Floating Solar Panels at Winery
Far Niente winery is one of Napa’s oldest winemakers. Operations began there in 1885. Now it holds another distinction, as one of the few wineries running almost entirely on solar power. Their unique installation of floating solar panels was implemented to conserve precious land for growing grapes. What follows is an interview with Greg Allen, who is their Dolce winemaker.
How many solar panels are you currently using, and will you add more?
There are 994 panels floating on the pond in our Martin Stelling Vineyard, with an additional 1302 land-mounted panels adjacent to the pond. There is no more room for additional panels, but there’s no need, either, as our Floatovoltaic installation currently satisfies our goal of offsetting all of our electrical energy costs.
What advantages were gained by making the solar panels float?
The biggest advantage was that we were able to use far less vineyard acreage for solar panels. By going over the water and not having to rip out nearly an acre of Cabernet Sauvignon vines, we spared the loss of approximately $150,000 of annual revenue from the wine we make from those vines. The area of land where we did pull out vines was a vineyard block that was not making the blend consistently, so it wasn’t a hard decision to lose those vines.
Over the three years we’ve been live with our Floatovoltaic system, we’ve found that under certain conditions the panels mounted on water stay cooler. Since temperature impacts panel performance (generation), we expect these cooler, floating, panels to be more productive than the land-mounted panels on particularly hot, windless days. We also suspect we’re experiencing less evaporation of the pond water, although we haven’t been able to measure it. This is important because the pond collects grey water from the winery, which we use for irrigation and frost protection in the vineyard.
What is the power generated by the panels used for?
The entire Far Niente winery estate is powered by the panels, including our winemaking operation, lights, computers, etc.
How much of your facility’s energy is generated by solar power?
This is difficult to generalize because our energy requirements are dependent on the size of our harvest and yields can vary wildly from year to year: in short, more grapes requires more energy! Instead of paying the normal monthly bill, every 12 months we balance the books with PG&E, measuring how much energy we produced and put on the grid, versus how much we pulled off of the grid. The last three years have shown that we’ve produced over 95% of our energy needs and offset 100% of our energy costs – a substantial and remarkable accomplishment.
Are visitors allowed to view them?
The installation is not included in a winery tour, but we do have images and information on our website.
What is used to store the power generated by the panels?
In the State of California’s rebate incentive programs, businesses are not allowed to store excess self-generated power. Ours is a net-metered, grid-connected system, so anything we don’t use goes back onto the grid and PG&E uses that power elsewhere.
Were any tax breaks credited to the facility for using solar?
No. We participated in California’s Self Generation Incentive Program (SGIP, since replaced with the slightly different California Solar Initiative incentive, CSI, program) which afforded both a cash rebate and non-cash incentives including a federal tax credit and accelerated depreciation. We negotiated a novel leasing program with Bank of America Leasing and Capital where we exchanged the non-cash incentives for a favorable lease rate and buyout option (coming soon) – they took the tax credit and passed the savings to us in the form of the lease rate.
Image Credits: Far Niente Winery