This article is from the January/February 2004
issue of Practical Winery & Vineyard Magazine. Order current
or back issues here.
Wineries in the U.S. (especially in California), have been installing
solar energy systems at an ever-increasing rate in recent years.
While the energy efficiency and environmental benefits of solar
energy have long been known, the initial cash outlay for a solar
system has deterred many potential customers. But solar energy
advocates and installation companies have capitalized on current
state and federal incentives to make solar energy more attractive
Mount Eden Vineyards
Mount Eden Vineyards (Saratoga, CA) installed a 20 kilowatt (KW)
capacity photovoltaic (PV) solar system in October 2003. (For
comparison purposes, the average size for a home solar system
is 2.5 KW.) Working with Akeena Solar (Los Gatos, CA), the 14,000
case/year winery chose a $185,000 system.
Mount Edens system was installed on a hillside near the
assistant winemakers home, and includes 136 panels of 185
watts each (known as modules), and nine Sunny
Boy inverters. Inverters work to turn the energy current,
generated as DC current through the solar modules, to AC current
for use in the winery.
Some systems are installed with a single inverter with the same
capacity as the entire system. Others employ multiple inverters,
whose capacity adds up to the total system capacity.
At Mount Eden, the winery and solar company agreed on multiple
inverters. Although it was slightly more expensive, we took
this approach because with multiple inverters, failure of one
will not affect the others, and they operate at a slightly higher
efficiency over a single inverter, says Barry Cinnamon of
At its peak (during long, sunny summer days),
the Mount Eden system will generate 20 KW of power. Annual energy
output is a factor of sunlight hours, sun intensity, orientation
of the panels, equipment output, and efficiency losses during
power transmission or periods of down equipment.
Akeena, like other solar system installers in this report, works
closely with client wineries to assess not only the amount of
energy needed to serve the winery, but the confusing maze of energy
rebates, tax credits, and other financial incentives offered by
local and state energy programs.
We developed a detailed economic analysis of the system
for Mount Eden, reports Cinnamon. Mount Eden is on
Pacific Gas & Electrics (PG&E) A6 rate, which is
a small, commercial Time of Use (TOU) rate. TOU rates are terrific
for PV systems because they generate additional energy credits
during summer afternoons exactly when PV systems create
their greatest output. Mount Eden has an annual electric bill
of about $7,000. We expect that their bill will drop to $55
Incentives for commercial PV systems are significant. The California
Energy Commission (CEC) offers up to $4 per kilowatt-hour (KWH)
in rebates for a commercial business that applied before June
2003; a $3.80 per KWH rebate for businesses that filed before
December 31, 2003; and a $3.60 per KWH rebate after January 1,
2004. As its funds run out, the CEC reduces the rebate by $.20
per KWH every six months.
For 30 KW and smaller systems, the California Public Utilities
Commission offers a rebate of up to half the net purchase cost
of the system. The federal government offers an investment tax
credit of 10% on the remaining cost of the system installation
after the CEC rebate. The state of California offers its own tax
credit (15% until the end of 2003 and 7.5% thereafter).
There is a depreciation credit on a PV system from state and federal
governments. Some PV systems are set up to feed excess power back
to their energy company, making the winery a power producer that
is paid for the power it generates.
With Akeena helping on all of the state and federal paperwork,
Mount Eden expects the $185,000 system to cost only $90,000 in
its first year, and to pay for itself within five to seven years
Vino Noceto Winery
Vino Noceto Winery (Plymouth, CA) installed a 10 KW system in
the spring of 2002. The system consists of four 2.5-KW panels
and four Sunny Boy inverters. An attractive aspect of smaller
multiple inverters like the Sunny Boy is that they are mass-produced,
making them quicker and easier to replace or repair if they go
The 200-ton capacity winery is at 1,500-foot elevation in the
Sierra Nevada foothills, and the panels were installed facing
southwest for good sun exposure. They are mounted on a sloped
(15%) roof. With only four relatively lightweight panels, the
winery did not have to reinforce the roof before installation.
