The Biggest Battery in the World is Hanging on the Garage Wall

Consumers Looking for Climate Solutions and Energy Reliability Amidst Fires and Blackouts Turn to Battery Storage

Out of step with consumers, energy needs and climate change goals, California regulators consider utility industry proposals that would slow California’s globally significant solar-charged battery market

Sacramento, CA—A new study released today by the California Solar and Storage Association (CALSSA) today showed California consumers added 300 megawatts (MW) of battery storage capacity since August 2020 as residents and businesses prepare against an unreliable energy grid and seek ways to reduce air pollution locally. More than 32,000 California consumers added over 20 MW of battery storage per month over the past year, doubling the number of systems and increasing the distributed energy storage market 70%.

In the aggregate, distributed battery storage capacity is larger than any single utility-scale battery facility. By comparison, a recent expansion at California’s Monterey County Moss Landing facility brought its total capacity to 400 megawatts. News reports declared it the largest battery in the world. Yet, that system is short of California’s distributed battery storage capacity which now stands at 721 MW.  

The market for distributed batteries is diverse, involving more than 62,000 installations at homes and businesses throughout the state, including targeted efforts in environmental justice communities hit hard by rolling blackouts. California consumers prefer to charge their batteries with solar photovoltaic modules located on the same property, with an estimated 70% of the battery inventory solar charged (link to memo). 

“In the face of dangerous fires and stressful blackouts, consumers are taking matters into their own hands rather than trusting big utilities like PG&E to look out for them,” said Bernadette Del Chiaro, executive director of CALSSA. “Consumers can either choose fossil fuel backup generators or they can choose pollution-free and more reliable solar charged batteries, and an increasing number of consumers are looking to the sun for their energy solutions. This is a smart move for the individual that also ends up benefiting everyone by taking pressure off the grid and helping to make it more climate resilient.” 

More consumers are turning to battery storage, paired with rooftop solar, as their best defense against an unsafe and unreliable energy grid. Battery storage is considered by many to be a superior energy reliability strategy compared to diesel fuel generators which are loud, expensive to operate, and contribute to pollution and climate change-causing emissions. 

In addition, the availability of tens of thousands of individual batteries also provides greater reliability. If one battery malfunctions or goes down, the rest of the batteries are unaffected and remain online. This is not the case with utility-scale battery systems where the entire facility is taken offline when something goes wrong with even one small unit within, as has happened recently at the Moss Landing facility. 

“I live in an area frequently hit by power shut offs,” said Marquis Smith, a resident of American Canyon in Napa County. “Thanks to my solar and battery system, I’m known in the neighborhood as the guy with juice. I often toss an extension cord over the fence to help my neighbors get a charge during frequent blackouts.” 

Another season of blackouts and devastating fires reminds us not only of the need to curb the impacts of climate change, but also the importance of developing an energy grid that is safe, reliable, and resilient. 

Rooftop solar and battery storage are ready to be part of the solution. During the last year’s heatwave in August 2020, California’s energy regulators called upon the solar and storage industry to work with customers to voluntarily modify charging and discharging of their batteries in line with the grid’s greatest needs. Many customers complied, without compensation, to help save the day as highlighted in a joint letter to Governor Newsom. Yet, despite this, California’s investor-owned utilities are lobbying the state agency that regulates them, the California Public Utilities Commission (CPUC), to make solar charged batteries more expensive. A move that would dramatically shrink the market. 

“Our government leaders should be doing more to help the average person invest in solar and batteries to achieve our clean energy goals and build a safer, more reliable electric grid,” said Del Chiaro. “That is why it is dumbfounding to see the California Public Utilities Commission considering proposals from big utilities that would make solar prohibitively expensive and halt our promising clean energy growth in the process.” 

The CPUC is moving towards a critical decision that will determine whether rooftop solar, along with battery storage, continues to grow or whether the state puts the brakes on this form of popular clean energy. At issue is the future of net metering, which makes solar-charged batteries more affordable for everyday consumers by blocking discriminatory fees and compensating people for the excess energy they produce and share with their neighbors, including energy from batteries that can be discharged in the evening. 

Currently 1.2 million consumers use net metering, including thousands of public schools and apartment buildings. The policy is responsible for dramatically growing rooftop solar in California by making it more affordable to working- and middle-class households, which now represent nearly half the solar market. Net metering can also drive the adoption of solar paired with energy storage if properly structured to create economies of scale and a glide path to growth. Proposals submitted by California’s investor-owned utilities would gut the market for solar as well as solar charged batteries by reducing the credit solar consumers receive for the excess energy they produce and adding a $65 to $90 monthly solar penalty fee to their energy bills. 

A draft decision from the presiding judge at the CPUC is expected in early December.