Soon, there will be a little bit of sun in your can of Creamy Tomato Soup (enjoyed with a grilled cheese, of course), thanks to a Campbell’s Soup Co. (NYSE:CPB) decision to put a 9.8-megawatt photovoltaic array at its largest plant in Napoleon, Ohio. The array, which is being installed under a 20 year power-power purchase agreement with BNB Napoleon Solar LLC, will allow the soup-maker to shave roughly $4 million off its electric bill over the contract period.

BNB, a subsidiary of BNB Renewable Energy Holdings, will lease 60 acres of the 900-acre Napoleon campus, said Robert Shober Campbell’s vice president of infrastructure engineering and environmental programs.

“Hopefully, everything will go right,” he said. “We’ll have the construction start in June and have it completed by the end of December.”

It’s the first time Campbell’s has really gone solar.

There’s a small array, about 100 kilowatts, in at its Toronto, Canada facility.

“We’ve thought a lot of different ways about how to go about it,” he said. “About eight months or a year ago, we decided to go with the power-purchase agreement.”

The 9.8-megawatt array will cover just a portion of Campbell’s energy needs at the facility. Shober explained that it will produce about 15 percent of the campus’ energy needs.

“What’s interesting about the Ohio plant is it’s our largest facility. It’s just under 3 million square feet,” he said. The company makes a lot of its soup products, as well as its juice and sauce products at the facility.

Making the soups and other products at the plant is a resource-intensive process that requires a lot of energy as well as water, according to Shober. For instance, the soups are actually cooked in their cans in boiling water and then rapidly cooled back down, using a lot of gas heat, and electricity.

The company’s been doing a lot to reduce its energy and water consumption, Shober said.

It joined the Environmental Protection Agency’s Climate Leaders program, promising to reduce its greenhouse gas emissions by 12 percent between 2005 and 2010. And just yesterday the company filed its results with the agency.

“We just sent them all our calculations, and we made that goal,” Shober said.

To reach the goal, the company took a lot of actions, from upgrading to energy efficient-lighting, to reusing water used in the cooking and cooling processes, to recovering heat from the cooking process.

“For years, that water was used once, and we discarded it,” he said. “Now we use heat exchangers, pumps and cooling towers to recover that heat and preheat water going into our boilers and then cool it back down to recycle it. It reduced the use of steam by 15 precent, reduced water use by 1 billion gallons.”

Pictured: Our tribute to the man who made Campbell’s image iconic: Andy Warhol.