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There are many different ways to enhance your energy self-sufficiency.
No matter which way the sun is harnessed, there is an
environmental benefit. But economic benefits can vary considerably, so
it is
important to examine which ones pay for themselves the quickest in
terms of
energy cost savings.
Also, some systems are more complicated to own and operate,
while others operate in a manner almost invisible to the owner. Here is
a look
at some of the strategies that can be used and how they can benefit the
owner.
 Daylighting
Do
you
find that you are turning on the lights in your house even during the
day? A daylighting system can bring in natural sunlight into dark or
windowless spaces inside a home or office. Unlike a skylight, which
brings a harsh sunbeam that moves across the room, daylights add
diffuse light that is filtered to remove ultraviolet and infrared light
for soothing, natural illumination.
Solar Hot Water
Heater
A properly configured solar water heater is an excellent
first step to saving money and saving energy costs. Operation is
simple,
maintenance is low, and the payback is quick. Depending on the local
cost of
the existing energy source (often electric), the local climate, and the
tax
incentives, the system can pay for itself from savings in three to
eight
years.
The components such as the collectors are typically waranteed for ten
years and
have a practical lifespan that exceeds that by many times. Water
collectors are far more efficient at converting solar energy than
photovoltaic
collectors.
Hybrid Car
Despite the current popularity of hybrid cars, these are not
the most cost effective means of energy savings. When you compare the
cost of
the added electric systems to the gas mileage improvements, the
payback time
is around ten years. Not much worse than solar water heaters, but a ten
year
old car is near the end of its life. The biggest advantage to hybrids
is
environmental – the energy it replaces is from gasoline, which is one
of the
dirtiest energy sources. In today’s hybrids, even the electricity
ultimately
comes from the gasoline engine. The total energy savings is modest but
still
justifiable for the added cost.
The next generation of hybrids will be plug-in hybrids. With
these cars you can plug them into the power grid when they are not
used. When
these vehicles are used for short trips around town, such as commuting,
both
the savings and the environmental impact will be greatly enhanced.
Stand Alone
Photovoltaics
Photovoltaic panels generate electricity
and can be used
anywhere electricity is needed. In some remote locations, the electric
grid is
simply not available and photovoltaics are an obvious answer. There are
other
applications where photovoltaics can replace grid power without the
normal
complexities that are required in grid connected solar systems. For
example, a
small solar panel can power an attic fan. This fan would be designed to
work
exclusively from the panel and not the grid. This simple system would
not
ventilate the roof at night, but its main purpose would be to remove
heat
generated by the sun in daytime anyway. The result is a system that is
simple
and low in cost.
Another example is a solar powered pump for a pool or an irrigation
system. A
solar array connects directly to an electric pump that is designed for
direct connection.
Without the added complexity that a grid-connected array requires, or
the
requirements for versatility to provide power for a wide range of
appliances or
to work at night or in the rain, such a system can easily compete with
a
conventional grid supplied or gasoline powered pumping system.
Grid
Connected
Photovoltaics
Since a photovoltaic panel generates direct current and our
infrastructure is set up for alternating current, an electronic device
called an
inverter must be added to the system so our conventional appliances can
use the
power.
In order to use energy at night or on cloudy days, some form of storage is necessary. Where utility power is available,
the building can generate power into the grid and actually allow the
electric
meter to run backwards and earn a credit for the owner. When the sun
doesn’t
shine, the meter would then wind normally. The benefit to the owner is
reduced
electric costs and elimination of the need for expensive and bulky
storage batteries because the
grid acts as the storage system. The power company actually benefits as
well.
During the peak demand periods their generating capacity is being
supplemented
by their solar customers. Also the grid is less stressed by having
generation
spread
out along it instead of having all the generation concentrated at one
end.
Even still, grid connected systems are the most complex and
expensive of all solar systems. The challenge is to proportion them
in a way
where their payback can occur during their lifetimes.
No matter what
the costs,
all solar systems are environmentally beneficial. As technology
progresses,
costs will continue to drop until grid connected systems will be
more
economically
beneficial as well. Of course, regardless of any improvements
in the technology, there will most certainly be
increases in the costs of conventional power, which will make the
golden age of
solar energy arrive that much sooner.
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