The second largest single solar installation operated by a South County government agency could start reducing wastewater treatment power costs for Manteca ratepayers by 2016.

The city is going out to bid within the next month or so for a one megawatt solar farm project on the north side of the treatment plant along Yosemite Avenue.

It will supply roughly a third of the electricity needed to run the plant.  The city’s current PG&E bill for the treatment plant is $1.2 million on an annual basis.

“The project has an eight year payback while the life expectancy is  25 years,” John Clymo, Manteca’s Deputy Director of Public Works/Utility Services, told the Manteca Rotarians meeting Thursday at Ernie’s.  “That means for 17 years the city will be getting free electricity.”

Electricity is the highest cost involved in running the wastewater treatment plant.

The largest single solar installation serving the South County is the 1.6-megawatt Robert Schulz Solar farm operated by the South San Joaquin Irrigation District to provide almost all the power needed for the surface water treatment plant that provides water to Manteca, Lathrop, and Tracy. It is helping to keep costs down for drinking water in the three cities.

The largest aggregate solar installation, though, are all the panels operated at various Manteca Unified School District sites.

The solar panels generated 27 percent of the district’s power needs in 2013-14 saving roughly $500,000.