The system cost was $110,000, but the winery received an immediate
state rebate of 40% of the installation costs. Owner Jim Gullett
expects payback in six to seven years, and may install up to 50%
more solar capacity in the future.
we installed solar, he reports, during harvest, we
paid an average energy bill of over $1,000 per month. Since putting
in solar, our bills during bottling average about $100 to $300,
and other months the bill swings down from $100 past zero to as
low as $50.
In a 12-month period from May 2002 to May 2003, the winery saved
$9,000 on its PG&E utility bills, going from annual spending
of $13,800 to just $4,800.
Sierra Vista Winery
Inspired by an open house at nearby Vino Noceto, John and Barbara
MacCready of Sierra Vista Winery (Placerville, CA) installed a
solar system in September 2003.
We saw the Vino Noceto installation and asked Premier Power
(El Dorado Hills, CA) and another company to give us quotes. We
were committed to the project if we could afford it, John
MacCready says. We also bought a new Europress to replace
our old press, and those two projects are significant for a small
winery with no deep pockets in a less-than-great economy.
The gross cost of Premier Powers system was $100,000. Rebates,
tax credits, and depreciation reduced the actual out-of-pocket
cost to less than 70% of the gross cost. The solar provider helped
the MacCreadys with paperwork for the rebates and tax credits,
which were provided in the initial quote. (See Table II for details.)
Vistas system is 14.4 KW, installed on the winery operations
building at a slope of 1:12, with half of the roof facing southeast
and the other half northwest. The panels are Sharp 185 modules
as at Mount Eden, with Sunny Boy inverters, and they cover 1,500
square feet of the roof. Just the presence of the panels shading
the roof of the building should reduce summer cooling costs by
as much as 10%.
At an elevation in the Sierra Nevada mountains of 2,800 feet,
the winery can expect few problems with fog or other sun occlusion.
We see fog at the winery once or twice a year, but see fog
in the valleys around the winery quite often, reports MacCready.
Accounting for factors such as fog is important in helping determine
what type of solar modules to install. There are different
types of modules for different applications, explains Deborah
Millhollin of Premier Power. Certain modules are suitable
for areas with fog; others are better for very warm temperatures,
and others for cool temperatures.
The Sharp solar panels at Sierra Vista have a life expectancy
of up to 30 years and are guaranteed for 25 years. Wineries should
check warranties with their solar energy installers, since it
is a contingency of some state and federal credit/rebate programs
that the systems be under warranty and/or service contract for
at least the first five years after installation.
Sierra Vista Winery bottled 8,659 cases of wine in 2002, and crushed
126.5 tons. The building is well-built and insulated, needing
no reinforcement to install the solar panels.
Premier Power tied the Sierra Vista system into the electrical
grid for net-metering. Under the net metering system,
once the winerys own energy needs are met, it can funnel
energy back to its utility, PG&E, during peak efficiency times
such as sunny summer days.
The Interconnection agreement we provided means PG&E
now considers the winery to be a power producer and not a consumer.
Sierra Vista will pay a utility bill annually, paying only the
difference between what it produces and what it uses, adds
Markus Bokisch is using solar energy to power vineyard irrigation
in Clements, CA. A 7.5 KW system has three inverters, provided
by Renewable Technologies, Inc. (RTI) of Sutter Creek, CA. The
vineyard is on the net metering system with PG&E.
Installed on a shop roof at Bokischs vineyard, the system
sends about 50 KW per summer day to the power grid. At night,
35-horsepower pumps pull energy off the grid to water the vineyards.
Right now, were producing about 35% of the energy
we need to power the irrigation for 60 acres, our shop, and a
home, Bokisch reports. Well need a 22 KW system
for 100% of the power we need in summer, 50% in winter. We will
install more panels and hope to be up to 22 KW by spring 2004.
The modules are on a 22% incline, in an area with low dust, and
they achieve about 78% average annual efficiency. To keep the
panels efficient, simple maintenance with sprinklers to rinse
dust and dirt is planned.
