Insulated copper piping brings glycol
from Williams Selyem’s solar collectors
down to four, 175-gallon storage tanks
with internal heat exchangers (1). The
tanks feed the preheated water into the
winery’s propane-fueled water heater (2),
reducing the amount of propane needed
to keep water hot, or to heat water in the
propane tank for winery needs.
An external heat exchanger uses
the heated glycol from the solar thermal
system to heat water for the hot
water loop at Kunde, boosting the
temperature of hot water going to
the boiler. Water can remain hot to
200°F in the storage tank for up to
three days (it loses about 1°F per
hour if no new hot water is introduced).
The solar thermal system, at
its peak production, should be able
to generate up to 4,000 gallons of hot
water for daily use at Kunde.
“The system’s efficiency is highly
dependent on the amount of solar
radiation, and the daytime temperature,”
Fish reports. “On hot, sunny
days, the storage tank will reach
200°F by early afternoon if we start
from 60°F. On cooler, overcast days
it may only reach 80°F to 100°F.”
Hot water from the boiler is piped
to Kunde’s caves for barrel washing,
and to the bottling
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line for sterilization.
Early morning bottling runs take
maximum advantage of the hot water
generated the previous afternoon.
Fish planned that Kunde personnel
try to do barrel washing on days when
hot water is not needed to sanitize
the bottling line, or in the afternoon
when the solar thermal system is at
top efficiency. The winery is researching
the use of a steam generator as a
method for sanitizing the bottling line
and barrel cleaning. Pre-heated water
from the solar thermal system could
be used to feed the steam generator,
cutting hot water use significantly.
Kunde’s solar thermal system also
pre-heats domestic hot water for the
winery building, and a high-efficiency,
tank-less, hybrid hot water
heater was installed to boost the
solar-heated water when necessary.
Solar thermal system maintenance
is performed by washing down the
roof panels to remove dust two to
three times per year, checking the
glycol level every other year, and
periodically inspecting the system
for damage or leaks.
Williams Selyem Estate Winery
The new Williams Selyem Estate
Winery center on Westside Road
outside Healdsburg took three years
to complete, and while crush and
primary fermentation are still performed
at nearby Allen Ranch, the
new building contains barreled wine
and case goods, a bottling line, and
visitor center.
A 54kW solar PV system was
installed by One Sun (Graton, CA) as
two carport rooftops (one on the west
side of a parking lot, and one on the
east side). 226 PV panels are fixed at a
4-degree tilt, and seven string inverters
convert DC current produced by
the panels to AC current for use in the
winery. The PV system is expected to
power 25% to 35% of the facility’s electrical
needs, and earned a 30% federal
tax credit and PG&E’s CSI solar PV
rebate.
A solar thermal system, installed
by SunWater Solar (Richmond, CA),
was activated in July 2010. The system
components on the outside of the
building are:
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- 14 Heliodyne Gobi 408 collectors
facing due south, with 448 square feet
of collector area;
- 1.5-inch copper piping (L piping)
with Armaflex neoprene insulation
(3/4-inch wall) jacketing on the
exterior.
Inside the winery, the system has:
- 4 Rheem 175-gallon solar hot
water storage tanks with heat
exchangers;
- 1 multi-speed solar pump;
- 1 mixing valve (controlling hot
water temperature to prevent scalding);
- 1 Wi-Fi solar differential control
(interface with online monitoring
capabilities);
- 1 small expansion tank (5 to 10
gallons, to hold excess glycol, which
expands with heat, so that it will
not exceed the capacity in the pipes
and collectors).
The 14 collectors mounted on the
winery roof absorb the sun’s rays,
heating the glycol that circulates
between the collectors and the four
water storage tanks in the mechanical
room. The heated glycol travels
through piping from the collectors to
the heat exchangers inside each solar
hot water storage tank.
As the heated glycol passes
through a heat exchanger, the heat
is transferred to the water stored in
the tanks. A pump pushes the cooled
glycol back up to the collectors. The
solar water tanks feed the winery’s
propane-fired water heater with
solar pre-heated water, significantly
reducing propane consumption.
The solar differential control is the
“brains” of the thermal system. It
turns the pumps in the solar thermal
system on and off, and also logs system
data. Because the control utilizes
Wi-Fi (wireless Internet connectivity),
winery operations can view system
data anytime, on any computer
that has an Internet connection.
Hot water produced by this system
is used for barrel washing,
wash-down of tanks, equipment,
and floors at the facility, and bottling
line/bottle sterilization before
filling. It is also used for heating
barrel storage rooms when needed,
and for sterile cleaning (including
four commercial dishwashers in the
visitor center).
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