Shell Solar Industries will manufacture, assemble and work on site construction for a US $6 million, 1 MW single-axis tracking solar photovoltaics (PV) array for Semitropic. Half of the project is funded through federal and state grants to the district.

Semitropic is located in the San Joaquin Valley, and the utility stated that the array will be one of a number of energy sources feeding the facility's distribution system and water pumps.

The PV system is designed with an enhanced tracking system, said Gordon Handelsman, who is Shell's senior director of Sales and Marketing for the Americas. Designing a tracking system is challenging because the moving parts of the system need to stand up to the elements as long as the PV modules will.

"The difficult thing is getting something that does (the job) perfectly all the time," he said.

Improvements to Shell's tracking system are significant enough that the company has applied for a patent on the system.

Energy output for the array at Semitropic should reach 1.75 million kWh of electricity per year, and provide the district with a reduction in annual utility charges. Panels are assembled at the Shell facility in Camarillo, California, and the final array will have 1,920 panels of the 510 W Shell PowerMax Ultra modules. Panels will be attached to the tracking system at the factory and then shipped to the construction site as a complete unit to make system installation easier. Work on the array should be completed in early Spring of 2005.

Energy from the array could also be used to power an on-site hydrogen generator, because the utility has plans to convert a few of their trucks into fuel cell vehicles for the district. Trucks currently in the Semitropic fleet are run with propane, and auto manufacturers aren't producing propane-fueled trucks anymore, according to information on the utility's Web site. Reverting back to underground storage tanks for gasoline or diesel fuel isn't appealing, and fuel cell vehicles should be better for the environment and easier on the district's pocketbook.