Bokisch hopes more farmers will get into solar. Indeed, he has
seen enough interest from fellow growers that he finds himself
guiding informal tours of his solar energy system and educating
The Clear Skies Group is a renewable energy installer located
in Long Island, NY, with offices in California. CEO Ezra Green
has been trying to get Long Island vintners interested in solar
energy, but is hampered by New Yorks net metering program
which does not allow power providers to bank energy
savings they feed back to the grid for future use.
We do a lot of farms in surrounding states, and are beginning
to work with small wineries in California, he reports. Small
farms and businesses are the perfect candidates for solar use.
The process for getting started is very simple. A grower need
only collect 12 months of utility bills, then fax or mail them
to us. We give a working proposal recommending system size, potential
savings, and a list of components wed supply. Then we visit
the site and walk the owner through the process.
Clear Skies specialty has been working with water companies
like World Water in New Jersey, designing systems to power irrigation
and water management. Flatbrook Farms in Montague, NJ, is an example.
Clear Skies installed three systems (10, 8, and 4 KW for a total
22 KW system) at Flatbrook.
solar panels are Sharp brand (Clear Skies uses mass-produced name
brands for cost reduction and ease of repair or replacement),
with Sunny Boy inverters, mounted with galvanized piping set in
12-inch pilings. Green describes the panels as single crystal
panels, which have the highest ratings for efficiency of energy
collection. Power flows through the inverters, converts to AC
power, and then goes into the circuit breaker panel for Flatbrooks
Green and his team monitor new systems closely at first. For
the first three weeks, we monitor the system weekly. Then we come
every two weeks for the next six weeks; then every couple of months
for the next six months. There are very few problems with solar
energy systems, he reports.
Solar energy systems require little to no maintenance, Green notes.
Clear Skies systems use no moving parts.
Another Clear Skies customer, Rex Farr in Calverston, NY, is participating
in a pilot program to bring renewable energy to farms currently
dependent on fossil fuels. Farrs 30 acres of vines will
get a new drip irrigation system powered by solar energy.
By shutting down one diesel generator, Green states,
you are eliminating tons of pollutants from the air. If
we change our energy-producing methods, the effect on the environment
will be profound.
Seavey Vineyard & Winery
Seavey Vineyard (St. Helena, CA) had a 10 KW system installed
by Renewable Technologies in February 2003. The 3,500 cases/year
winery installed 64 modular panels and four inverters. Half of
the modules were installed on a shed with a south-facing roof
and half on a custom-designed free-standing shade structure.
The choice of the shed was an aesthetic and safety decision,
says Will Seavey, son of owners Mary and Bill Seavey and the driving
force behind their switch to solar energy. We wanted to
keep the winery building looking nice for visitors, and with so
much activity around the main building (children often play there,
for instance), any kind of objects could have landed on the roof
and damaged the modules.
But because electricity loses force over distance, the fact that
the power had to travel more than 500 feet to the appropriate
meter presented a challenge. Darryl Conklin of RTI advised and
installed transformers to boost energy as it traveled
down a buried power line connecting the solar system and meter.
The voltage is kept high, but transformed back to
low voltage just before arriving at the meter. Thus the energy
gets back to the meter at its full power rating.
the common method of multiplying the number of kilowatts in its
system by the average number of hours of sunlight per day, Seavey
estimates the solar energy system produces an average of 55 KWH
per day. It produced up to 75 KWH of power on a long summer day,
and they expect 35 to 40 KWH on cloudy winter days.
Seavey notes his monitoring of meter readings indicates the solar
system provides two-thirds of the winerys energy needs.
During the summer, the system has saved the winery about $450
per month, and savings in winter will be about $170 per month.
The winery also received $40,000 back from the state rebate program
on initial installation costs. We estimate financial payback
in five years, concludes Seavey.
