Fruit grows on trees from the power of the sun. In California, fruit processing will now also be powered by the sun.
The Stapleton-Spence Packing Company built the state’s largest solar water heating system—20,000 square feet of panels—on the roof of its fruit processing plant in the Sacramento Valley town of Gridley, saving $20,000 annually, the company said. The company uses approximately 30 million gallons of hot water annually for operations and heating.
The solar water heating system was installed by FAFCO and BCM Construction. Although the Stapleton-Spence announcement said the solar panels “preheat well water that flows through the tubes of each panel,” the systems described by FAFCO on its website use what is known as indirect circulation technology. Instead of the water itself circulating through the panels, a heat transfer liquid runs through them. That heated liquid then moves on to a heat exchanger, where the water to be used is heated.
The system at the fruit processing plant preheats water to about 30 degrees Farenheit warmer than its standing temperature. From there it is sent to a boiler to create the steam the plant uses. Preheating the water reduces the use of natural gas by 37,584 therms, the company said. The plant uses a total of about 650,000 therms of natural gas annually, mostly to rehydrate dried fruit and to sterilize purees and juices before packing and shipping.
Like many renewable energy installations, the massive solar rooftop system will pay back the cost of installation in fairly short order—just three and a half years, the company said. A major factor in making that possible: the $476,000 in rebates the company will receive from the California Solar Initiative (CSI).