In the widening embrace 
of renewable energy, cities have become a catalyst. For example, San Francisco recently approved an ordinance requiring solar panels on all new residential and commercial buildings constructed in the city beginning in January 2017.


The ordinance, authored by Supervisor Scott Wiener, applies to any building with 10 floors or less and more than 2,000 square feet of gross floor area. The technology may be either solar photovoltaic or solar water panels.


Wiener was ebullient after his colleagues unanimously approved the measure in April.


“San Francisco is once again leading the nation in the fight against climate change,” he said, noting that the measure will help move the progressive city closer to its goal of becoming 100 percent powered by renewable energy. “Activating underutilized roof space is a smart and efficient way to promote the use of solar energy.”


In one respect, the new law is not such a leap. Updated in 2013, California’s Title 24 Energy Standards require 15 percent of roof area on new small and mid-sized buildings to be “solar ready.” Shading must be avoided, and the appropriate roof spacing and electrical infrastructure must be included in initial construction to make it ready for the potential future installation of solar technology. 


The San Francisco ordinance builds on that readiness by adding the requirement that the technology actually must be installed.