Rooftop Solar Connected to Home Batteries

Canary Media: “Chart: More and more rooftop solar buyers are adding home batteries.” The proportion of people who install a backup battery in conjunction with rooftop solar is ramping up impressively in the U.S., according to a new report from Lawrence Berkeley National Laboratory or LBNL  The so-called ‘residential attachment rate’ was less than 10% in 2022, then 12.3% last yr, but projected to reach 25% this yr.  Unexpectedly, the country’s rooftop solar market was impacted—mainly by policy changes in California—as “the Golden State’s net-metering program took effect, slashing the rate at which rooftop solar owners could sell surplus power to the grid but boosting the value of batteries, which enable homeowners to save their solar power for the times when it’s most valuable.” Thus solar installations are projected to fall 19% this yr while the attachment rate in California rose to 14% last yr. But policy is not the only driver. “Extreme weather events, made more frequent by climate change, are increasingly threatening grid reliability.” Furthermore, batteries continue to become more affordable. “And rising utility rates are making the economics of solar-plus-storage more attractive to homeowners.” Cost of electricity is especially a factor in Hawaii, which had the country’s highest charges last yr, but also the highest residental battery installation rate, at 95%. “Big, utility-scale battery projects are being built across the nation at a rate that would have been hard to fathom just a few years ago.” But these new data from the LBNL show a similar upward progression for home battery systems, too. We built a new home in 2019 with solar + batteries, which allowed us to weather 6 brief grid outages this yr already.  Resilience should be the organizing principle, at both local + grid level.