Sun rising on California's power horizon

(11-24) 17:27 PST -- Solar power accounts for less than 1 percent of California's energy resources, but Bay Area residents are buying systems in increasing numbers, which is good news for the environment and the solar industry, advocates say.

Californians have more than 60 percent of the nation's solar installations, and more than 66 percent of the state's solar applications are in Northern California, according to a report released Monday by the Northern California Solar Energy Association, a nonprofit advocacy group.

For 2007, statewide there were 50,466 photovoltaic installations, yielding 244 megawatts of electricity, according to the report.

The report also tracks energy installations for 165 cities in the nine Bay Area counties plus Santa Cruz County.

It finds that the installations statewide, for homes and commercial facilities, generate nearly 400 megawatts of power (one megawatt serves 750 homes), and the number is growing. Over the past several years, Californians have installed from 30 to 40 percent more systems than the year before, and 2008 is expected to show an even greater increase.

Among other findings:

-- Santa Clara County has the most solar installations among the region's counties, with 2,462. That's far more than second-place Alameda's 1,699.

-- Napa County is first among counties in watts per capita, with 51.3.

-- Santa Rosa is first among large cities in watts per capita installed, with 29.9.

-- Berkeley has the highest number of solar systems per 1,000 citizens, with 4.17.

-- In the Bay Area and Santa Cruz County, there are 11,563 solar projects, built at a cost of $746 million, producing more than 84 megawatts of electricity, according to the report. The report includes installations as of Dec. 31.

Gary Gerber, president of Sun Light and Power in Berkeley and a sponsor of the report, said, "The information provided by this report is absolutely critical to understanding this industry, and the growth that this report demonstrated in the popularity of solar energy is truly impressive."

The California Energy Commission and the California Public Utilities Commission track solar usage as well. The energy commission found that in the past two years, since a state program promoting solar energy was launched, there have been 17,000 solar energy installations placed on homes and businesses, said spokeswoman Amy Morgan.

Solar power is increasingly popular because it's clean. It causes no emissions and does not contribute to global warming. Fossil fuels, such as coal and natural gas, release carbon dioxide into the atmosphere that traps heat like a greenhouse and raises temperatures.

In 2005, Gov. Arnold Schwarzenegger launched an effort called the Million Solar Roofs plan, to encourage property owners to install a million solar roofs in California by 2018.

In August, he signed legislation that continues a property tax exclusion for projects that utilize solar panel energy and expands the exclusion to builder-installed solar energy systems in new homes. The original property tax exclusion was passed by voters in 1980.

On Nov. 17, Schwarzenegger signed an executive order that aims to streamline the state's renewable energy project approval process and seeks to increase renewable energy usage to 33 percent of the total by 2020.

Currently, renewables represent only 11.8 percent of the total system power in the state for major installations.

E-mail George Raine at graine@sfchronicle.com.