By Sergio Duenas, Lily Backer, and Melanie Davidson
The California Independent System Operator (CAISO) is making history this summer by integrating thousands of megawatts of new energy storage resources. In the midst of this exciting milestone, storage and grid operators are preparing for the challenges of a potentially very hot and dry season.
Of the new resource capacity coming online, 1,493 MW is from battery energy storage systems (BESS) and will coming online by September 1, 2021.
To best understand the upcoming challenges and determine how storage providers can support reliability under challenging conditions in California, CESA Executive Director Alex Morris sat down with Mark Rothleder, Senior Vice President and Chief Operating Officer at CAISO for a conversation titled, Getting Summer-Ready with CAISO.
Summer 2020 was historically difficult for California’s electric sector. In mid-August, extreme heat caused spikes in electricity demand on the grid, and California struggled to meet these needs due to a confluence of resource outages and scheduling issues. This resulted in the CAISO initiating rolling outages for the first time in 20 years in the state on August 14 and 15, 2020.
While the outlook for 2021 grid conditions is better than last year, the anticipated hot and dry weather ahead could pose risks for a second consecutive summer of rotating outages for some or all of the following reasons:
The CAISO anticipates that weather events such as extreme heat or subpar solar conditions will cause a 2.5 GW (or 5%) increase in demand on the grid, relative to 2020. These demand conditions and weather forecasts may place continued and reliable operation of the grid at risk. Moreover, increased heat could increase the likelihood of wildfires across California, augmenting the chance of outages.
California had its second consecutive year of below normal precipitation. As a result, statewide snow water content is lower than 2020. This has resulted in California’s major reservoir storage levels being at 70% of average by April 2021 (compared to 101% of average in April 2020), significantly reducing hydroelectric power resources due to low water flow.
While California is a net exporter of energy across the year, the state benefits greatly from imports during hours with the tightest supply. The CAISO performed a study to evaluate the grid’s vulnerability under various peak conditions, particularly when energy imports are limited. Their analysis revealed that California’s grid could be at risk in the event of a widespread heat wave if neighboring states are also experiencing extreme weather and peak demands, limiting their ability to support.
The challenges mentioned above have pushed agencies and stakeholders to consider reforms to the planning and reliability process of the state, particularly within the realms of interconnection and resource adequacy. While these reforms will be essential in the future, the CAISO has highlighted several high-impact, near-term actions the storage community can take on to help maintain reliability on California’s clean grid this summer:
2021 will be the biggest year for energy storage deployment to date, placing California’s energy storage industry in the spotlight. The CAISO is expecting 3,961 MW of additional capacity to become readily accessible by September 1 – of this total, 1,493 MW will come from battery energy storage resources. Meeting commercial operation dates is critical to supporting reliability for Californians this summer. Showing up is the first step to demonstrating the viability of storage as a mainstream solution!
Responsiveness of the storage community to CAISO alerts and directives is essential. Exceptional dispatches and requirements to maintain a state-of-charge can pop up on days with insufficient supply; the storage industry should pay close attention and work to keep the lights on!
Ultimately, each individual has the power to help mitigate systemwide risks. Being a conscious consumer of electricity and planning activities mindfully to support the grid can lower the likelihood of insufficiency in particularly tight periods.