Other things to consider are color temperature and getting the light
where you want it. In my home office and in one of my bathrooms, I
installed track lighting and use low voltage MR16 halogen reflector
light bulbs (code BAB). In each room I replaced three 75-watt regular
incandescent bulbs (225 watts total) with six 20-watt BAB bulbs (120
watts total). Not only do I have light where I want it at lower power
consumption, I believe the overall light level seems brighter. The
color temperature of the halogen bulbs is very nice and the overall
ambience of the two rooms is very pleasing.
In my opinion, and in terms of the overall lighting effect, compact
fluorescent bulbs don't hold a candle to low-voltage halogen bulbs.
(Sorry; couldn't resist the wording.) The lighting from the reflector
halogens is so pleasant I would be inclined to keep them even if they
turned out more expensive and/or less efficient. I tried compact
fluorescent lights in my daughter's room and she made me take them out.
I know my savings in each room is not as great as the difference between
225 watts and 120 watts because there is some inefficiency in the
voltage reduction circuitry. I do not know how much waste there is, but
I know the electronic components run fairly cool. I also am aware that
electronic voltage reduction is not friendly in terms of keeping a nice
sinusoidal waveform on the AC wiring in my home. Some people worry
about interference with TV and radio, but I do not notice any of this in
my home.
At a place like Lowes or Home Depot I can get MR16 BAB bulbs for about
$4.00 on sale ($5.00 regular price) and 75-watt incandescent bulbs for
$0.25 each. Regular bulbs last 750 hours and halogen bulbs last 3000
hours. I have had my lighting in place for about 6 years and have
replaced only two bulbs in the bathroom and only four bulbs in the
office over this time period. That would be consistent with running the
bathroom lights about an hour a day and the office lights about 2 or 3
hours a day. Therefore the lifetime rating on the MR16 bulbs is
reasonably accurate.
My electricity is fairly inexpensive (about $0.07/kW.hr). If I use
about 100 watts less power in a room that has six 20-watt BAB bulbs
rather than three 75-watt regular bulbs, then in 3000 hours I save about
300 kW.hrs or about $21.00, but I use about 6 BAB bulbs (about $24.00)
rather then about 12 regular bulbs (about $3.00). Therefore the cost is
a wash depending on the price I pay for BAB bulbs and the cost of
electricity. The quality of the light is what makes it worth it.
Michael D. Edmiston, Ph.D.
Professor of Chemistry and Physics
Bluffton College
Bluffton, OH 45817
(419)-358-3270
edmiston@bluffton.edu