SAN FRANCISCO, April 22 (Xinhua) -- San Francisco Mayor London Breed announced a plan on Monday to make the city the first one in the United States to mandate 100 percent renewable power for commercial buildings the size of 50,000 square feet (about 4,645 square meters) or larger.
The plan, which was unveiled to celebrate Earth Day that falls on Monday, requires the city's largest commercial buildings to procure 100 percent renewable electricity from any of the city's electricity providers by 2022.
The city government is currently introducing a phased-in program to transition commercial buildings in the city that are 500,000 square feet or larger in size to 100 percent renewable electricity by 2022.
Commercial buildings that are between 250,000 and 499,000 square feet will have to switch to the scheme by 2024, while buildings over 50,000 square feet or larger will be required to adopt pure green electricity by 2030.
This initiative is set to help achieve Breed's goal of turning San Francisco into a carbon-neutral city by 2050.
"Transitioning our large buildings to 100 percent renewable energy is an important step to continuing the progress we have made with CleanPowerSF towards making San Francisco an even more sustainable city," Breed said.
Almost half of San Francisco's citywide emissions come from buildings, and half of them are from the commercial sector, according to the mayor's office.
San Francisco has already cut its greenhouse gas emissions by 36 percent below 1990 levels, information on the website of city and county of San Francisco showed.