How Solar and Batteries Could Help California Manage Fire-Prevention Grid Shutdowns

Sunrun wants solar-battery microgrids to be part of PG&E’s plan to mitigate what could be widespread blackouts geared to prevent fires.

As Pacific Gas & Electric and California regulators grapple with how to manage the potential for widespread fire-prevention grid shutdowns this summer, clean energy advocates are demanding a role for solar, energy storage and microgrids as part of the solution set. 

But, as with so much related to the state’s de-energization plans, there’s much uncertainty over how to balance two potentially competing imperatives: the need to move quickly to mitigate potential grid emergencies this coming summer, and the need to find long-term fire mitigation methods that also match the state’s clean energy goals.  

That’s one way to summarize the comments filed by solar provider Sunrun (PDF) earlier this month, asking the California Public Utilities Commission to “use behind-the-meter DERs, specifically solar and energy storage such as batteries, to mitigate the disruption to Californians caused by de-energization.” 

Sunrun’s comments are among the dozens filed by utilities, public agencies, industry groups and other stakeholders in the proceeding launched by the California Public Utilities Commission in December to restructure its de-energization rules for utilities. It’s one of several proceedings underway at the CPUC to deal with the aftermath of the deadly wildfire seasons of 2017 and 2018, including the potentially massive liabilities that led PG&E to file for bankruptcy protection last month. 

GTM has been covering the complex debate over de-energization policy, including PG&E’s decision against de-energizing power lines suspected of playing a role in starting the Camp Fire in November, and the threat by the federal judge overseeing PG&E’s probation for criminal convictions related to the 2010 San Bruno gas pipeline explosion to force a much more restrictive de-energization plan on the utility.

PG&E’s wildfire safety plan, submitted to the CPUC earlier in February, laid out an aggressive plan to expand its public-safety power shutoff program in ways that could open up the possibility of hundreds of thousands, or even millions, of customers being left without power during times of high fire risk. It also laid out plans for mitigating the impacts of these potential shutoffs, primarily focused on utility-side grid investments such as sensors and monitors to guide more accurate de-energization decisions, and grid sectionalization to reduce the scope of outages when they occur. 

But PG&E’s plan was lighter on the behind-the-meter opportunities to mitigate fire-prevention grid outages. Its most concrete plan for “resilience zones,” or grid interconnection hubs that can support fast deployment of backup generators in high-risk areas, along with the infrastructure to island key critical assets, is limited to a single pilot project at present. And while the utility raised the possibility of working with non-utility partners with distributed energy resources for continuous power during safety outages, or expanding resilience zones into “resilience microgrids,” it didn’t provide any specific plans on that front. 

“We were hoping that utilities would embrace these concepts more in their fire plans,” Anne Hoskins, chief policy officer for Sunrun, said in an interview. “Yes, we need to make sure that existing lines aren’t going to cause fires. That’s an essential role of utilities and the commission. But considering that all the signs appear to be pointing to this as a recurring problem — and given our understanding that one of the most effective ways of dealing with it, at least in the short term, is de-energization — we do have the technology to give people access to energy, and that’s distributed solar and storage.”

A solar-plus-storage solution

Sunrun’s filing makes a few direct suggestions for how the CPUC could insert clean energy alternatives into PG&E’s plan. On the subject of PG&E’s proposed resilience zone plan, which appears to call for mobile diesel or natural-gas-fired generators, Sunrun asks the CPUC to “direct PG&E to use only preferred resources for such temporary generation, rather than generators powered by diesel or other fossil fuels, and to acquire such resources through competitive procurement or a tariff.” It also noted that “there is no reason for these generation resources to be temporary; rather, technologies such as solar and battery systems can provide reliable power to critical loads during de-energization events, as well as benefit customers during normal conditions.” 

Sunrun also suggested several other paths the CPUC could take to encourage more solar-storage deployment in high fire risk areas. One existing funding stream is the state’s Self-Generation Incentive Program, which was reauthorized by the state legislature last year to spend about $830 million over the next five years, 75 percent of it directed at behind-the-meter storage. Sunrun suggests that the CPUC could modify its existing rules to “incentivize distributed energy storage systems in communities most susceptible to de-energization and disasters that may render the grid unsafe or unusable.” Similar incentives could be extended to vulnerable populations such as low-income or elderly customers, it noted. 

Sunrun also suggest the CPUC could explore its authority under a state law passed last year, SB 1339, that directs it to explore new rates, tariffs and interconnection standards and agreements to allow broader commercialization of microgrids. California’s Electric Program Investment Charge, which has directed hundreds of millions of dollars to energy research efforts and pilot projects including microgrids, could also be used to “demonstrate use cases for behind-the-meter solar, storage, and other DERs to keep the lights on, as well as explore innovative uses that enable neighbors to share power during emergencies and blackouts,” Sunrun wrote. 

More specifically, existing solar-storage customers “may have additional battery capacity and capabilities that may remain untapped and, with appropriate incentives, could be more fully utilized for the public benefit,” Sunrun wrote.  As Hoskins noted, Sunrun’s customer base in California includes many homes and businesses located in the expanded fire risk regions now targeted for possible de-energization by PG&E. “That’s one opportunity — looking at what it would take to augment what we have in place, and what incentives it would take for these customers to be engaged.” 

Hoskins acknowledged that the CPUC and California’s utilities have a challenging task ahead of them in implementing effective and safe fire mitigation plans for this summer, and that novel applications of solar-storage systems will have to come in an incremental fashion. “Realistically, the way this should happen should be through a number of pilots,” she said. 

But at the same time, Sunrun is “concerned” about utility plans to invest in infrastructure “just to connect generators. They should at least be making ready to connect something like solar.”