Microsoft is the next large load to sign with the generation company NiSource set up for exactly this kind of customer. On 16 October NiSource announced a 20-year agreement to supply Microsoft's previously announced campus in northwest Indiana. Service is to start in 2028, and NiSource Generation Company LLC (GenCo) will add about 1,100 MW of new generation resources to serve it. Microsoft pays for all the generation and transmission its load needs.
What The Release Says, And What It Leaves Out
The release speaks only of generation resources. It does not say what kind of plant, where it will stand or when construction starts; NiSource will give more operational and financial detail on its third-quarter earnings call. One part is named: GenCo has contracted 600 MW of battery storage under a long-term tolling agreement, to be developed and built by an affiliate of AGP Group. The batteries go into GenCo's pool of assets, which serves several large-load customers rather than one.
The new assets are also to upgrade NIPSCO's transmission system. NiSource now puts the benefit for existing NIPSCO electric customers at about $1.75 billion over the life of its data center contracts, up from the $1.4 billion it had disclosed before, or up to $140 per customer a year. Chief executive Lloyd Yates called affordability a pillar of the GenCo model. Jeff Riles, senior director of energy markets at Microsoft, said the company intends to pay its own way so that its data centers do not push up prices for other ratepayers. The shares rose 2.3 % on the day, Investing.com reported.
The Amazon Template
The structure is the one NIPSCO used for Amazon. GenCo, a separate affiliate, builds and owns the plant for the new large load, so its cost stays out of what existing customers pay. For Amazon that meant two gas-fired plants of 1.3 GW each at the site of the Schahfer coal plant and a 400 MW, four-hour battery, about $7 billion including transmission and all paid by Amazon, for a load that climbs to 2.4 GW by the end of 2032, Utility Dive reported in November 2025. Whether the Microsoft capacity follows the same mix of gas plant and batteries is the obvious question for the earnings call.
Firm Capacity Does Not Retire The Generator Yard
A utility building capacity for one campus changes the backup question less than people tend to think. The campus will still have its own generator sets for the moments when the grid cannot deliver, and in a region where several gigawatts of new load arrive within a few years, those engines may well run more often than a brief written for a strong grid assumed. Northern Indiana gives a generator yard both a real winter and a humid summer, and the sets will stand outdoors for the full twenty years of the contract.
So the detail to listen for is simple: how many of the 1,100 MW are gas turbines or engines that make energy, and how many are batteries that only move it in time. For data center planners in the region that split decides how hard the standby plant will actually be worked.
Sources: NiSource (Business Wire via Yahoo Finance), Investing.com, Utility Dive (2025)
