My turn: Here’s how rooftop solar can combat wildfires

 By Audrey Lee

Audrey Lee is vice president for energy services, Sunrun, based in San Francisco, with services in 23 states plus Washington, D.C., and Puerto Rico. audrey.lee@sunrun.com. She wrote this commentary for CALmatters.

U.S. District Court Judge William Alsup recently issued an unprecedented directive to Pacific Gas & Electric: Inspect its entire electric grid in the coming months and turn off power during fire-prone weather if its equipment has not been deemed safe for those conditions.

After the terrible losses caused by wildfires in recent years, this dramatic turn of events portends greater challenges to utilities in the face of a changing climate.

The Fourth National Climate Assessment reports that climate change and extreme weather events are going to make power disruptions and related wildfires even more common.

Californians deserve real solutions to reduce fire risk while meeting their energy needs. PG&E, other utilities, and the rooftop solar industry should partner to design wildfire mitigation plans that truly protect communities and address the concerns identified by state residents, policymakers, advocates, and the courts.

Local solar power paired with batteries can provide reliable energy and keep electricity running for communities in need, particularly at times when a power line needs to be turned off for safety reasons. This technology might also reduce the chances of electric sparks on overhead lines, which could result in dangerous wildfires.

Electrical lines can only safely carry a certain amount of power without getting too hot. When an electric line heats up with too much energy running through it, the line can sag and drop closer to potential hazards.

Currently, utilities can manage higher power flows for a short time to carry out limited repairs without transmission and distribution lines reaching extreme temperatures, but it may not be enough to handle increased wildfires.

If communities were to deploy more local solar and batteries, we could reduce the amount of power flowing through electricity lines, and  coordinate with utilities in real time, leading to an improved scenario for utilities to carry out maintenance, reroute power in case of problems, and ensure overall safety of fire-prone communities.

I have been working to promote energy innovation for decades, first with the U.S. Department of Energy, then at the California Public Utilities Commission, and now as the head of Energy Services at Sunrun.

Let me paint a picture of how this could work.

Consider a community of 500 homes, each using about 5 kilowatts of power, which is roughly the profile of a significant number of homes in fire-prone areas in California.

All these homes are currently connected to the wider network by a single electricity line. For a small community such as this, as few as five to 10 houses with rooftop solar and batteries could assist in reducing the power transported through the electricity line, thus maintaining the power at the required level for safe conditions during times of high demand.

Even in the case that this community were to require more energy and the electricity line supporting it reaches 100 percent capacity, this community would only need 50 to 100 homes with rooftop solar and storage to return to safe conditions.

Naturally, local solar and batteries  are more useful as more homes have them. But the minimum threshold to be valuable to engineers can be as low as a handful of customers, depending on how the electricity system in that area has been designed and built, as well as the needs of the supported community.

Home solar and batteries can provide for more resilient energy solutions in high-risk fire areas serviced by electric lines. More importantly, they can help reduce or even prevent power outages for homes, businesses, and other critical facilities.

We have a short period of time until the next fire season hits us. Californians are demanding better solutions from their utilities, now.

Sustainable business models and partnerships with solar leaders looking to protect fire-prone communities are a start. Let’s use this opportunity to come together—state leaders, regulators, local policymakers, the rooftop solar industry and utilities—to swiftly bring more solar and batteries to the communities that need them when it matters most.