San Diego is on a list of the top 25 U.S. metro areas with the largest number of energy efficient buildings. The ranking is from the federal Environmental Protection Agency.
The cities are ranked based on the number and performance of Energy Star labeled buildings in 2009.
San Diego ranked 17 on the list. Los Angeles was number one, San Francisco ranked third and Sacramento was ranked 16.
Buildings receive the EPA's Energy Star designation by meeting strict energy performance standards.
San Diego had 58 such buildings last year. The EPA said those buildings prevented emissions equal to the electricity use of 4,300 homes.
Andrew McAllister with the California Center for Sustainable Energy said many building owners find the Energy Star label is good business.
"It's both good economics and good business right, so you have that star so it attracts good tenants and demonstrates quality and it also saves you money on the bottom line," said McAllister.
He said a building operated by the city of San Diego received the first Energy Star designation when the program started in 1999.
The EPA said energy use in commercial and industrial buildings accounts for nearly half of the yearly energy consumption in the U.S.
"These cities see the importance of taking action on climate change," said Gina McCarthy of the EPA. "Communities from Los Angeles to Louisville are reducing greenhouse gases and cutting energy bills with buildings that have earned EPA's Energy Star."
The EPA said energy use in commercial buildings accounts for 17 percent of U.S. greenhouse gas emissions at a cost of more than $100 billion per year.
The EPA first issued its ranking of regions with the most Energy Star labeled buildings last year.
