Wineries dot the gently sloping landscape of California's Sonoma Valley. At the base of a mountain, a hacienda-style winery with a red-tiled roof specializes in the production of red wines. Each summer, when electricity costs skyrocket in the Golden State, wineries draw electricity from the grid during times of peak demand to power their operations. To offset the high energy costs, the St. Francis Winery commissioned the installation of a 457kW photovoltaic system, which will provide green electricity year-round.

“A winery's business is tied to protecting the land and minimizing the impact of fossil fuels,” says Marco Miller, project manager for PowerLight, a Berkeley, Calif.-based firm that installs and maintains photovoltaic systems. “St. Francis Winery will be generating clean, quiet, efficient power from the sun. They hope that other businesses will follow their lead and be inspired to preserve the environmental quality in Sonoma Valley.”

To help St. Francis minimize energy costs, PowerLight will install a photovoltaic system on the rooftop of two of the winery's buildings — the wine-making facility and barrel storage building. A team of installers will use a custom-designed clamp to attach the photovoltaic system to the standing seam metal roof. Before installing the system, the team of engineers must make sure that the system is able to withstand the wind uplift pressures, calculate the roof load, measure the available roof area, and perform an electrical audit of the building.

Miller estimates that the project will take about three weeks from start to finish. The team will spend one or two days lifting the materials to the roof and spend the rest of the time working on the rooftop or inside the building.

“Our challenge is to not interfere with the operations of the winery,” Miller says. “They are going to start bottling their wine very soon, so we'll minimize any interruptions by working earlier or later in the day.”

The construction team will consist of about 10 to 15 workers, including four electricians. PowerLight works with certain electrical contractors on its commercial photovoltaic installations, and Miller says he plans to select an electrical firm as soon as he receives biddable drawings. The electricians will handle all the inside wiring, the conduit runs, the tie-in panel, the inverters, and the transformers.

“I like to bring electricians in at the beginning so we can start to plan out the conduit runs and the location of the equipment and the tie-in gear that they'll need prior to construction,” he says.

Rick Whisman, major accounts manager for PowerLight, says in addition to the photovoltaic installation, the team is also upgrading the winery's lighting system. The installers will convert high-bay lighting to T-8 or T-5 compact fluorescents. The lighting upgrade will significantly lower the winery's electrical load and improve the lighting of the areas that are most critical for its operations. PowerLight is also working with three other Sonoma Valley wineries to reduce their energy consumption and help preserve the environment.

“We want every winery to think of photovoltaics as a standard piece of equipment that they should consider for their facilities,” Whisman says. “It really makes good sense to hedge a certain amount of your electricity costs with your own on-site generation.”

Sidebar: Fast Facts About the St. Francis Winery

The St. Francis Winery and Vineyards was established in 1979. After adding more than 400 acres of land and expanding production over the years, the winery broke ground on a new facility that was located one mile from the original winery. The new facility, which was completed in 1999, features a Visitor's Center with two wine tasting rooms, a climate-controlled barrel storage building, and larger winemaking facilities. The winery is referred to as the “House of Big Reds” due to its specialization in red wines.