Did you know that San Francisco is the nation's first city to require solar panels be installed on all new buildings that are 10 stories high or less? This new requirement was passed with a unanimous vote by the San Francisco Board of Supervisors in recent weeks.

“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,” Supervisor Scott Wiener, who is sponsoring the legislation, said in a statement. “Activating underutilized roof space is a smart and efficient way to promote the use of solar energy and improve our environment."

The law makes it mandatory for all new construction to have a minimum of 15% of rooftops 'solar-ready', which means they aren't shaded and as such can capitalize on the maximum effects of solar panels. Thought the rule doesn't go into effect until January 1, 2017, but buildings still under construction will have to add panels retroactively if their aren't already installed or in the plans.

Smaller California towns like Sabastopol and municipalities in the Central Valley have already enacted solar panel requirements in keeping with the green movement toward achieving zero-energy buildings.