Water-pumping plant in Yolo County to be powered by the sun

Created 10/09/2009 01:00 pm

Sacramento Business Journal - by Melanie Turner Staff writer

Motivated to save rate payers money, a Yolo County reclamation district is set to begin harnessing the sun’s energy to power its largest recycled-water pumping plant. The plant accounts for as much as 15 percent of the district’s power consumption, said Lewis Bair, general manager of Reclamation District No. 108.

The 383-kilowatt solar system, constructed this summer, cost the district $3.7 million to build, Bair said. RD108 financed the project with a long-term municipal lease with GE Capital. "RD108 has always been progressive in many aspects of supplying water, and this is just one more thing we can add to that progressive thinking,” said Fritz Durst, president of the district's board of trustees. "Our ultimate goal here, unlike companies that need solar for image, is purely financial. We're doing this to save money for our ratepayers." But how much they will save is unclear.

The district approved the solar project earlier this summer. Bair said he expects the system, which sits on about 6 acres 15 miles north of Woodland in Yolo County, to be plugged into the Pacific Gas and Electric Co. grid in about two weeks. RD108 delivers water from the Sacramento River to almost 48,000 acres in northern Yolo and southern Colusa counties. The district's Sycamore Slough pumping plant, which will be powered mostly by the solar plant, redirects water that otherwise would flow off agricultural fields and back into the river. Recycling the water for irrigation saves on irrigation costs and helps prevent lower-quality water from getting into the river.

Originally built in the early 1980s, the recycling system collects water runoff from the entire district and delivers it back to about a third of the district's land, Bair said. RD108 recently signed a contract to expand the system and deliver recycled water to another 1,200 acres, or about 10 percent of its service area. "It's an investment that's ongoing," Bair said, adding that "the district already has invested in water efficiency and conservation, including $40 million for two fish streams. Because water runs from all fields into the district’s drainage system, sometimes there’s too much water for the recycled-water pumping plant to handle. In that case, a second plant pumps excess water back into the river."

The expansion “will allow us to capture more of it,” Bair said. “Before we captured 75 percent of drainage. This will get us up to about 95 percent. The recycling-system expansion is set to take place next summer. Meanwhile, RD108’s annual PG&E bill is about $1 million, including $150,000 for the recycling plant. The district hoped the solar project would reduce that bill so the district could pass savings along to ratepayers, who pay for flood protection, agricultural irrigation and drainage. "I work for the farmers. This was really a business decision for them,” Bair said. “We thought we were going to save 15 percent or so. It turns out, however, that it might be “more like a break-even type of investment,” he said. In trying to determine whether the system would save on electricity costs, Bair considered a hypothetical 2.5 percent annual PG&E rate increase. He said the rate would have to go up by more than 2.5 percent to result in a savings. But Durst said he believes the solar power plant eventually will save the district money. "The question," he said, "is how much. The numbers we used were very conservative numbers,” Durst said. “When the economy turns around here, I think energy will get expensive again and we’ll go back and make our model look much better."

PG&E’s agricultural rates went up by a net 6.4 percent in the past 12 months, the utility said. Next year, PG&E has proposed a one-time bill credit to agricultural customers based on usage. For each year that RD108’s solar project produces energy, the district also will receive renewable-energy credits. As California moves toward increasing its use of renewable energy, the credits may increase in value as districts that don’t provide their own solar power, for example, seek to buy credits. While speculators say such credits may someday be worth $30 each, the district estimated their value on what is now a voluntary market at closer to $5.

The primary contractor on the solar project was Ascent Builders Inc. of Sacramento. Subcontractors included Solar Development Inc. of Roseville and Meca Solar, whose parent company is Spain-based Otras Producciones de Energia Fotovoltaico. Meca Solar manufactures MECASolar tracker systems that can increase total energy production by 36 percent compared to conventional fixed arrays, according to the company.

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