舊金山通過在 2017 年之後的建築物必須有 15% 的屋頂面積必須是太陽能相關的設備：「San Francisco Is Requiring Solar Panels on All New Buildings」：
The ordinance, passed unanimously by the city’s Board of Supervisors, extends an existing California law which requires 15 percent of roof space on new buildings to be “solar ready” — available and unshaded. That ordinance applies to residential or commercial buildings 10 stories or shorter.
也就是說，可以是太陽能的發電，也可以是太陽能集熱的設備：
Under the new ordinance, which will go into effect in 2017, new buildings need to have solar energy of some kind installed, either electricity-generating panels or solar heating units.
希望在 2020 年達到 100% 再生能源的目標：
San Francisco took a major step toward its own goal of meeting the city’s electricity demands with 100 percent renewable energy by 2020.
這成為美國第一個主要城市通過這樣的規範：
This week, San Francisco became the first major U.S. city to require all new buildings to have solar panels on their roofs, according to Scott Wiener, the city supervisor who introduced the bill.