Q: Is
solar hot water a good investment for me?
A: The potential savings on water heating bills are affected
most by the type of fuel you are using to heat your water
and the number of people in your home. If you are heating
hot water for two or more people and you heat water with electricity,
natural gas or oil, then you owe it to yourself to look into
solar water heating; it could be a great investment for you.
Q: What is a solar water heater and how does it work?
A: A solar water heater uses the sun's energy rather than electricity,
gas or oil to heat water, thus reducing your monthly utility
bill. When installed properly, solar water heaters are more
economical over the life of the system than heating water
with electricity, gas or oil. Most hot water systems are designed to preheat water before
it enters a conventional hot water heating system. The four
parts of the system include a collector, a pump, a heat
storage tank and a differential thermostat.
Q: Will I run out of hot water?
A: No, because the temperatures from a solar water heater (reaches
and exceeds 140F) is much higher than a conventional water
heater (120 to 130F). Therefore, your existing water heater
works very little compared to not having a solar water heater
installed. Additionally, your existing system serves as
backup to the solar system ensuring that you will continue
to have as much or more hot water than before. On top, you
will be able to get more years out of your existing water
heater. Typically on LI a well designed system can provide
over 65% of your annual hot water needs.
Q: Where will the panels be installed?
A: The best orientation for a solar hot water system is on a
south-facing roof, however roofs that face east of west may
also be acceptable, even though they will require more collector
area. Flat roofs also work well for solar systems, because
the thermal collectors can be mounted flat on the roof, facing
the sky or on frames, tilted toward south, at the optimum
angle. If a rooftop cannot be used, your solar hot water system
can also be installed on a ground anchored rack or trellis.
Q: How does it work in cloudy weather or if there’s
no sun for several days?
A: The sun must be “out”
in order to gather all the energy required, however, the
backup system always insures that you have plenty of
hot water. Running out of hot water is not an issue for
solar users. In fact, with the lowest cost, you can
feel free to use hot water lavishly.
Q: Do I have to change my habits to use a solar
water heater?
A: No. Solar water heaters are always installed
in front of your exisint hot water system to ensure that
hot water is available at all times. Also, your solar system
will be more effective if your use of hot water is spread
more evenly over the week. For example, if you use hot water
for laundry, instead of washing seven loads of clothes in
a single day, wash one load each day. This will reduce the
amount of backup energy required for your solar system.
Q: How much does a solar water heater cost?
A: On LI, an installed solar water heating system can cost
anywhere from $5,500 to $9,500. Why the large range? System
cost depends upon certain variables, such as the following:
- Size of family to be served
- Size and type of solar system
- Type of financing available
- Type of roof on which the collector is to be installed
- National grid rebates for gas users
- Building code requirements
Solar water heating is economically competitive with electrical,
oil or natural gas heating.
Q: Does government offer any financial incentives?
A: There are federal and New York State tax credits available.
Q: What kind of a solar collector should
I buy?
A: There are basically two types of solar collectors available
for solar water heating. The first is referred to as a flat-plate
glazed solar collector. The second is the evacuated tube.
Both collectors are mounted in a fixed position throughout
the year and do not track the sun as do some collectors that
are used primarily for high-temperature applications.
A basic flat-plate collector consists of a metal enclosure,
an absorber plate and flow tubes, insulation, and a glass
covering. Flat-plate collectors can be 2 to 4 feet wide, 5
to 12 feet long, and 4 inches thick. The absorber takes in
the sun's energy, which is then transferred to the fluid flowing
through the tubes attached to the absorber.
To reduce heat losses, all flat-plate collectors generally
have insulation behind the absorber plate and a glass cover
on the front, facing the sun. The best cover material is tempered
glass of low iron content. Some edge insulation inside the
enclosure box is also necessary.
The absorber plate is made of copper and is coated with a
black chrome or nickel material called a selective surface.
This surface greatly enhances the collector's ability to capture
and retain solar energy. Some manufacturers also use black
paint as an absorber coating.
The Florida Solar Energy Center conducts a federally mandated
program of collector testing and certification. All collectors
suitable for Federal Investment tax credits require the
Center's certification label.
A document entitled Thermal Performance Ratings, available
from the FSEC Public Information office, contains the performance
rating for each solar collector certified by the Center. The
document also provides an approximate efficiency-per-dollar
comparison method you can use as a guide for rejecting inefficient
or overly expensive collectors.
Q: Since there are several different types
of solar water heating systems, how can I compare their performance?
A: Your solar professional should provide the necessary engineering,
documentation, and analysis to aid in your selection.
Q: What is the proper orientation of the
solar collector?
A: Collectors should be mounted on an un-shaded area of a south-facing
roof. They can face up to 45 degrees east or west of south
without a significant decrease in performance. Additional
equipment can be added to respond to the needs of homes
whose roof is closer to east and west.
Q: How do I decide which solar water heating dealer to contact?
A: Compare price, efficiency, service
options, dealer reputation and warranties. Ask the solar dealer
for a list of previous customers, and talk to them. Ask the
owners about performance. Does the system provide sufficient
hot water? Was it affected by last winter's freeze? Inquire
whether service has been necessary and if it was satisfactory.
Ask about the warranty offered and read it carefully. A reputable
dealer/installer will normally repair or replace a system
component that malfunctions in the first three years if the
problem is caused by faulty materials, workmanship or installation.
The quality of installation can
radically affect the reliable operation of a solar system.
Installers should be licensed to install solar water heating
systems. Installers should have a local plumbing license,
which authorizes them to install solar residential hot
water systems.
The contractor should be a member
of the Long Island Solar Energy Industries Association and
agree to abide by their code of ethics. As with other trades,
your local Better Business Bureau can reveal any service or
installation complaints against a vendor.
Q: Are solar water heating systems reliable?
A: Properly designed and installed systems with glass-covered
collectors should perform well for more than 20 years. Controllers,
like other electronic devices, may require servicing during
the life of the system, and the pump and hot water tank
may have to be replaced in the life of the system. Since
conventional water heaters have the same expected lifetime,
water tank replacement costs are not regarded as unique to
solar energy systems.
Normal maintenance consists of checking pipe insulation,
roof penetrations and collector mounting, pump operation and
tank flushing. The latter is also recommended for conventional
water heating systems, as is periodic replacement of the water
heater sacrificial anode rod.
Many installation firms provide yearly maintenance checkups
of their solar systems similar to annual air-conditioning
system maintenance programs. These can be beneficial in extending
the life of the system and ensuring optimum performance.
Q: What other ways are there to save on water heating bills?
A: Besides simply using less hot water,
the following strategies are suggested:
- Wash clothes in cold or warm rather than hot water.
- Wrap extra insulation around the existing tank and insulate
a few feet of the hot water line near the tank.
- Install an automatic timer so that the heating element
comes on only during certain hours of the day. This may
be cost effective if hot water is needed only for a few
hours per day.
Finally, in a one-tank solar system, it's a good idea to
have the back-up element controlled by a timer or manual on/off
switch to keep it from coming on during the day. This strategy
allows the solar system to produce all the hot water without
the back-up heater being activated.
Timers may become very attractive if peak-load pricing of
electricity is introduced. In that event, electricity would
be priced at a much lower rate during certain hours of the
day than at other times. Peak-load pricing is being evaluated
by many electric power companies.
|
