Wednesday's warm and sunny weather was propitious for the new solar-powered traffic light at Woodbury-Glassboro Road in Mantua Township, at the entrances to a Target store and Timber Creek Shopping Center.

"We are always looking for ways to use green energy, so we're happy to be the first to be doing this," Gloucester County Freeholder Heather Simmons said of the four-way signal, which is topped with six solar panels.

It is the first of its kind in New Jersey, according to the state Department of Transportation.

More traffic lights in the county will go solar by the end of next year, said Simmons, who serves as liaison to the county Department of Public Works.

The conversions will be financed by a $298,000 U.S. Department of Energy grant. Locations will be chosen based on access to sunlight, rendering undesirable lights shaded by trees, buildings or even power lines, Simmons said.

Municipalities pay the energy costs for their traffic signals no matter whether they are on federal, state, county, or municipal roads, according to state regulations. Mantua expects to save from $450 to $550 a year for each traffic light it converts, Simmons said.

"But it is not only that: It is that state rules are making municipalities have more green energy," she said, noting that municipalities will be required to get 20 percent of their energy from renewable sources by 2013.

County Engineer Vincent Voltaggio said he believed the signal might be the first in the country to use solar panels.

"I found one in Nebraska that uses a wind generator, but maybe Gloucester County will be the hub of solar-powered traffic signals," Voltaggio said. "Whatever we can do to hold down carbon emissions and energy costs, we are all for it."