Pacific Gas & Electric Co. and the San Francisco Giants said Wednesday that they would team up to place the first solar energy system at a major league ballpark.

But storm clouds are gathering over the plan to install nearly 600 solar panels at AT&T Park, the Giants' home field. Consumer advocates contend the project is little more than a publicity stunt and that shareholders, not ratepayers, should be footing the bill.

The panels will generate about 120 kilowatts of energy, enough to power more than 20 homes, utility spokesman Keely Wachs said.

Power from the 590 panels would be transmitted to the general power grid for PG&E to sell to customers around Northern California. The company plans to ask the California Public Utilities Commission for permission to bill those same customers for the purchase, installation and maintenance of the panels.

PG&E, a subsidiary of San Francisco-based PG&E Corp., and the Giants trumpeted the proposal in a news release complete with laudatory comments from executives and San Francisco Mayor Gavin Newsom.

"PG&E is committed to helping the Giants, the city and county of San Francisco, and all of the communities we serve to increase power generated from solar energy," said Tom King, chief executive of Pacific Gas & Electric.

The Giants noted that energy conservation had been a priority in AT&T Park's design and daily operations, including installation of a new Diamond Vision scoreboard that uses 78% less energy than the ballpark's original scoreboard.

But Jamie Court, president of the Santa Monica-based Foundation for Taxpayer and Consumer Rights, objected to the planned use of ratepayer funds for the solar project.

"This was an attempt to get a nice PR ploy, and if that's the case, then PG&E shareholders should pick up the tab," Court said.

Although PG&E has helped 15,000 customers connect their solar panels to the grid, representing 110 megawatts, the company currently doesn't own any solar panels.

PG&E has committed to spending more than $7.5 million on solar installations and has been attempting to burnish its image in San Francisco by sponsoring websites and advertisements promoting environmentally friendly energy.

One site, http://www.LetsGreenThisCity.com , lists classes that customers can take to learn about installing solar panels and incentives. Renewable energy accounts for 12% of the power that PG&E provides to its customers.