Most homes running on solar would still lose power if San Diego Gas and Electric shuts off parts of the grid during Hurricane Hilary.
SDG&E spokesman Anthony Wagner confirmed late Friday that the utility has no plans to shut down the power – called a public safety power shutoff. But if conditions necessitated a power shut off, most solar systems can’t power homes and businesses on their own.
And that’s for safety reasons.
“In case of an unplanned outage, standard grid-connected solar systems are programmed to switch off to prevent unexpected energy from being sent to the power line as it is repaired,” Wagner wrote in an email.
So, rooftop solar by itself is a dud in grid shutdowns, that is, unless it’s also paired with a battery.
Rooftop solar works like this: When the sun’s rays convert to electricity through the photovoltaic cells of a solar panel, the energy is instantly converted into electricity. And while San Diegans have more rooftop solar than any other part of the state, most of those panels are still connected to the larger statewide energy grid that almost everyone shares.
Some solar systems can “island” during an outage or continue to provide power to some or all home appliances – but solar customers should check with their contractor to uncover this capability.
A grid-connected solar system is considered the cheapest form of rooftop solar. And it can also be lucrative. Solar owners still connected to the grid benefit from selling excess solar energy a home or car doesn’t need back to the power grid. That’s called net energy metering. Almost 90 percent of solar owners are participating in that program, according to the California Public Utilities Commission.
Solar customers can go off-grid entirely but that usually requires adding batteries large enough to power a home through the night or on cloudy days. Batteries of that kind cost thousands of dollars. Most are made with lithium and other metals that are rare and expensive to mine.
Hurricane Hilary’s core should move toward southern California by Sunday night, likely weakening to a tropical storm. But the National Hurricane Center still expects strong winds and heavy rains ahead of that.
SDG&E increased its field crews and staged equipment to respond to potential or prolonged power outages quickly, according to a news release.
Wagner added that if anyone spots a fallen power line, call 911 immediately. Do not touch it because it could still be energized and cause a harmful shock. If residents smell gas, they should leave the area immediately and call 911.