Take the example
of a $0.99 standard 100 Watt light bulb
that is operational 24 hours per day, 7 days per week. This fixture
will use 870 kW/h over a year, at $0.7 per kW hour, it will cost
you a little over $61.00 for the year, with a gross cost
including purchase of $62.00
Compare this to a 28
Watt compact fluorescent light bulb, which costs $21.00
to purchase. This fixture replaces the old 100 Watt fixture, and
provides the same light intensity. It will consume 244 kW/h per
year and cost you $16.50 in electricity costs for the year, with
a gross cost of $37.50 for the year
So, which is the most
expensive bulb at the end of the year? The compact fluorescent is
a clear winner. Factor in that the compact fluorescent fixture will
outlast a conventional bulb by upwards of 10x, it continues to pay
for itself long after the "cheap" bulb has burned out
a few times.
Lights used more often have the opportunity to save the most energy.
Put the most efficient lights in main rooms, desk lights, the kitchen
and the dining room. Don't forget about the outdoor lights - even
better, install motion sensors or timers on outdoor lighting. Task
specific lighting is a more efficient way of using lights. By illuminating
a specific area rather than the whole room a much smaller light
may be used.
Most lighting fixtures that utilize standard incandescent fixtures
can easily accommodate a compact fluorescent fixture. Installation
is generally as simple as unscrewing your old bulb and replacing
it with a new compact fluorescent. If your fixture has a shade or
diffuser, you can use the less expensive fixtures that do not have
a globe. However, if the bulb is visible such as outdoor lighting,
recessed ceiling fixtures or track lighting you will see better
results with the capsule-style fixture. Applications that require
directional lighting can use the optional reflector that fits over
top of the globe style fixtures.
The ability to have bright, reliable light at any time is often
the largest benefit of an alternative energy system. There is no
longer any reason to have to tolerate candles or smelly, dangerous
and expensive kerosene fixtures. Propane lighting may seem like
a good option, but after a few days of their loud noises and glaring
light, silent battery powered lights seem like a dream come true!
In many renewable energy systems lighting is the first or second
largest entry in the energy budget. Replacing standard incandescent
lights with compact fluorescent fixtures (CFLs) can reduce the energy
consumed by as much as 75% with no reduction in light quality.
DC or AC Lighting
If your building is already wired for AC electricity, it is
often the simplest to install an inverter and use efficient AC lighting.
A word of caution, large inverters are not as efficient when running
tiny loads, such as a few lights. It may be beneficial to have a
small inverter dedicated to your lighting loads. DC lighting is
more efficient and does not require the use of an inverter. The
fixtures in general are more expensive than the AC ones, because
of the economies of scale. Automotive taillight bulbs, commonly
used in boats and RV's are incredibly inefficient as are standard
12V incandescent bulbs which are found in marine stores. Be wary
of the low initial price tag The additional solar panels required
to operate these heaters that are used as a light bulb will make
the higher up front costs of the efficient lights seem more reasonable.