MISO expects to manage a 163-GW demand peak by 2035, and potentially 230 GW by 2046 in a high-demand environment, according to the RTO’s first crack at comprehensive long-term load forecasting.
The grid operator said data center load is the most consequential variable in its 20-year view of load growth.
MISO’s projections show a 163-GW coincident peak in 2035. That could become more than 180 GW by 2046 at a 2% compound annual growth rate. But the RTO said a 3% CAGR could have it topping 230 GW in peak demand in two decades.
The RTO managed an approximately 121-GW coincident demand peak in 2025.
The latest figures show that what was considered unlikely two years ago has become the norm. The RTO’s “high” scenario from its less intensive load forecasting effort in 2024 now mirrors its “current” trajectory. (See MISO Switches to In-house Load Forecasting to Gauge Soaring Demand.)
“What was previously upside is now base case,” Brad Decker, of MISO’s Strategic Insights Group, said during an April 13 stakeholder workshop on the forecast.
Decker said the 20-year forecast reflects “evermore announcements and expectations” for data center infrastructure through 2035.
MISO said it’s in an AI “super cycle,” with 22 GW of data center demand alone projected by 2030. It found that data centers could proliferate at an 18% CAGR through 2046.
“Data centers are scaling quickly and introducing a lot more local planning dynamics,” Decker said. “A single project can rival the load of a mid-size city.”
Decker said MISO discovered that since its most recent load check-in in 2024, trends are “tilting” toward more traditional generation resources to handle the ballooning load, combined with “softer expectations” for electrification-driven load growth.
Additionally, loads are poised to become more consistent with the “structural” change of around-the-clock data center demand, Decker said. He said MISO’s system load factor is set to increase from about 63% currently to nearly 70% by 2040.
However, Decker said the trajectory of AI is uncertain, including “monetization challenges” that could slow investment and consolidate the industry. He said there “are signs” of obstacles already, comparing data center announcements to restaurant reservations in which only five to six people ultimately show up for a reservation for 10.
MISO included a lower growth case that contemplates a slowdown in data centers in its range of possibilities. In that scenario, it might experience a 1.1% CAGR and manage an approximately 150-GW peak by 2046.
During the Board of Directors’ meeting in March, CEO John Bear said the expected 2% rate “is quite a bit away from the 0.4%, 0.2%” annual growth the RTO had been managing for years.
At the workshop, Executive Director of Markets and Grid Research DL Oates said MISO focused on piloting a long-term load forecast because of demand brought on by data center growth.
“The growth expected going forward is quite different than what we’ve experienced,” Oates said.
If MISO is to oversee a 163-GW peak in less than a decade, it needs significantly more generation. The RTO reported in March that its expedited interconnection queue could soon add 19 GW in nameplate capacity to the footprint. It said it is ready to clear or has cleared 11 GW of projects to connect and is studying an additional 8 GW for interconnection. (See MISO: NERC to Dial Down RTO’s Risk Level; Members Create Large Load Working Group.)
MISO’s standard generator interconnection queue, on the other hand, contains 192 GW, which is set to dwindle. (See MISO Plans to Change Accounting Practices as Record Queue Exits Could Raise Rates.)
The grid operator also reports it is sitting on 76 GW in generation with approved interconnection agreements that have yet to be built. It’s urging developers to bring their projects online as quickly as possible or let it know if those projects cannot be completed.
Oates said the pilot long-term load forecast won’t be used in 2026 in the 20-year futures scenarios that influence long-term transmission planning, but it would be incorporated in subsequent years. The informational nature of the pilot long-term load forecast is nevertheless valuable and will serve as a guide for gathering data from members, he said.
“We’re trying to get this long-term load forecast on a predictable, annual cadence,” he said.
In future annual load forecasts, MISO plans to refine its member data collection process, improve geospatial load growth results, and incorporate extreme weather and its influence on load. It also has hired energy analytics company Kevala to update its projections for distributed energy resources.
Decker said that once MISO factors in demand-side projections, it would produce a gross load forecast in addition to its net load forecast.