CAISO board moves to integrate storage resources and improve reliability for fall 2021

by Paul Ciampoli
APPA News Director
November 23, 2020

The California Independent System Operator (ISO) Board of Governors last week adopted market tools that it said will help integrate new battery storage resources and improve overall reliability for next fall.

The board’s approval of Hybrid Resources Phase 2 was expedited to accommodate more than 1,500 megawatts of storage capacity expected to connect to the grid by the end of next year.

The storage capacity is part of California’s procurement goal of 3,300 MW of battery resources by 2023 to help replace retiring fossil fuel generation.

The proposal adopted by the board:

• Allows hybrid storage resources to provide energy and ancillary services to help maintain the reliability of the transmission system. Additionally, the hybrid resource owners will use a newly developed tool that gives grid operators visibility into the amount of energy these hybrid energy resources can provide in real-time;
• Expands the functionality of co-located batteries by allowing such storage resources to provide grid reliability services; and
• Requires both hybrid and co-located storage resources to provide the battery’s maximum output data to help with forecasting and improve operators’ visibility into the resource during the day.

In related news, the Federal Energy Regulatory Commission on Nov. 19 adopted CAISO’s Hybrid Resources Phase 1 tariff.

FERC’s order responded to a September filing made by the grid operator. In that filing, CAISO proposed revisions to its open access transmission tariff regarding modeling separate resources that are co-located at a single generating facility, and data requirements for hybrid resources that include a wind or solar generation component. 

The Board of Governors approved the first phase of the Hybrid Resources proposal at its July 27 meeting.

Implementation of Phase 1 is scheduled for fall 2020.