Solar system saves school district $492K in first year

A year after finally getting its long-delayed solar power project complete and online, the Sonoma Valley Unified School District saved almost a half-million dollars in electricity costs from Oct. 1 of last year through Sept. 30 of this year.

At Tuesday night’s school board meeting, Steve Kwok, a principal in Quattrocchi Kwok Architects, QKA, the company that designed the system, told the district board that the savings since the system went on line in October of last year amounted to $492,000, and with $600,000 in PG&E rebates so far, it has pumped almost $1.1 million back into the district’s general fund.

The rebates are estimated to be around $720,000 a year for five years – or about $3.6 million. The system cost almost $10.4 million.

“This is money that can now be spent in the classrooms,” Kwok said.

Justin Frese, the district’s deputy superintendent, said the savings covered almost all of the district’s electricity bills. Frese said the district was required to build the solar system for each of its electric meters. “Some campuses have several (electric) meters, and there were certain ones that weren’t worth converting (to solar),” he said.

While the district isn’t generating any excess power, it shouldn’t be affected in the event it adds electric usage in the form of appliances or HVAC units in the future.

“We do intend to try and cover future additions with the solar we have,” Frese said. “Our intention is to try and continue to lower our electrical consumption through efficiencies, and then use this saved energy towards potential new uses.”

The solar system is delivering what the district expected it to, he said. “The electric bill is largely avoided, rebates are coming in and cuts were avoided.”

So far, with the exception of taking so long to get online, there haven’t been any glitches in the system.

The contract originally called for the project to be done over the summer of 2011, but instead of three months, the project took longer than 12 months to complete. “We have reached an agreement with Roebbelen (the contractor) which closes out the contract and has taken the extra time into consideration,” Frese said.

At Tuesday’s meeting, board President Dan Gustafson asked if there would be any maintenance costs associated with the system.

Kwok said everything is under warranty for the first 10 years, so there wouldn’t be any cost through 10 years.

“Around the 12-to-15-year mark, the inverters will have to be replaced,” he said. “But right now, I don’t have any idea on what they would cost.”

In his PowerPoint, Kwok pointed out that the system generated 2.3 million kWh (kilowatt hours), which is equal to the electricity to power 292 average homes.

“It offset 1.7 million pounds of CO2, which is equal to preserving 326 acres of rain forest,” he said. “Over 25 years, it will offset 40 million pounds of CO2, which is equal to 42,175 barrels of oil.”

Kwok also touted the educational benefits of the system, including live data on energy production available at each school and online.

The solar project got its start in the summer of 2010 when an energy master plan was completed. It was a part of Measure H, a $40 million school bond that the voters approved in November 2010. The district started accepting proposals in December 2010 and, in January 2011, selected Roebbelen as the general contractor.

Construction started in June 2011, but it wasn’t until June 2012 that the first two sites were interconnected and October 2012 that all sites were interconnected and generating power – and rebates.

Over the next 25 years, the district expects to save $26 million in electrical costs with the system.