The California Independent System Operator (CAL-ISO) reported on October 27 that gross benefits realized in the third quarter of this year from the western Energy Imbalance Market (EIM) totaled $12 million, bringing the cumulative benefits since the market’s launch to $33.41 million.
The western EIM – a real-time market that went live on November 1, 2014 – creates significant reliability and renewable integration benefits for ratepayers by sharing and economically dispatching a broad array of resources. ISO advanced market systems automatically balance supply and demand for electricity every 15 minutes, dispatching the lowest-cost resources every five minutes.
For the quarter, CAL-ISO stated, the greatest benefits were realized in July, at $5.69 million; followed by $3.32 million and $2.99 million for August and September, respectively. Interregional transfers reduced supply costs in one EIM balancing area to meet demand in another.
The Q3 benefit of $12 million was 18 percent higher than the previous quarter – reflecting the seasonal variation in system and market conditions, as summer temperatures peaked in the region.
In addition to the gains produced by interregional transfers, savings also were realized by avoiding curtailment of renewable resources in the ISO balancing area. The total avoided curtailment for Q3 was 828 megawatt-hours (MWh). This number did not match results for 2Q2015 because, with high prices in the ISO area, there were fewer transfers from the ISO to PacifiCorp.
CAL-ISO has several initiatives underway to further evolve the market as new entities participate. However, the independent system operator announced on October 29 that CAL-ISO and NV Energy are delaying the November 1 date for the Nevada-based utility to begin financially binding participation in the western Energy Imbalance Market (EIM).
The two companies maintain their readiness to proceed with full EIM participation while awaiting the final authorization to proceed from the Federal Energy Regulatory Commission (FERC).
NV Energy will be the second utility to participate in the EIM, following PacifiCorp’s official entry on November 1, 2014. Puget Sound Energy of Washington State and Arizona Public Service remain on-schedule to enter the EIM in October 2016.