to see the tide turn, it’s just natural.”

Find out more: Wisconsin Watch