The new Domaine Carneros (Napa, CA) Pinot Noir production facility
is one of the largest projects of energy efficiency ever attempted
in the worldwide wine industry. When planning began on the winerys
new 23,000 sq. ft. addition, it was decided to aim for maximum
Overseen by Eileen Crane, president, Sid Lipton, (owners
consultant), and Wright Contracting (general contractor) [Santa
Rosa, CA], the buildings grand opening was on June 21, 2003
(the summer solstice). The construction included work from over
40 subcontractors and suppliers. PowerLight of Berkeley, CA, was
the solar installer.
The 120 KW PowerGuard system consists of 688 lightweight solar
panels mounted flat on the buildings rooftop, and a single
120 KW inverter. The system initially cost $850,000, but the winery
immediately claimed a PG&E rebate of $425,000. PowerLight
projects a maximum potential of 90% efficiency from the system,
which is expected to generate 40% of the winerys energy
Maintenance of the solar panels consists of washing them off once
or twice each month. Projected payback on the system is just four
years, factoring in all tax credits, accelerated depreciation
credits, the amount of power generated and its attendant utility
savings, and the energy efficiency of the building itself.
In addition to 2-inch thick solar panels covering the roof and
giving some sun protection, the winery installed R35 roof insulation.
Rigid foam insulation on the exterior face of concrete block walls
contributes to a total eleven inches of wall and insulation thickness.
Another feature of the buildings energy efficiency is the
Sunpipe® Daylighting System. Instead of installing traditional
skylights which offer unfiltered light through large openings
in the roof (thus allowing heat in, which is counter-productive),
Lipton did some Internet research and found the Sun Pipe Company
in Elgin, IL. Greg Miller is Sun Pipes owner and co-inventor
of the system.
Sun Pipes pipe in daylight from above the roof
using aluminum pipes with a super-reflective interior, explains
Miller. Fifteen 21-inch diameter, 5-foot long Sun Pipes
were installed between solar panels on the roof to illuminate
the fermentation cellar with diffuse daylight. The diffusion occurs
at the bottom of each pipe (18 feet above the floor) via a white
diffuser dome which glows with however much daylight is available.
The greatest category of energy savings is not electric
lighting, notes Miller. Its HVAC savings. Sun
Pipes remove only 1/10 of the roof insulation that skylights remove,
and they introduce comparatively little solar heat gain. This
translates into massive HVAC energy savings for air-conditioned
The greatest financial reward is the effect that daylight
has on employees. Fewer sick days, fewer vision and attention-related
accidents, and increased productivity are some of the human benefits
of daylighting a workplace.
Mike Davidson of Industrial Refrigeration and Process Piping (Healdsburg,
CA) worked on energy-efficient refrigeration for the facility.
The industrial refrigeration system installed at Domaine
Carneros consists of two 20-ton (a system designed for a future
20-ton compressor) open-drive, reciprocating compressors with
external capacity control, explains Davidson, connected
to a flooded glycol chiller providing cold glycol to the winerys
new fermentation tanks and barrel storage room.
This system uses many efficient components, but two of the
primary benefits of the newly installed chiller system are the
flooded glycol chiller and operation of the programmable logic
controller (PLC) installed on the package.
The flooded glycol chiller is significantly different than
a conventional direct expansion-fed shell and tube chiller. Flooded
chillers operate based on natural convection due to the difference
in densities between the solid column of refrigerant liquid feeding
the chiller and the gas/liquid mixture being boiled by the glycol
(heat is absorbed by the glycol returning from the system).
Some of the energy-efficiency benefits of the flooded glycol chiller
include: substantially higher heat transfer coefficients; more
efficient use of the heat exchanger surface; a wider range of
operating temperatures; and the system can obtain a closer refrigerant-to-glycol
approach temperature (as close as 3†F), which increases the compressors
capacity and reduces its horsepower requirement.
A programmable logic controller (PLC) installed on the package
provides a measure of energy efficiency, adds Davidson. This
method of compressor loading and unloading provides precise control
without over- or under-shooting the target temperature, which
yields a much smoother system operation and reduction in electrical
usage through reduced demand and use charges.
