The wind reminded the third generation Mendota, Calif., farmer that cotton planting time was drawing near, but on this blustery afternoon the quiet Locke and his family were focusing on hosting a cotton trailer load of politicians, business entrepreneurs and bureaucrats as well as their farming neighbors at a dedication of what was billed as the largest solar powered farm irrigation pump ever installed.
"We didn’t expect all this attention when we signed up to take on this project," smiled Locke, admittedly more comfortable out of the glare of publicity than in it.
Nevertheless, Locke was thrust into the role of highly praised pioneer for his willingness to spend about $125,000 for half the cost of installing a 35-killowat, 50-horsepower solar-powered irrigation pump on his farm. Utility rebates and state grants paid the other half.
Locke said the idea of investigating solar energy for irrigation pumping power came from nephew Gary Martin, but it did not take much convincing to get Locke to look seriously at the new idea because of rising energy costs for pumping irrigation water.
"Solar energy is a proven resource that offers both economic and environmental benefits," said Martin, a fourth generation of the Locke family to farm. "Working with WorldWater Corp., we hope to demonstrate to others that solar energy is a viable alternative for farmers and one that makes sense."
Resembles pole barn
WorldWater is a New Jersey corporation with a division in California. It developed the AquaMax solar water pumping system. On the D.T. Locke Ranch it uses an elevated 108-long solar array that looks like a pole barn to capture the sun’s energy to power the 50-horsepower irrigation pump. Fifty-horsepower is on the lower end of the horsepower scale for most irrigation pumps on the West Side of the San Joaquin Valley.
The patented system converts and uses DC and AC current powering the pump from either the solar array or from the electrical grid.
Locke called it a "zero out" system. "When there is no solar energy to run the pump, electricity kicks in. When the pump is off, any electricity from the solar system goes back to PG&E," Locke said. "We do not get paid for any excess going back into the lines, but we are not charged for any electricity we use either." There is no battery storage.
The solar panels also are connected to the ranch’s shop and a home. Locke figures it will take about six and a half years to recoup his investment from not paying power bills.
Solar energy is nothing new. It has been around for at least three decades, but its use has been restricted mostly to residential use or small-scale commercial uses. California’s utilities have worked at developing it. Pacific Gas and Electric Co. operates a large solar energy plant in the desert near Barstow, Calif.
Quentin Kelly, chairman and CEP of WorldWater Corp., said solar energy for water pumping has had a five-horsepower technological ceiling until now. The AquaMax patented technology has broken through that ceiling.
In addition to the Locke irrigation pump, WorldWater is installing a 300-horsepower HydraCooler for food processing refrigeration at Lehr Brothers Inc. of Edison, Calif. WorldWater is also installing two 500-horsepower and two 300-horsepower well pumps for the Joshua Basin Water District in Southern California.