Coal, Gas, Nuclear, Renewables

More Utilities to Join CAISO’s Energy Imbalance Market

By Editors of Power Engineering

Seven electricity providers in the western portions of the United States and Canada plan to join the California Independent System Operator’s western energy imbalance market through 2020, the Energy Information Administration reported.

The EIM allows for more frequent dispatch of electricity-generating resources in the region, and more member utilities will provide new opportunities for matching electricity supply and demand.

Unlike most markets, which dispatch generation hourly, CAISO trades electricity in 15-minute intervals and dispatches generating units every five minutes to balance supply and demand. This rapid responsiveness allows for better integration of wind and solar resources that can have frequent changes in generation.

The CAISO’s EIM was founded in the fall of 2014 with PacifiCorp, and now has participation from NV Energy, Arizona Public Service and Puget Sound Energy. The EIM now balances systems that supply 55 percent of electricity sales in the western grid of the continental United States. Powerex, a subsidiary of Canadian balancing authority BC Hydro, will be the first non-US entity to participate.