San Diego has 4,507 rooftop systems that have been installed, compared to a little over 4,000 in runner-up Los Angeles, a city with a much larger population, according to the report by Environment California.San Jose, San Francisco and Fresno rounded-out the top five.Within San Diego County, Escondido ranked 17th with 709 systems, Poway was 26th with 544 and El Cajon was 28th with 533.In generating capacity, San Diego was tops with 36,775 kilowatts that are tied to the electrical grid, just ahead of Los Angeles. Poway ranked 41st, Escondido was 48th and Chula Vista 50th."San Diego didn't become the state's Number One solar city by happenstance -- it was the result of local policies and programs that encourage investment in solar power," Mayor Jerry Sanders said. "It's good for our environment, it's good for our reputation as a city that embraces innovation, and it's been great for our economy."According to the report, San Diego would rank among the top 25 countries in the world in solar generation capacity.Environment California noted that the city had the only solar rebate program for the general market, sponsored by the California Center for Sustainable Energy and San Diego Gas & Electric."The program has been particularly effective in driving solar power into the residential market," the report stated.Neither San Diego nor any other major city appeared in another ranking in the report -- the number of solar installations per resident.The leader in the per-capita ranking was Santa Cruz, with 1.44 systems per resident. San Diego area cities were Encinitas, 23rd; El Cajon, 24th; Escondido, 28th; San Marcos, 29th and La Mesa, 30th.You can read the study by clicking here.