Hundreds of thousands of homes in California lost power early on Wednesday as windy, dry weather increased the risk of fire, prompting the electric utility, PG&E, to shut down the grid to avoid any chance of the type of power-line accident that sparked the deadly wildfire in the small town of Paradise less than a year ago. It may take days for the power to come back on. But at some homes, solar and battery storage systems are keeping the lights on.
“Between the solar and the batteries, we could go on indefinitely as long as there’s some sun,” says architect Richard Schuh, who lives and works in the hills north of the town of Sonoma in an area without power. He and his wife now rely on a Tesla Powerwall connected to the solar panels on their roof. They decided to install the system after a major fire in 2017 blazed through their property, sparing their house but taking out power for three weeks.
“We had solar the whole time, but the solar was shut down because it’s connected to the grid,” he says. “So we weren’t able to use that even though it was still generating power.” They installed the battery earlier this year. When the utility warns that it may need to cut off power, the battery gets an alert so that it can automatically fully charge in advance. When the grid is down, the system operates independently, continuing to store power from the house’s solar panels.
“When the grid goes down, everything shuts down with it,” says Anne Hoskins, chief policy officer at Sunrun, a company that sells solar power systems and home batteries. “But when you have the batteries and the solar panels and the inverters, we’re able to essentially create a little microgrid for the house so that the house can continue to receive solar power during the day. And then solar power can be stored in the battery as well, that could then be used in the evening when it’s dark.”
When the grid operates normally, batteries manage how solar panels send power back into the grid, helping provide power when demand peaks. That means that a homeowner can save money on electric bills since the utility charges more when demand is highest. “It provides value, not just during an outage but actually allows you to take advantage of off-peak electricity rates all year round,” says Dan Lashof, a homeowner in Berkeley who uses a Powerwall battery with a home solar system.
As more people install batteries, that can also help reduce the risk of fire by easing stress on transmission lines. “The more people that we can get engaged in helping to provide energy at what we call the ‘edge of the grid,’ the less has to be transported through forest areas and over system distribution and transmission lines that we know are really in need of repair,” Hoskins says.read more