MISO’s inaugural long-term load forecasting survey among its membership shows the possibility of 82 GW in data center load by 2044.
The RTO said responses to its pilot survey place data center demand at the top of the list. However, 55 of the 82 GW have been categorized as “low confidence.”
“There’s no surprise here that data centers make up the bulk,” Dominique Davis, manager of strategic insights, said Feb. 12 during a webinar hosted by MISO.
MISO plans to use the survey results to publish a finalized long-term load forecast in April 2026. The RTO said it will use complementary research and third-party analysis to supplement incomplete data to produce a final, nearly 20-year load forecast.
Beyond data center load, members reported the potential for an additional 4 GW in manufacturing load and 3 GW of other, miscellaneous load.
By MISO’s count, public announcements of large loads coming online by 2030 have more than doubled in the span of a year; however, the RTO warned that public announcements of large load do not necessarily reflect firm commitments. In 2024, MISO counted 14 GW of large load announcements. In 2025, it recorded 43 GW.
MISO Central — one of the RTO’s three reliability regions, containing Wisconsin, Michigan, Indiana, Illinois, and parts of Missouri and Kentucky — contains the most potential for large loads, at nearly 40 GW by 2030. However, more than half of that is what MISO considers “low confidence.”
“While this surge is notable, we’ve also observed cancellations for various reasons,” Davis said.
MISO divided load additions into high-, medium- and low-confidence categories:
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- High-confidence additions represent those that have associated interconnection agreements in place with regulators’ knowledge and construction underway;
- Medium-confidence projects are those that have been submitted through a MISO planning process or have been publicly announced, but construction has not yet begun; and
- Low-confidence projects are those in the early stage that are not in MISO’s planning process but appear in integrated resource plans or remain conceptual.
MISO’s data collection turned up eight spot loads that would require more than 1 GW, “which compose a significant reliability risk in the future,” Davis said.
The RTO said it cannot share its load forecasts on a local resource zone level because of utilities’ insistence on confidentiality and their nondisclosure agreements with developers.
To collect intel for its long-range pilot, MISO introduced confidentiality provisions that allowed it to receive greater insights from utilities, even when it could not share specific breakdowns. By contrast, the RTO’s 2024 load forecast relied on internally culled data from public sources.
MISO said it received submissions in response to its pilot survey from 44 entities, which are responsible for about 80% of the footprint’s load. “That’s a huge step towards transparency,” Davis said.
The RTO found that 31 responses on large loads additions match public announcements, she said. “So, we did get a good representation in that area.”
MISO is already home to about 17 GW in large loads.
Waning After 2035?
Davis said the survey results show that large load planning tapers off after the first 10 years of the survey and stagnates beyond 2035. MISO said most entities did not provide data on large loads beyond 2035.
Additionally, MISO said only 60% of its respondents even filled out the section on large load. “Confidentiality limits reduced data sharing and response rates, complicating double-counting checks and mapping large load submissions,” it said.
According to data from Yes Energy, over the next decade, the MISO territory is due to host or be affected by 50 data centers either already under construction or in advanced development; 74% of them list in-service target dates in 2026 or 2027. All of them have a 60% or better chance of being built. More than a dozen data center projects would be near Chicago.
Davis said MISO does not believe the responses are an indication that data center load would stagnate. She said for the final forecast, the RTO would fill in some expectations rather than accept an actual leveling-off of large load expectations.
Mississippi Public Service Commission consultant Bill Booth asked why MISO would not take members at their word and stop forecasting more dramatic data center growth beyond 2035. He said there could be improvements in data center management and strides made in efficiency that lead to demand inertia.
Davis said the industry does not appear primed for a slowdown by 2035. “We do understand this comes in phases, but how much energy they’re going to need in phases is not well understood.”
Stakeholders asked how much double-counting of facilities might be in the pilot survey.
Davis said MISO was able to pinpoint a few likely cases of hyperscalers shopping two locations, but she said survey answers left out a lot of identifiable information, especially for potential large loads in the nascent, “low-confidence stages.”
Booth suggested that MISO strike all low-confidence load growth from its forecast. He said he did not want up-in-the-air figures to influence transmission planning.
“Why would you use any information that isn’t reliable? Building a base on shaky data ensures that ratepayers are going to be paying for more transmission than needed,” he said.
Davis said MISO would not include 100% of low-confidence projects in its forecast. It will provide more data on its process when it releases the results in April, she said.
The Union of Concerned Scientists’ Sam Gomberg pushed back on the notion that MISO should wait and act on only loads that are a sure thing. He said that’s not how the electricity industry works.
“If we waited for the load to arrive, it’d be sitting there in the dark while we built,” Gomberg said.
He said MISO’s far-from-perfect effort is nevertheless a good start and shows the need to “drive forward on this low-certainty chunk of load” to figure out what could pan out. He said MISO should strive to provide more transparency.