The Charles Krug Winery, Napa Valley’s oldest, has joined a growing number of California wineries turning to the sun for more than just growing grapes. The winery is becoming the latest to add photovoltaics to reduce its grid-supplied electric demand. It’s also taking advantage of the installation to reduce its energy use.

The Napa Valley winery in Saint Helena owned by the Peter Mondavi family, is installing a 1.2 megawatt photovoltaic system. When completed it will provide more than half of all the winery’s current energy needs, according to Christine Piccin, a spokesperson for the winery. She said the system will help cut the overall costs of electricity at the winery as well.

Since the array is being built as a canopy that will provide shade for the winery’s outdoor fermentation tanks it will provide passive cooling for them, reducing the amount of energy used to cool them. The system is being installed by Blue Sky Utility, which is working with Bright Power, Inc. to design and install the system. “The winery will own the system [when completed],” Piccin said. 

The winery chose to undertake the solar project and others aimed at reducing the winery’s energy use after undergoing a comprehensive energy efficiency review, according to the winery. As such, the project is part of a larger energy efficiency project at the winery that includes a system designed to draw cooler air into the winery’s buildings at night, further reducing inside temperatures and energy needs for cooling. “The night cooling system is a separate system which works with both high-efficiency electrical exhaust vents and gravity vents,” Piccin said. The entire system is scheduled to come online in December.


The winery also will complete a new lighting project in 2013. The lighting project will use motion sensors to turn lighting on and off as needed. And the winery is redesigning its refrigeration controls for its fermentation tanks and aging cellars. Once completed they will have on-demand control, with automatic shut down during peak hours.

Charles Krug joins a growing number of wineries that are using the sun for more than just growing their grapes. Among others, Treasury Wine Estates and Cade Winery are using solar to power their energy needs.