Western Energy Imbalance Market
Avista will enter the Western Energy Imbalance Market (EIM) administered by the California Independent System Operator (CAISO) in April 2022. The Western EIM began in November 2014, and currently has 14 committed utilities encompassing 70% of the load in the Western Interconnection. It is a real-time voluntary bulk power trading market, the first of its kind in the western United States. The EIM’s advanced market systems automatically calculates the lowest-cost energy profile and sends dispatch signals every 5 minutes to serve real-time customer demand across a wide geographic area. Participating utilities maintain control over their generation assets, and remain responsible for balancing generation and load requirements, while sharing market benefits.
Frequently Asked Questions
The EIM is a real-time energy balancing market that automatically dispatches the lowest-cost electric resources available over a large geographic area to meet utility customer needs while optimizing the use of renewable energy. By rebalancing supply and demand across a larger more diverse footprint and in a more economic manner, the western region can share generation resources, which drives customers costs lower and allows for the efficient dispatch of cleaner, more affordable energy resources.
We can integrate additional solar and wind resources up to the point where our current hydro and thermal generators run out of flexible ramping capacity, however we will need to carry large amounts of flexible reserves which is extremely inefficient and more costly than relying on the EIM to balance the variability of these resources.
Avista will be required to carry additional flexible reserves or purchase this capability from others at a higher price due to the lack of counterparty trading in the Real Time market. All EIM entities currently stop bilateral real time transaction 90 minutes prior to the operating hour.
Yes – all EIM participants maintain operational control over their generating resources, retain all their obligations as a balancing area, and must remain compliant with all regional and national reliability standards. For example, obligations to comply with standards, procuring ancillary services, physical scheduling rights and bilateral trades do not change with EIM participation.
Avista plans for market entry in the EIM in April of 2022.