San Diego Gas & Electric plans to spend up to $250 million to install solar panels across the county over the next five years, the utility said Friday.

If all installation requests are approved by the California Public Utilities Commission, the program's first phase would generate 70 megawatts to 80 megawatts, enough to power about 5,000 homes, said Debra L. Reed, the utility's president.

More sites will be added in later phases, said Reed, who noted the project would be the largest solar power project in the county.

Reed outlined the program at Westfield Shoppingtown's University Towne Centre mall in La Jolla, one of the locations getting the solar panels. Rising as high as 12 feet, the "solar trees" will not only produce electricity from sunlight, the panels also will provide shade for vehicles. Moreover, these panels will move to track the sun's path, providing 40 percent more energy than conventional fixed panels.

Westfield said it is considering installing the panels at its other locations in San Diego County, including Westfield North County in Escondido and Westfield Plaza Camino Real in Carlsbad.

In addition, SDG&E is negotiating with Carlsbad, Chula Vista, San Diego and Santee to place solar plants in those cities. Each installation project will be presented separately to the state utilities commission for approval.

The initiative is one of several SDG&E programs to meet a state mandate to supply more electricity from renewable resources, such as solar, wind and geothermal power. Each program supplies a small part of the utility's peak power demand of 5,000 megawatts, but together with traditional fossil fuels will allow the utility to meet the county's energy needs, the utility said.

What's different about this program is that the electricity will be generated where it is used, SDG&E said. That means no new transmission lines, a controversial part of other programs. The utility's proposed Sunrise Powerlink, which would bring in solar, wind and geothermal energy from Imperial County, is opposed by some environmentalists and consumer rights activists as unnecessary and too expensive.

If all solar panel installation sites are approved, SDG&E said the average utility bill would increase by 28 cents a month.

Commission president Michael Peevey praised the utility for creative thinking. Not only does the on-site location avoid the need for new power lines, Peevey said, the solar panels will add more electricity when it is most needed, during the hottest hours of the day.

"What we have here today is an example of some real innovation by SDG&E," Peevey said. "It's an example of proactively embracing a new technology, not doing it just because you have to, but because you should."

Contact staff writer Bradley J. Fikes at (760) 739-6641 or bfikes@nctimes.com.