Microsoft, Hillwood Fight ComEd, We Energies Over Power Deals
Both companies told FERC a signed data center power deal can be canceled or rewritten after the money is committed, a new underwriting risk.
Two of the country’s most closely watched data center developers told federal regulators this month that power agreements they thought were locked in are not safe once a utility decides it wants out. Microsoft asked FERC on August 21 to reject amended transmission agreements for its Mount Pleasant, Wisconsin campus, and PowerHouse Hillwood asked FERC on August 14 to void Commonwealth Edison’s cancellation of a transmission service agreement for its 1.8-gigawatt, $20 billion Joliet, Illinois project. Filed a week apart, both fights turn on the same underwriting risk: a power deal signed and even regulator-approved can still be rewritten or pulled after the capital is committed.
Why it matters
FERC accepted ComEd’s transmission security agreement with PowerHouse Hillwood in docket ER26-1032 on March 10, 2026, and ComEd canceled it anyway on July 24, pointing to a dispute over the timing of a security deposit. PowerHouse Hillwood argues ComEd is using monopoly leverage to kill a deal it no longer wants, the kind of behavior FERC already polices for generator interconnections but has no clear rules against for large loads like data centers. Microsoft’s complaint runs the other direction: it says the agreements American Transmission Co. and Wisconsin Electric Power Co. wrote for its own site would let the utility push infrastructure costs onto other ratepayers and collect duplicate charges, even though Microsoft has publicly pledged to cover its own costs. For a developer, the takeaway is the same either way: land optioned ahead of interconnection, capital committed against a power date, and a construction schedule built around an energization target are all exposed to a utility’s ability to alter or cancel the deal months after signing.
The numbers
PowerHouse Hillwood’s Joliet project is sized at 1.8 gigawatts and $20 billion, with its ComEd transmission security agreement standing for about four and a half months, from FERC approval on March 10, 2026 to ComEd’s cancellation notice on July 24. Microsoft’s August 21 protest targets four amended Large Load Project Commitment Agreements and one Minimum Transmission Charge Agreement between ATC and WEPCo. FERC’s own show-cause orders on large-load interconnection rules, issued in mid-June 2026, gave grid operators until mid-November 2026 to respond.
What’s next
FERC has not ruled on either complaint. PowerHouse Hillwood wants the commission to reinstate the canceled agreement before Joliet loses its place in the interconnection queue; Microsoft wants the ATC-WEPCo agreements sent back for renegotiation. Developers evaluating hyperscale sites elsewhere should track FERC’s broader large-load rulemaking, due by mid-November, which will decide whether utilities can keep canceling deals like this one or whether large loads finally get interconnection protections generators already have. More on the beat at the data center topic hub.