The San Francisco Board of Supervisors unanimously passed legislation that obligates all new constructions shorter than 10 floors to install solar panels or solar water heaters on top of both new residential and commercial buildings.
“By increasing our use of solar power, San Francisco is once again leading the nation in the fight against climate change and the reduction of our reliance on fossil fuels,” said Supervisor Scott Wiener, who put forth the legislation, in a statement. “Activating underutilized roof space is a smart and efficient way to promote the use of solar energy and improve our environment.”

San Francisco is famous for its foggy days. As it’s surrounded by water on three sides, inland heat tends to draw cool ocean air across the city, shrouding it in fog. But contrary to popular belief, solar panels do work in the fog, because some of the light can reach the panels. There’s even a small advantage, as the fog keeps panels relatively cool, which improves their efficiency. Overall, SF compares well with other cities in the sunny state of California, and it’s definitely one of the cities where solar panels are worth installing.
Renewable energy has developed significantly in California, with the state being required to obtain at least 33% of electricity from renewable sources other than large hydro. In 2014, solar provided 4.2% of the state’s energy, while wind chipped in at 8.1% and geothermal came in with 6.1%, for a total that’s under 20%. But with measures like these, California’s green energy will certainly develop.
The new rules don’t go into effect until January 1, 2017. The legislators also introduced a backup possibility for people who don’t want solar panels on their buildings: installing a garden or green area on top of the building, instead of the solar array.