California’s grid batteries make 2021 splash. What a difference a year makes. According to California ISO (CAISO) data compiled by the Hitachi ABB Power Grids’ Velocity Suite research team, utility-scale battery storage systems are performing well in 2021. Just one year ago, in July 2020, the charge and discharge data from the state’s utility-scale batteries was barely a heartbeat. Flash forward to July 2021, and the curve derived from average hourly net energy shows a dramatically different story with most net charging occurring predominately between 7:00 AM and 4:00 PM PST – about the same time solar is ramped up across the market. Net discharging is occurring later, during the evening peak, from around 6:00 PM PST through the remainder of the day.
California ISO daily battery net energy by the hour
July 2021, MWh
July 2020, MWh
On July 27, 2021, during the two-hour period, between 7:00 PM and 9:00 PM, the average hourly discharge reached 1,022 MW. The average discharge for all days of the month during those two high-load hours was 645 MW. The highest average hourly discharge during the month was 1,135 MW on July 27, between 7:00 PM and 8:00 PM PST. The numbers are growing fast, already on August 7 (Saturday) 2021, the CAISO reported an average 5-minute discharge of 1,276 MW at 7:10 PM PST. These numbers are sure to continue upward as the year unwinds and several projects currently under construction enter service.
There are currently about 1,200 MW of operating battery systems in California with about 2,000 MW under construction or testing. There are approximately 4,000 MW of additional capacity expected online across the state by the end of 2024, this from data compiled by the Velocity Suite research team. Some of the largest projects to enter service during the past year include LS Power’s Gateway Energy Storage Project (250 MW/250 MWh), AES Corporation’s Alamitos Energy Center (100 MW/400 MWh), NextEra Energy’s Blythe Solar projects (250MW/1,000 MWh), Arevon Asset Management’s Saticoy battery energy storage project (100 MW/400 MWh) and the largest installation so far, Vistra Energy’s Moss Landing Energy Storage Facility (300 MW/1,200 MWh) facility. NextEra is on schedule for the Blythe and McCoy Energy Storage complex (523 MW/2,093 MWh) to be operational by the end of August. In addition, the Moss Landing project is on schedule to add an additional 100 MW/400 MWh facility this month.
One of the key drivers behind the rapid growth in battery storage is the federal Investment Tax Credit (ITC) that is currently available for solar plus storage hybrid projects. That could become even more attractive if legislation is passed to allow stand-alone battery storage projects to qualify for the ITC without being combined with solar. Today, across the U.S., there are roughly 2 GW of operating battery storage projects with nearly 11 GW in various stages of development – all scheduled for completion between now and the end of 2024.
Solving renewable energy’s greatest hurdle, intermittency, will take a large amount of storage capacity – both short-duration (hours) and long-duration (days). Maintaining a reliable power grid while continuing to grow solar and wind resources depends on successful storage project implementation. The future glows brightly for the current array of battery storage technologies and other, yet to be developed, electricity storage technologies. What a difference a year makes.