Last year 35 percent of all the electricity provided by San Diego Gas & Electric came from renewable sources — solar and wind — a record for the company and for any investor-owned utility in California.
That 35 percent puts the company well ahead of schedule for California climate change requirements of 33 percent by 2020.
SDG&E had four straight years of double-digit increases in the share of its power that is renewable, and then a 9 percent increase last year.
How electricity is generated is crucial because more carbon dioxide is put into the air from making electricity than from any other source in the U.S.
The bulk of the region’s power, however — 54 percent — came from burning natural gas. The gas is pumped from underground in Texas and New Mexico and travels to Southern California through interstate gas pipelines entering the state near Blythe. San Diego’s electric utility is also a gas company, so generating electricity by burning gas adds to profit.
Solar’s rise has been the fastest. SDG&E provided no electricity from the sun before 2011. But last year the sun created 18 percent of the utility’s power. An additional 615 megawatts of solar electricity is being manufactured on people’s rooftops, said Martin Learn, founder and president of Home Energy Systems, a solar system designer and installer. That means residents, schools and businesses are now making as much solar energy as a large gas-fired power plant.
Wind power from SDG&E inched up over the past decade, reaching 16 percent in 2014 and 15 percent last year.
About 11 percent of electricity came from unspecified sources, bought on the spot market.
Other, non-investor owned utilities in California provide even cleaner energy mixes. Among the greenest electricity providers, according to state documents, are Marin Clean Energy, Truckee Donner Utility District and the city of Ukiah with 57 percent, 50 percent and 49 percent renewable, respectively.
Marin Clean Energy is a nonprofit alliance of Marin and Napa counties plus several small cities that select clean electricity, then distribute it over utility company wires. The arrangement is known as a community choice aggregator.
Truckee and Ukiah are both city-owned utilities.
One boutique firm with a presence in San Diego says it provided 82 percent clean energy overall in 2015. The privately held 3 Phases Renewables in El Segundo was born during California deregulation and now offers businesses a custom mix of electricity.
SDG&E is one of three publicly traded utilities in California that together provide about three-quarters of all electricity delivered in the state. The other two are Southern California Edison and Pacific Gas and Electric.
