Will SPP double peak demand to 110 GW by 2035?
SPP’s current peak load stands at 56 GW, a record set in August 2023. Today, SPP is planning for a future where this peak could double to 110 GW by 2035.
Large load applications are raising forecasts provided by utilities. But true load growth will likely be lower than what system operators expect.
In this article, we break down SPP's current outlook on load growth along with its uncertainties. We also highlight emerging opportunities where project developers can support growing customer demand.
How much load growth does SPP forecast?
SPP’s latest forecast shows peak demand could reach 110 GW in 2035 - almost twice as high as the historical peak of 56 GW.
SPP builds its peak forecast from Load Responsible Entity (LRE) submissions. Each utility provides a 10-year peak-demand projection, including confirmed ‘firm’ loads and speculative ‘spot’ loads.
What are ‘firm’ and ‘spot’ loads?
Firm loads are loads that have executed formal interconnection agreements with their local transmission operator. They're baked into the base reliability (BR) models and treated as committed demand that SPP must plan to serve. These show up in every future.
Spot loads are large load requests submitted via stakeholder surveys but have not yet completed the interconnection process. They were collected through a voluntary survey sent to transmission operators during the ITP scoping phase. In the 2025 ITP, spot loads appear in Future 2 as a resiliency condition; in the 2026 ITP, they're being folded into both futures.
These submissions feed into two planning scenarios.
- Future 1: the reference case. Existing agreements plus planned generation. Uses the base forecast as submitted.
- Future 2: Emerging technologies. Layers spot loads and higher EV adoption on top of the Future 1 base.
Total load projections depend on which future is used. In the latest 2025 Integrated Transmission Plan (ITP), base peak load in 2034 reaches 70 GW. Future 2 pushes the same horizon to approximately 83 GW.
Previews of the 2026 ITP go further: Future 1 reaches 91 GW by 2035, and Future 2 reaches 110 GW.
Just three years ago, growth rates in the 2023 ITP ranged from 0.5% to 2% annually. Since then, large loads requesting interconnection have pushed each successive forecast materially higher. The latest 2025 ITP Future 2 implies approximately 5% compound annual growth.
What is driving the growth in load?
Spot loads are the dominant source of incremental growth. Stakeholders submitted approximately 11 GW of new large loads during the 2025 ITP scoping process. In the 2026 ITP, this figure has jumped to 30 GW.
SPP now treats large load growth as a baseline planning assumption rather than an upside scenario. In the 2025 ITP, spot loads appeared only in Future 2 as a resiliency condition. The 2026 ITP includes them in both futures.
These loads are not limited to data centers. The ITP report also identifies oil and gas electrification, manufacturing, and industrial production as significant contributors. SPP's spot load pipeline spans multiple sectors, unlike PJM, where data centers dominate.
These large loads pose to add flat, 24/7 demand, raising base load year-round, instead of sharpening the summer peak specifically.
However, unlike PJM, SPP does not filter spot loads through a materialization framework.
PJM applies a 50% non-firm discount with 70% utilization and a 36-month ramp. SPP models the full pipeline.
The gap between pipeline submissions and what actually materializes is the single biggest analytical uncertainty in the ISO’s forecast.
Where is load growth concentrated across SPP?
Growth is highly uneven across SPP's footprint. 8 of 17 planning areas show peak demand growth exceeding 20% between the 2023 and 2026 ITP 10-year forecasts. Two planning areas, SPS and OPPD, have seen more than a 100% increase in expected load growth.
In absolute terms, SPS dominates. Load in the SPS area grew from approximately 4.7 GW to 11.5 GW across the past three ITP cycles, a 2.5x increase. Under Future 2, SPS's share of total system load rises to 20.8%, up from 11.4% historically.
Both SPS and SWEPCO function as transmission peninsulas with limited ties to the broader grid. The 2025 ITP notes that this limited transfer capability has already contributed to real-time load shed events. With approximately 1,500 MW of additional load expected in SWEPCO alone, the risk of localized voltage instability remains elevated.
This concentration drove SPP's recommendation for a 765 kV overlay through the region, with the first circuit needed by summer 2026 to prevent voltage collapse. Without it, the models show the southern New Mexico network cannot support load at projected levels.
At the state level, 7 of 15 states expect peak loads to grow by at least 20% over the 2025 ITP's eight-year horizon.
Why SPP’s forecasts are likely too high
SPP's headline forecast of 110 GW almost certainly overstates the peak load that will materialise by 2035. The 2025 ITP layers several compounding assumptions - unfiltered spot loads, no timeline discounting, and extreme weather stress conditions - each of which inflates the number.
Strip any one of them out, and the forecast drops materially.
That does not mean load growth isn't real. Spot loads are being actively recategorized as firm loads for SPP's future.
In SWEPCO, 500 MW of spot load in 2025 ITP was converted to firm in 2026 ITP, with another 1,000 MW described as “high confidence”.
Base planning assumptions have already risen from 59 to 75 GW across ITP cycles. These uncertainties apply to the remaining spot load pipeline that sits on top of that.
Flexible battery capacity can support growth concentrated in southern SPP
Battery storage does not replace backbone transmission. But in zones where line upgrades face five-year lead times and load is arriving now, strategically sited BESS can absorb local peaks, reduce congestion, and bridge the gap until the 765 kV system is built.
For developers, this presents an opportunity to contract with large load customers and help expedite interconnection.
The first such deals are already emerging.
Three NextEra batteries in southern SPP have capacity contracts with Google and Oklahoma Municipal Power Authority. These contracts are bundled with existing wind projects to support flexible capacity needs arising from large data centers.
For NextEra, these contracts provide $8-10/kW in fixed monthly revenues. Developers can lean on such contracts as the foundation for accessing cheaper debt capital. Read our quarterly financing update to learn more about the current U.S. financing environment.
