4-hour batteries in SPP South are projected to earn $188/kW-year in 2027, driven by tight capacity reserve margins and unsaturated Regulation products.

Revenues fall to $120/kW-year by 2030 as these streams stabilize, plateauing at $66/kW-year through to 2050.

But what market fundamentals are driving this revenue?

Modo Energy's SPP BESS Revenue forecast is live

Users can run two forecasts for free in the Forecast Library.

Read the SPP methodology to learn more about the forecast, or book a demo to walk through your results with our modeling team.

In the next decade, SPP anticipates 20 GW of load growth from oil and gas electrification in the Permian Basin and an influx of AI-compute data centers. Retiring coal generators remove 7 GW during the same period.

The RTO is projecting potential loss of load events if transmission upgrades and buildout cannot keep pace with new load applications.

The most economical way for SPP to meet this rise in demand is through a combination of wind, natural gas, and, for the first time, solar and batteries.

Projection indicate SPP will add 37 GW of solar and 26 GW of wind by 2035. Battery projects are moving in waves through the streamlined Surplus and CPP connection queues to firm this capacity.

By 2030, battery storage could stand at 19 GW, from less than 1 GW today

Read on to understand what’s driving battery revenues in the latest release of Modo Energy’s SPP BESS Revenue Forecast.

​​Navigate to the sections below

• Load Growth
• Buildout and retirements
• Generation mix
• Price spreads and ATCs
• Resource Adequacy capacity prices
• Ancillary Service saturation
• Revenue projections

SPP peak load rises to 102 GW by 2050

SPP’s 2026 Integrated Transmission Plan forecasts summer peak load rising from a historical high of 56 GW to 91 GW by 2035 under its Future 1 scenario.

Projecting this forward, summer peak load should grow to 102 GW by 2050. Winter remains more muted, with the peak rising from 51 GW to 80 GW by 2050.

The bulk of this growth comes from spot loads: large single-point connections for industrial and data-center customers.

In 2025, developers requested 30 GW for these new large loads, up from 11 GW a year earlier.

43% of spot loads come from oil and gas electrification around the Permian Basin.

The next major source, and the influx in recent years, is from data centers.

Submissions from Transmission Operators show that growth is fastest in the SPS utility territory.

This expected growth is intractable with the pace of planned network upgrades, and SPP has warned of potential loss of load in the southwest.

How fast load materializes depends on how it connects to the grid, and the RTO’s new large load interconnection policy will help clear part of the bottleneck.

HILLGA delays observed demand from spot load growth by five years

On January 14, 2026, FERC approved HILLGA as one of SPP's pathways for connecting High-Impact Large Loads (HILLs): spot loads requesting 50 MW or more at a single point.

Rather than waiting on network upgrades, HILLs pair with co-located generators. They take contracted service for their first five years before transitioning to firm grid supply.

This bring-your-own-generation paradigm allows spot loads to expedite study timelines and come online, while keeping grid-observed peak load low while transmission builds out.

HILLGA is expected to delay up to 5.2 GW of observed load growth for five years to prevent loss of load in constrained regions such as SPS.

Coal retirements make way for 107 GW of renewables and natural gas by 2035

Utilities will lean on batteries, solar, wind, and natural gas as the most economical way to meet load growth.

In total, SPP sees 107 GW of new capacity arrive by 2035. Roughly 50 GW connects in 2026-2030, with another 57 GW deployed in 2031-2035. This pace halves to 20-32 GW every five years through to 2050.

Coal makes up 20% of the installed capacity in SPP today.

Over the coming decade, up to 7 GW of this capacity is scheduled to retire. An additional 8 GW of aging units will retire by 2050.

Natural gas helps fill this firm-capacity gap to meet load growth expectations.

SPP’s Expedited Resource Adequacy Study (ERAS) is fast-tracking 9.4 GW of firm natural gas capacity. These utility-backed projects plan to begin operating in 2029-2030.

Gas additions total 23 GW by 2035 and peak at 16 GW in 2031-2035, then continue at 3-7 GW per block for roughly 40 GW over the horizon to 2050.

This front-loaded buildout to match spot load additions extends to renewables.

Wind has been the dominant source of new generation in SPP for the past two decades.

The RTO lies over the Great Plains wind belt, which has the strongest onshore wind potential in the US. High capacity factors have historically made wind the economic choice.

Transmission corridors across the East-West wind-to-load split have cemented that pattern, allowing installed wind to grow tenfold from 3 GW to 34 GW.

The next decade will be defined by solar growth.

Solar is expected to add roughly 37 GW by 2035, accompanied by an additional 26 GW of wind.

Much like ERCOT, this influx of renewables is not the result of state-level RPS or carbon targets, but pure resource potential and favorable economics facilitated by federal tax credits.

Batteries arrive to firm up this capacity. Storage arrives in a wave of roughly 18 GW between 2026 and 2030.

That timing reflects the near-term interconnection queue alongside the tightening capacity balance. As planning-reserve margins bind and capacity prices climb, storage arrives as firm capacity alongside natural gas.

SPP’s Surplus Interconnection Queue has already provided a streamlined pathway for these early projects to use existing grid connections, boosting the load-carrying potential of intermittent renewables

The net effect is a decisive shift away from coal base load toward a system built on renewables, storage, and flexible gas.

Solar bends the SPP summer price curve into twin peaks

Over the forecast horizon, SPP's generation mix shifts from coal toward solar, wind, natural gas, and batteries.

Solar's share of total generation rises from around 1% in 2026 to 14% by 2035 and 21% by 2050, while coal falls from 29% to under 2%.

Wind, already the region's largest source at roughly 36%, holds its lead; the new dynamic comes from solar and the batteries built alongside it.

That build-out reshapes the average day. By 2050, solar is expected to peak near 35 GW at midday and fall to under 4 GW by early evening.

Gas plants ramp to meet the evening peak, rising from about 20 GW at midday to 27 GW after sunset.

Batteries charge during the midday solar surplus and discharge into the evening, reaching roughly 9 GW at the peak.

How does this impact price spreads?

The rise in 24/7 demand is expected to result in higher run hours for gas generators throughout the day.

With gas setting the price through more hours of the day, the price curve rises

At the same time, solar begins to depress midday net load.

The net effect up to 2035 is an inversion of SPP's summer price curve.

The existing late-afternoon price peak diminishes as the profile pivots from a single peak today to an evening-led, double-peaked day.