SPP’s Resource Adequacy (RA) program requires utilities to show they own or have contracted with enough generating capacity to meet peak demand for the following year.

In the summer of 2025, 58 GW (85%) of this capacity came from utilities’ own generators, while the remaining 9.8 GW (15%) was procured from Independent Power Producers.

For these private generators, RA contracts provide steady, de-risked payments that form the foundation for future revenues. The fixed-income stream ensures projects can pay back any debt-service charges on a loan. That makes it easier for them to secure capital to begin construction.

Continue reading this guide on SPP’s Resource Adequacy market to learn who the biggest customers are, how much you can expect to earn, and what you need to do to secure a contract.

Key takeaways

• SPP does not run a centralized capacity market auction. Generators bid for contracts with any of the market’s 64 utility companies.
• Batteries are accredited to sell 24-100% of their nameplate capacity, with higher proportions for 6+ hour batteries in the Summer Resource Adequacy season.
• Historically RA contracts have paid $2-3/kW-month, but this is expected to rise as deficiency penalties increase and Reserve Margins tighten.

​Updated 8th April 2026: A previous version of this article stated Resource Adequacy contracts pay $2-3/kW. It has been changed to $3-5/kW, in line with more recent analyses on the value of capacity contracts in SPP.

1. Who do generators sell their capacity to?

SPP has no centralized capacity market auction. Generators contract directly with any of the 64 utilities and energy suppliers, known as Load Responsible Entities (LREs).

These LREs fall into four groups:

1. Investor-owned utilities: Large, for-profit utilities. They own most generation and transmission in SPP - and buy the most RA capacity.
2. Cooperative utilities: Non-profit utilities primarily serving rural areas.
3. Municipal utilities: Public utilities serving residents within a city.
4. Public Power Agencies: Government-owned utilities that provide services at the city or regional level.

Investor-Owned Utilities serve 58% of the load in SPP, and buy 49% of the capacity procured in the bilateral Resource Adequacy market.

But despite procuring the most capacity, Investor-Owned Utilities account for only five of the top ten buyers in the market. Utilities with lower load requirements tend to own less generation, and buy a larger proportion of their RA requirement from private generators.

Western Farmers Energy Services, for example, purchased 42% (960 MW) of its RA requirement from Independent Power Producers, making it one of the top five customers for capacity in 2025.

2. How much capacity can a battery sell?

Generators can only sell up to their accredited nameplate capacity for Resource Adequacy.

For batteries, the proportion of their nameplate capacity that is accredited is based on two criteria:

1. Four-hour minimum: Each battery must be capable of supplying its power for at least four continuous hours. Shorter-duration systems are derated to a four-hour equivalent (e.g., two-hour → 50% of nameplate).
2. ELCC accreditation factor: rated power are then adjusted by an accreditation factor set in SPP’s annual Effective Load-Carrying Capability (ELCC) study. Factors vary by duration and season.

Multiplying a battery’s four-hour-adjusted nameplate rated power with their duration’s ELCC factor for the season gives the accredited capacity they are allowed to sell.

In 2026, the only batteries qualified to provide 100% of their nameplate capacity were eight-hour resources in the summer.

Why are battery capacity accreditations lower in the Winter?

A battery’s ELCC accreditation factor depends on how ‘reliable’ its capacity is during the most supply-constrained times of the season.

In the winter, loss-of-load scenarios are defined by shortfalls in wind generation and cold snaps that cause outages at gas and coal plants. Load is driven by heating, which produces long plateaued peaks rather than spikes.

These constraints can last several hours to days at a time. The capacity provided by duration-limited resources (i.e., energy storage) does not help resolve these constraints and is derated accordingly.

Compare this to the summer, where loss-of-load scenarios are caused by evening spikes in net load. Fast-acting, duration-limited generators like batteries can quickly respond to meet this need, and so their ELCC factor is higher.

ELCC values change year-to-year, and payouts are defined around them

Capacity contracts pay for the accredited capacity a generator agrees to provide. If future studies reduce the generator’s accredited capacity, the contract will specify how this is accounted for. ​

3. How much do Resource Adequacy contracts pay?

​Resource Adequacy contract prices have historically hovered around $3-5/kW-month, but payments are forecast to increase in the next few years, for three reasons.

Firstly, the penalty price to utilities for being deficient in RA capacity is set to rise. These penalties form the ceiling for Resource Adequacy payments, since rationally, utilities would only pay for RA capacity up to what it would cost them to remain deficient.