Ancillary services are grid reliability products that system operators procure alongside energy to keep the power system stable. Ancillary services cover second-to-second frequency corrections, backup power for when a generator trips offline, and ramp management as variable renewable output fluctuates. BESS deployments in MISO are well suited to participate in ancillary service markets given their ramp rates and flexible charging/discharging patters.

MISO operates five ancillary service products on its wholesale markets, distinct from other reliability services like black start and voltage support.

These five products form a hierarchy based on response speed: faster response means scarcer supply, stricter technical requirements, and higher prices. Only one, Regulation, generates meaningful BESS revenue.

The 2025 DA Regulation price average of $17.34/MWh was 59% above the 2023 baseline. Early 2026 data suggests further acceleration with DA Regulation prices in January 2026 averaging $27.88/MWh. For developers stress-testing MISO project economics, the ancillary services revenue stack sits almost entirely in Regulation.

Key takeaways

Regulation is the most bankable ancillary service in MISO for batteries, with DA prices rising 59% from $10.91/MWh (2023) to $17.34/MWh (2025).
The Spinning Reserve DA price is a distant second at $4.32/MWh. The Supplemental Reserve DA price averages about $1/MWh.
Real-Time (RT) Regulation peaked at $1,151/MWh on July 28, 2025. With the Value of Lost Load (VOLL), the ceiling price during a supply shortage, now tripled to $10,000/MWh, future scarcity events could increase prices.
MISO raised its Regulation procurement from 400 MW to 600 MW, extending the runway before the market reaches saturation. Dynamic requirements targeting 2026 could further expand volumes and price volatility during solar ramp hours.

Five ancillary services products, one that pays

MISO procures five reserve products with energy in both the day-ahead and real-time markets.

The key distinction between products is response speed. That hierarchy drives the price hierarchy. The table below summarizes each product, its response time, procurement volumes, and clearing prices.

Regulation is the fastest and highest-paying product. Awarded resources follow Automatic Generation Control (AGC) signals, adjusting output every four seconds. MISO procures 600 MW. At current DA prices, Regulation is the most lucrative revenue stream in most hours.

Spinning Reserves requirs actively generating resources that can ramp within 10 minutes. At a DA average of $4.32/MWh in 2025, Spinning Reserves offer a secondary revenue stream when Regulation capacity is already committed. The requirement ranges from 900 MW in non-ramping hours to 1,200 MW in ramping hours, sized to cover the loss of the largest generator on the system.

The remaining three products pay too little to anchor a BESS revenue case:

Supplemental Reserve: covers the remainder of contingency needs (1,110 MW requirement), but clears at just $1.01/MWh DA
Short-Term Reserve (STR): introduced in 2021 to address the 30-minute window. The requirement is dynamic, sized at 1.5 times the largest contingency, with similarly low clearing prices
Ramp Capability: introduced in 2016 to manage net load variability. Resources are paid to hold back capacity to cover expected swings in wind, solar, and demand over the next 10 minutes.

Regulation deploys continuously via AGC. Reserves deploy only after a contingency event. Those deployments are rare but produce extreme price spikes.

How does MISO set requirements for ancillary services?

Reserve requirements follow North American Electric Reliability Corporation (NERC) standards, sized to cover the loss of the largest single resource:

Spinning Reserve: at least half of the total contingency
Supplemental Reserve: the remainder of the total contingency
Short-Term Reserve: an additional 30-minute back-up of the total contingency

These requirements are nested: a resource qualified for a faster reserve product also counts toward slower reserve needs. Spinning Reserve capacity can fill Supplemental Reserve slots, because a synchronized unit can do everything an offline unit can. However, Regulation capacity cannot count toward Spinning or Supplemental needs.

MISO sets Regulation at 600 MW based on system variability. Unlike NYISO, where requirements fluctuate by hour and season, MISO applies a static value around the clock. This is expected to change in 2026.

How does MISO clear prices for ancillary services?

All five products clear alongside energy in a single optimization. MISO's market software finds the lowest-cost mix of energy and reserves together. When reserves run short, MISO's shortage pricing schedule (officially the Operating Reserve Demand Curve, or ORDC) increases prices based on how far supply has fallen below target levels.

At the top of that schedule sits the Value of Lost Load (VOLL): the dollar amount regulators assign to each megawatt-hour of electricity that goes unserved. In practice, VOLL is the maximum price the market can reach during a shortage.

Two structural changes are lifting Regulation prices

The 2025 increase was not a one-off. Two policy changes raised the price floor.

First, MISO raised its Regulation requirement from 400 MW to 600 MW. H2 2024 DA Regulation prices averaged $13.31/MWh, 32% higher than H1's $10.11/MWh.

Second, MISO nearly tripled VOLL from $3,500/MWh to $10,000/MWh effective September 2025, a level unchanged since 2007. The previous shortage pricing schedule had two flat steps at $1,100/MWh and $2,100/MWh. The new schedule lets prices rise smoothly toward the $10,000/MWh ceiling.

November 2025 averaged $19.65/MWh day-ahead, the highest full month since 2023. January 2026 reached $27.88/MWh during a winter cold snap that tightened reserves. February moderated to $18.04/MWh. The two-month average of $23.59/MWh reflects the new VOLL ceiling and seasonal volatility, not a permanent plateau.

Real-time Regulation consistently clears above day-ahead. In 2025, RT averaged $20.46/MWh versus $17.34/MWh DA, an 18% premium. The gap widened as the year progressed:

2025 full year: RT $20.46/MWh vs DA $17.34/MWh (18% premium)
March 2025 (widest spread): RT $22.78/MWh vs DA $15.84/MWh
February 2026: RT $23.07/MWh vs DA $17.91/MWh

For BESS operators bidding day-ahead, the persistent RT premium suggests real-time exposure captures additional value, but with higher volatility risk.

Late fall and winter produce higher regulation prices. Spring runs lower. Regulation is most competitive with arbitrage during shoulder months, when energy spreads compress.

Daily data captures what monthly averages smooth over. On July 28, 2025, RT Regulation averaged $79.62/MWh for the day, more than 4x the monthly average. The hourly peak reached $1,151/MWh in HE19. This was the last major scarcity signal before the September 2025 VOLL update. Under the new $10,000/MWh ceiling, similar tightness could produce prices several times higher.

How does Regulation compare across ISOs?

PJM consolidated its two regulation signals into a single bidirectional product in October 2025, with a planned split into Regulation Up and Regulation Down in October 2026. MISO has always used a single Regulation product cleared through co-optimization with energy.

In contrast to NYISO, where reserve requirements are also zone dependent, MISO’s regulation prices have limited locational differentiation.

For BESS operators, MISO's single-product design simplifies bidding compared to PJM's upcoming two-product split, and the system-wide market means locational basis risk is minimal.

What do BESS operators need to know?

Batteries became eligible for all five products in mid-2022 under FERC Order 841. In practice, eligibility comes with constraints:

Synchronization: Units must be online to provide Spinning Reserve as MISO's clearing software cannot process offline storage offers.
Interconnection Agreement charging limitations: Interconnection agreements can restrict when a battery charges. A stakeholder initiative (PAC-2024-3) is working to remove outdated restrictions.
State-of-charge: MISO leaves SoC management to the asset owner, unlike NYISO which offers an ISO-managed option. Operators must balance Regulation headroom against energy spreads.

The growing renewable fleet is also increasing system variability, which in turn drives more frequent reserve shortages. For batteries, this compounds: more Regulation MW to sell, at higher prices, with more frequent scarcity spikes.