MODESTO -- Two hours after sunrise Saturday, the big new solar plant on McHenry Avenue was impressing a group of visitors.
The plant, built for the Modesto Irrigation District, was one of the stops on a tour showcasing how sunlight can make electricity.
"We need to clean up the air," said Frieda Rector of Modesto, one of nearly 100 people who visited the plant. "This is a source we can use that won't pollute the air."
The tour was sponsored by solareverywhere.org, which promotes the technology, and the Civic Engagement Project at Modesto Junior College.
It also took in four residential systems; an array at Church of the Brethren, west of Modesto; and the MJC classroom where Adrian De Angelis teaches the technology.
The MID has relied mostly on wind turbines in the Pacific Northwest to get closer to a state mandate for at least 33 percent renewable power by 2020.
The McHenry plant, which started feeding the grid in July and is undergoing final testing this month, is expected to provide only 2 percent of the supply.
Officials said the project is worthwhile nonetheless because it will help meet peak demand on summer afternoons and evenings, when power on the wholesale market is pricey. The panels have small motors that allow them to turn as the sun crosses the sky each day.
Some customers have criticized the MID for paying 17 cents per kilowatt-hour for the solar power over 25 years, about double the current cost of conventional sources such as natural gas.
"What they like about this is once you build it, the fuel is free," said tour guide Paul McMillan, principal for the utility group at SunPower Corp. of San Jose, which built the plant.
The company has spent more than $150 million on the project, the largest solar installation in the Northern San Joaquin Valley by far. It covers 155 acres of open land at the northeast corner of McHenry Avenue and Patterson Road.
The panels are made up of photovoltaic cells, which when struck by sunlight release electrons that then create a current.
The visitors did not see the panels at their best. The glass surfaces were dusty because the ground beneath them had just been harrowed to remove weeds.
The panels will be washed as needed, said Sean Gallagher, managing director for government relations at K Road Power Holdings LLC.
This company, which has offices in San Francisco and New York City, bought the plant in May but kept SunPower on to manage it.
Bee staff writer John Holland can be reached at firstname.lastname@example.org or (209) 578-2385.
AT A GLANCE
The discussion of the sun's potential will continue Wednesday with a talk at Modesto Junior College. Randy Schack of Great Valley Energy Solutions will speak on the science and economics of rooftop solar electricity for Modesto. It will be from 4 to 5 p.m. in Science 208 on the east campus. The talk is part of the college's weekly Science Colloquium.
Utilities offer rebates and other incentives for solar electricity systems at homes, businesses and other sites. Customers can combine them with income tax credits for substantial savings.
Modesto Irrigation District: (209) 526-7455 or www.mid.org/rebates. The MID has about 10 megawatts of solar capacity from customer-owned systems and 25 from the new plant on McHenry Avenue. This is about 3 percent of total demand.
Turlock Irrigation District: (209) 883-8218 or www.tid.org. Customers have installed 6.75 megawatts of solar, a tiny part of total demand.
Pacific Gas & Electric Co.: (877) 743-4112 or www.pge.com. Solar provided 0.5 percent of the utility's power as of 2010.