Crane is proud of the finished facility. The installation
marks a significant milestone in Domaine Carneros continuing
efforts to achieve sustainability in the production of premium
Ridge Lytton Springs Winery
Solar energy panels were installed at Ridges new Lytton
Springs 18,000 sq. ft. facility (Healdsburg, CA) in September
2003. The new facility will produce red wines, predominantly Zinfandel,
and like Domaine Carneros, was designed with energy-efficiency
in mind. (See January/February
The 66 KW PowerLight system contains two panel arrays on two slopes
of the rooftop. The roof is pitched at 17 degrees and 35 degrees
on slopes facing due south. The panels were installed a few inches
above the roof, thus doing double the cooling work by blocking
sun and by allowing cooler air to circulate along the surface
of the roof.
Ridges system has two 30 KW inverters. It is expected to
generate 80,000 KWH/year and was set up for net metering so that
Ridge can sell excess power to the utility grid at peak times.
Mark Vernon, chief operating officer at Ridge Vineyards &
Winery, anticipates that the winery will use most of the energy
it produces, given the size of the facility, but says its
a bonus that the winery will be in need of the largest amount
of energy at the same time that it is producing the most
in the summer and harvest months.
PowerLight helped Ridge file all its paperwork for incentives
and net metering. The winery recouped 50% of the initial cost
of the system in rebates, and is eligible to receive up to 25%
more of the cost back in tax credits from the state and federal
governments next tax year.
Evergreen Valley Winery
Evergreen Valley (Luthersburg, PA) is uniquely located to use
solar energy. Owners Mark and Lorraine Gearhart planted a 10-acre
vineyard in a reclaimed strip coal mine in Pennsylvania Amish
Country, where little electricity service is available.
The winery is not connected to an electric power grid. There
is no cash incentive program in our area to install solar or wind
power, and a substantial power company charge to even hook us
up, says Gearhart. So we opted out totally and built
our winery and home here to require no outside power.
winery building is on a ridge, with solar panels installed facing
south at a 45-degree angle. In 1991 when he established the vineyard,
Gearhart installed one 40-watt solar panel and a windmill. In
1997, six 100-watt solar panels were added. In 2003, a second
windmill and six more panels brought the total energy production
to 1.25 KW. Gearhart, a licensed professional engineer, aims to
eventually increase the solar energy capacity to 2.5 KW.
Since there is no electricity grid to accept power, the winery
uses 18 200-amp, 6-volt golf cart batteries to store energy. The
batteries can hold a combined total of 20 to 25 KW of energy.
The six bearing acres of vineyard yield about two tons each. The
winery has crushed up to 12 tons per year using an electric crusher
and a Willmes bladder press. Solar and wind power meet all the
winerys crush, bottling, computer, cash register, and lighting
needs, as well as powering Gearharts home.
We dont have the large numbers of installed panels
that others do, but without a tax incentive, we have accomplished
a totally self-sufficient business on that tiny amount of energy
by being very efficient in the way we use what we do have. Were
about wine first were big on things like battery-powered
forklifts and other labor savers.
Stargazers Vineyard (Coatesville, PA), a 2,000-case winery with
14 vineyard acres in southeastern Pennsylvania, is on an electrical
grid, so the winery was able to take advantage of public utility
rebates, and state and federal tax credits to defray some installation
costs. Accelerated depreciation credits mean the winery will see
payback on their system in 15 years.
Owners John and Alice Weygandt strive to keep their operations
and home green. The winery, built into a hillside,
requires no additional heating or cooling. Their nearby home is
a passive solar envelope design. Rainwater collected
in cisterns from the winery rooftop is used for cleaning in the
A 30-panel solar energy system will generate up to 4800 KWH/year
of power for electrical needs. The BP solar panels are on the
south-facing winery roof, which has a 26† slope.
Prior to going solar, the Weygandts purchased electricity from
The Energy Cooperative, a Philadelphia-based nonprofit electrical
supplier which purchases solar energy from residences and businesses
who become renewable energy producers. Now Stargazers Vineyard
has become an energy producer, and plans to sell any excess energy
produced by the solar system to the Energy Cooperative.
