The California Independent System Operator's (CAISO) board of governors has approved the design framework for an energy imbalance market (EIM), which CAISO says will allow western grid operators to voluntarily participate in a real-time energy market that enhances grid reliability and responsiveness, integrates renewable power, and saves wholesale energy costs.
‘EIM marks a step forward in the West to more ably manage current complexities as the electric industry undergoes transformative changes to create a significantly cleaner energy network that enhances the utilization of renewables,’ says CAISO Board Chair Bob Foster.
‘By leveraging the ISO's real-time market, a broad array of resources can be shared and economically dispatched,’ he adds. ‘This strengthens grid reliability through enhanced real-time visibility across neighboring grids while matching energy needs with the lowest-cost resources.’
According to the system operator, its first EIM partner, PacifiCorp, has been working with the CAISO to prepare for implementation of the market, which is expected to go live on Oct. 1, 2014.
Significant increases in the amount of wind and solar power in recent years require grid operators to hold additional flexible generation in reserve to account for the variability of renewable resources, which are dependent on weather conditions, the CAISO notes. Without an EIM, operators generally must rely on generation assets within their balancing authority for any last-minute balancing.
The CAISO says the EIM includes only its real-time market and not its day-ahead market. Costs between balancing authorities are allocated according to cost-causation principles, and EIM balancing authorities still maintain all the operational responsibilities for serving their customers and maintaining reliability in their areas, the system operator adds.