January 2015 Issue of Wines & Vines

Winery Solar Savings Threatened

Politics could end incentives and slow installations after 2016

by Paul Franson
Winery with solar
Chimney Rock winery is completely powered by a roof-mounted PV system.

With more than 100 California wine producers identified in public records as having installed solar arrays, wineries have been some of the most enthusiastic adopters of photovoltaic energy.

They’ve been doing it for a long time. Fetzer Vineyards in Mendocino County, Calif., has been operating on 100% renewable energy since 1999. This is through a 911 kilowatt (kW) photovoltaic system and another 40 kW photovoltaic system, with the remaining energy purchased from a direct-access provider that supplies energy from wind turbines. It also has upgraded equipment and processes to improve energy efficiency.

Shafer Vineyards in Napa Valley, Calif., says that in 2004 it was the first winery in the United States to use 100% solar power.

Future solar installations are threatened, however, by two political developments that could slow or end their installation, put an end to incentives and change aggregation costs to reduce benefits.

An end to incentives
The 30% federal tax credit for solar energy will expire at the end of 2016 unless it is extended.


  • Wineries have been leaders among businesses adopting solar power.
  • Installations are threatened by developments among public utility companies.
  • Wineries also are testing on-site storage to level energy demand and costs.

“We expect a backlog from wineries and other business that have been sitting on the sidelines for some time,” said Rob Erlichman, founder and CEO of Sunlight Electric. “With an expected surge in demand, we’re telling prospective customers that if they call us in Q3—maybe even Q2—we and just about every other competent solar integrator will be booked solid, and prices of panels might go up as they did in 2008. In other words, if a business is seriously considering solar, pulling the trigger in Q1 at least is the best way to ensure we can get the project done in time.”

This includes lead times for the electric utility company to do its final inspections, which are often delayed at the end of the year.

Nate Gulbransen, president of Westcoast Solar Energy in Rohnert Park, Calif., concurs: “There’s a rush to install systems before the Jan. 1, 2017, deadline. I currently have cash purchase RFPs on my desk from Lagunitas, Jackson Family Wines and a few wine-storage warehouses.”

It should be noted that rebates have routinely been extended in the past.

Net metering changes
In addition, the utilities want to end net energy metering (NEM), which allows a customer to build one photovoltaic (PV) system to offset the combined loads of having multiple meters instead of one per meter. This is also critical for wineries, which typically have multiple meters on their properties. “There is a big debate going on at the California Public Utilities Commission (CPUC) about the future of net energy metering,” said Gopal Shanker, president of Récolte Energy in Napa, Calif. “This program was and is critical to wineries going solar in such large numbers. The utilities are fighting to end it, but wineries are fighting to keep it going.”

Westcoast’s Gulbransen added a sales pitch that the solar industry is expected to run out of materials this year. “By year’s end, equipment will be going to the highest bidder, so those companies that are interested in solar need to get going now.”

Other interesting developments
Positive developments are occurring, however. These include solar panels over ponds and septic leach fields, plus energy storage.

Because solar panels don’t generate electricity at night, companies and researchers are investigating on-site storage of energy collected during the day.

Jackson Family Wines was the first winery to work with Tesla Energy to pilot onsite stationary energy storage. During the past few years, Jackson has installed 21 battery systems at six of its wineries including Kendall-Jackson, La Crema, Stonestreet and Carmel Road.

These panels also draw electricity from the grid during times of low demand and store it for later use and to smooth out energy spikes in two ways:

Julien Gervreau of Jackson said, “These systems have the capacity to store a combined 4.2 Mw (megawatts)/8.4 MWh (megawatt hours) of energy, which will allow the company to mitigate the costly demand spikes that occur during the most energy-intensive practices in wine production: refrigeration and cooling, compressed air, lighting and process water treatment.

He expects that the Tesla batteries will reduce electricity costs across the pilot wineries by nearly 10%. This will help the company save hundreds of thousands of dollars annually and achieve its sustainability goals.

The systems shift loads, reducing electricity usage costs by shifting the times at which electricity is pulled from the grid (i.e., charging the battery at night, when electricity is cheap and the grid is stable, and using that energy during the day, when electricity is more expensive and the grid is stressed).

They also reduce peak demand spikes and charges by using electricity stored in the batteries to smooth electrical load during times of high demand.

A solar and storage project at UC Davis
In 2016, the University of California, Davis, will install 100 kW of new, highly efficient solar panels on the Jackson Sustainable Winery Building, said Jill D. Brigham, director of the Sustainable Wine and Food Processing Center.

