San Rafael, Calif.-based SPG Solar has commissioned Phase II of the 170 kilowatt commercial photovoltaic (PV) system for the Grgich Hills winery in Napa Valley, Calif.
Together with Phase I, completed in 2005, this second phase of the Grgich Hills PV installation will produce 170.08 kilowatts DC of electricity during peak production hours. Upon completion, the PV system is expected to meet 100% of the winery's actual energy needs, according to SPG Solar, adding that the system will pay for itself within five years.
‘It was an economic and philosophical decision to install a solar energy system at Grgich Hills. In creating a 100 percent self-sustaining winery, we wanted renewable energy to complete the cycle, and that's what solar provides for us,’ says assistant winemaker Kevin Vecchiarelli. ‘Grgich Hills owns the largest biodynamic vineyards in the United States, with all 366 acres in Napa biodynamically farmed and certified organic.’
SPG Solar president Dan Thompson notes that Grgich Hills' Phase I construction consisted of 192 Kyocera KC 190GT panels mounted on the corrugated steel roof of the wine storage area, feeding DC power into a Xantrex 45 kW inverter. Phase II is constructed of 668 Kyocera KC 200GT panels mounted on the red roof tiles of the winery and tasting room, feeding into a Satcon 100 kW inverter.
Thompson estimates that ‘over 25 years, this high performance solar system will have reduced over 1,091,000 pounds of carbon dioxide emissions, equal to saving 425 acres of rainforest or powering 1,150 homes for that same duration.’
The PV system produces excess energy in the winter, when the vines are dormant and the winery's energy use is lowest. The excess flows back to the power grid of the local utility for credit through the net metering process. The winery electric meter runs backwards on highly productive sunny winter days. Grgich taps into this utility credit during the summer grape-crush months when winery energy use is at its peak.
