San Francisco to become first city to require solar panels on new buildings

Beginning January 1, 2017, San Francisco will require rooftop solar systems on all new buildings under 10 stories – the first mandate of its kind in the United States.

The city's Board of Supervisors unanimously approved legislation Tuesday that will require all future commercial or residential buildings under 10 stories in height to install solar systems for heat, electricity, or a combination of the two. The California cities of Lancaster and Sebastopol, which have populations of about 160,000 and 7,600, respectively, have already enacted similar mandates, but San Francisco is the first city of considerable size to require solar roofs.

"This legislation will activate our roofs, which are an under-utilized urban resource, to make our City more sustainable and our air cleaner," Supervisor Scott Wiener, who introduced the legislation in February, wrote in a press release. "In a dense, urban environment, we need to be smart and efficient about how we maximize the use of our space to achieve goals like promoting renewable energy and improving our environment."

Under California's Title 24 Energy Standards, state law requires all commercial and residential buildings under 10 stories to designate 15 percent of rooftops as "solar ready," free of shading or obtrusions. San Francisco's ordinance is taking this existing state law one step further by mandating that these "solar ready" areas are actually utilized in future construction, with the installation of either solar photovoltaic panels or solar water heaters.

Some critics consider the ordinance "political grandstanding" with limited applicability, given the 10-floor restriction.  

But unlike other large US cities, the ordinance's 10-floor restriction doesn't render the concept ineffective. San Francisco is famous for its low skyline, with numerous zoning laws in place to preserve the city’s historic buildings, residential neighborhoods, and even its sunset views. 

"This ordinance represents one more straightforward and pragmatic step toward that goal," Barry Hooper, the Department of Environment green building coordinator, told The San Francisco Examiner last week. "It's been demonstrated as being highly cost effective."

Costs will vary depending on the solar system's size, but the typical price tag is $20,000 for a residential solar installation, with the price decreasing for larger, more industrial installations. The ordinance could have a real environmental impact, however, as The Examiner reports. Increasing the city’s solar system by 7.4 megawatts would power about 2,500 homes in San Francisco, while eliminating 26,000 metric tons of carbon dioxide from the atmosphere with every 200 installations. 

San Francisco is often an environmental leader in California, a state typically named as an environmental leader in its own right. For example, the state will require 50 percent of electricity to be fueled by clean energy by 2030 – the strongest mandate of any state. But true to form, the city of San Francisco has its own, bolder version of the state's goal: 100 percent of electricity needs to be fueled by clean energy by 2025. 

Similarly, in 2007, San Francisco became the first city in the United States to ban plastic shopping bags, a measure many communities across the country have since adopted. In November 2016, California voters will decide on the California Plastic Bag Ban Referendum, potentially bringing San Francisco's plastic bag legislation to all of California.