Rombauer Vineyards


St. Helena and Napa, CA


Stellar Energy installed a roof-mounted solar photovoltaic (PV) power system at the winery in St. Helena, CA and a second solar array at their temperature controlled warehouse in Napa, CA. The solar energy system is composed of two separate roof-mounted solar electric arrays. It produces a total of 671 Kilowatts and consists of 2,856 solar modules, 3 Satcon Inverters, and internet-based monitoring to measure and display performance.


The winery's elegant tasting room and active production facility had limited space to accommodate a solar installation. To maintain the winery's attractive appearance, electrical sub panels and inverters needed to be installed out of plain sight. The solar modules were to be safely installed on a steep metal roof during the hot summer months.


Stellar Energy's experienced project managers knew how to handle the construction process in a manner that did not interfere with the busy tasting room or the wine making business. Constructing special inverter pads on the side of a steep mountain allowed the winery to maintain their ascetics. To accommodate for extreme summer heat (reaching up to 134 degrees F) on the metal roof, the installation crews started their work day before sunrise.


Stellar Energy's engineers designed the smartest way to approach the project, which included moving to a more advantageous utility rate plan and relocating the electrical meters to a location to better serve the winery's future needs. The project ran smoothly from start to finish and Stellar Energy worked to complete the project ahead of the grape harvest, known as 'the crush'.

The most tangible benefits of this solar installation were financial, allowing the winery to save over $185,900 in annual utility bills, while still meeting 74.8% of their electrical needs. The environmental benefits produced by the system include offsetting over 650 metric tons of carbon dioxide, which is the equivalent to the annual greenhouse gas emissions from 116 passenger vehicles.


  • Energy Capacity: 671 kW DC total (2 sites)
  • # of Modules: 2,856
  • Type of Mount: Non-penetrating roof mount
  • Type of Inverter: 3 Satcon Inverters
  • Monitoring System: Solar Magic Internet-based monitoring

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