“High concentration of renewable energy sources can destabilize the power grid due to their transient nature (solar: sunrise/sunset/clouds; wind: speed varies). This results in reversal of the flow of electricity in the systems making up the power infrastructure of the community/region/country that weren’t designed for this. The power companies are struggling with this issue, and therefore the California Energy Commission is providing grant money to develop improvements and new technologies,” Brigham said.

Solexel is manufacturing panels in Milpitas, Calif., with the goal of closing the gap. “The manufacturing process uses less silicon, reducing the panel weight and cost,” she said. “It turns out that the weight of PV systems can prevent many companies from installing rooftop solar.”

This generation of panels will supplement the existing 120 kW PV system on UC Davis’ nearby Brewery Winery Food Lab Building. “We will generate more energy than the building uses. Excess energy will be stored in batteries or power other university buildings.”

The solar panels will charge 250 kW of Second-Life lithium-ion batteries donated by Nissan/4R Energy. “These batteries have reached the end of their useful lives in Nissan Leaf electric vehicles. By employing second-life batteries, we keep the used cells out of the waste stream and (if we were to have purchased them) acquire the needed energy storage at a significant cost savings. We will develop a commercial-level controller to manage the batteries and to optimize our output voltage and phase to improve grid stability,” Brigham added.

Separately, the project will generate hot water for the winery fermentor jackets and lab using a solar hot water system. “We also plan to develop a highly efficient, solar-powered ice machine that will provide the chilling for cold water. This cold water will be our sole source of fermentation cooling (no glycol). This project is likely to start in 2016.”

Erlichman of SunlightElectric cautions, however, that wineries have unusual power usage peaking at harvest, suggesting that lithium ion batteries aren’t the optimum way to manage the peak usage periods. “Lithium-ion has some benefits in demand management, but other technologies might be even better, especially in conjunction with solar. We’ve been having ongoing discussions with a number of the larger producers but no implementation yet.”

Floating solar panels
In 2008, Far Niente Winery in Napa Valley got substantial publicity when it installed floating solar panels on irrigation ponds, using acreage that didn’t subtract from valuable grapevines. Now the Sonoma County Water Agency is contacting wineries to sell them floating solar panels. “These will not be installed by the end of the incentives, but that hasn’t stopped Gallo, Coppola, Kunde and a few others from exploring it,” said Gulbransen of Westcoast Solar Energy.

Dale Roberts, principal engineer for the Sonoma County Water Agency, said that the agency sent out a request for proposals on behalf of Sonoma Clean Power for solar developers to develop floating solar photovoltaic systems atop agricultural ponds.

“This RFP (request for proposal) was sent out because the Water Agency and Sonoma Clean Power received proposals about one year ago with favorable power pricing for a similar RFP inviting proposals to develop 12 mW of floating solar PV atop water agency recycled water storage ponds. As a community that values open space and agricultural land, the surface of ponds is an underutilized asset. Floating solar projects help deploy renewable energy on otherwise unusable acreage. Once proposals are received, the water agency will turn the proposals over to the ag pond owners (mostly wineries), so they can begin discussions/negotiations with the proposers to develop their own floating solar PV projects.”

However, Erlichman of SunlightElectric said that floating solar power may be unwise. “I believe there’s a few good reasons Far Niente is the one and only floating solar power system at a winery. The voiding of the panel manufacturer’s warranty (the “marine environment” exclusion), the challenging access for cleaning and maintenance, the safety risks of servicing with all that water around them, the potential challenge of having to keep the pond full otherwise the panels might crash together, and the fact that the guys who did Far Niente’s project—SPG Solar—are out of business suggest we won’t be seeing too many of these in the future.”

Erlichman thinks that a better solution is installing the arrays on the pond berm, as his company did at Trefethen in 2007, and/or pole-top arrays at the end of vine rows, like those it installed at Keenan in 2006.

He added, “Though this is heresy and we never suggest it, quite a number of wineries have volunteered weak-performing portions of their vineyards for arrays, and we’ve done the math with winery CFOs. It can be better economics for making electricity than growing grapes. We’ve done quite a number of such projects.”

Erlichman is also working with the Napa Department of Planning, Building and Environmental Services on developing standards and updating the codes to allow solar panels on septic fields. “Having done three of these (Frog’s Leap in 2004, Staglin in 2007 and Cliff Lede in 2011), we’ve learned a lot about what works and how to address the county’s genuine concerns about how to use a septic field for solar and ensuring that it doesn’t interfere with the operation of the septic system. Napa expects to update the codes in the spring of next year,” he said.

Print this page   PRINTER-FRIENDLY VERSION   »
E-mail this article   E-MAIL THIS ARTICLE   »
Currently no comments posted for this article.