Rodney Strong Vineyards
Installation of a 766 KW system from PowerLight at Rodney Strong
Vineyards (Healdsburg, CA) in October 2003 became the largest
solar energy installation in the wine industry. Installed on a
south-facing roof of the winerys 100,000 sq. ft. barrelhouse
at a 5† slope, 4,032 panels with three large inverters make up
the system. The panels are fixed, but mounted a few inches above
the roof to give both shade and cool airflow along the roof.
Tobin Ginter, chief financial officer, was instrumental in crunching
the numbers and pushing to install solar energy. He reports the
gross cost of the large system to be about $4 million, but the
net will be only half that, and payback will take about nine years.
The system should supply most of the 600,000-case winerys
power needs, averaging 250,000 KWH per month of energy output,
and peaking during harvest at up to 420,000 KWH per month.
PowerLight also installed new lighting at Rodney Strong Vineyards
for further power savings. Over 400 high-efficiency, linear flourescent
fixtures and lamps with electronic ballasts were placed throughout
the wine production and case good storage areas. The system includes
sound and motion sensors so that only occupied areas are illuminated.
The new lights generate less heat than older lighting at the winery,
reduce lighting electric demand by about 500,000 KWH per year,
and deliver light at a higher color rendering index (CRI), which
matches natural light closely, increases visual acuity, and makes
the lighting more comfortable to the human eye.
Solar electrical systems have never been more suitable to
our industry, notes Tom Klein, chief executive officer.
The combination of solar technology improvements with customary
flat-roof winery buildings and their sunny locations, have made
renewable energy more commercially viable.
Never a better time
The wineries and renewable energy companies in this report all
stressed that now is the time for wineries and vineyards to get
solar or other renewable energy installed if they can.
State and federal incentives have never been better. But state
incentives are beginning to diminish as funds, such as the CEC
Renewable Energy Program, run out with no sign of replenishment
from the financially-depressed state of California. In addition,
the California tax credit reduces by half in 2004.
Darryl Conklin of Renewable Technologies, Inc., (RTI) has appeared
before state committees with proposals and recommendations for
keeping and increasing incentive programs. A fierce advocate of
renewable energy, he fights not only to educate government officials
but the general public also. RTI has built a special trailer containing
working examples of wind and solar power to take to schools and
businesses for demonstrations.
Its a continuing fight for education and funding,
Conklin says. We have to fight the utilities also. PG&E
wrote legislation to charge net-metering energy producers a nickel
per kilowatt to send power to the grid with the argument that
PG&E built the grid in the first place. Luckily that got defeated.
At a March 2003 hearing before the California Energy Resources
Conservation and Development Commission, Conklin recommended that
the commission, from its budget, send at least $1.35 million annually
to the Renewable Resources Consumer Education Account, and $6.08
million annually to both Emerging Renewable Resources and to the
New Renewable Resources Account.
Conklin also seeks better oversight of utility companies to ensure
that renewable energy producers are getting what they should from
net metering and other systems, and that monopolies dont
strangle small businesses as renewable energy producers.
He also encourages regulations that dont choke renewable
energy systems and eat up allocated funds which could otherwise
go to encourage more consumers to become renewable energy producers.
Exploring solar energy
Wineries and growers who consider using solar energy should consult
their state renewable energy advisory agencies (see Resources
at end of this report), and work closely with the solar provider
they choose to file all paperwork required and meet all deadlines
to receive rebates, tax credits, and depreciation incentives.
They should also carefully review how net-metering works within
their local utility system if they intend to produce enough power
to feed back to the power grid.
Actually receiving money back on a solar installation depends
on careful, informed planning beforehand.
Cinnamon, Akeena Solar,
605 University Ave., Los Gatos, CA, 95032; Tel: 408/395-7774; Fax:
Group, 757 Harrison St., West Hempstead, NY, 11552; Tel: 877/825-3374.
IRAPP, 1160 Industrial Rd #2, San Carlos, CA 94070; Tel: 650/595-0665;