ERCOT’s newest ancillary market (ECRS) started up in June 2023. This change cut the amount of non-spin which ERCOT procured in half, while creating a new market of roughly equal size, essentially splitting what was previously the non-spin market into two different flavors of longer-duration AS products, with ECRS requiring faster start up times but only 2 hours of energy output, while non-spin requires 4 hours. See Updates on ECRS for more details.

While ECRS enjoyed some large premiums over other markets when it was first introduced, it has actually been priced at a discount to comparable markets (RRS and RegUp) consistently since October 2024

Figure 1 – Average monthly ERCOT AS prices by market (excluding scarcity events)