#

Green Collar Careers - Lighting

Low cost incandescent bulbs were a revolutionary product that over 100 years later hasn’t changed much. Nearly 90% of the energy required to light an incandescent bulb is turned into heat rather then light so they will add significantly to the load on the air conditioner during the summer season. Heat generated from an incandescent costs more then twice as much as the heat from a heat pump so its not a very cost effective heater. The only positive point about an incandescent bulb is they are the least expensive to purchase.

Halogen lighting is slightly more efficient then an incandescent by about 15%. From practical experience they have about the same life as an incandescent.

Compact Florescent Lights (CFL) require ¼ the power for the same amount of light from an incandescent. Not all standard fixtures can accept a CFL although generally at least 80% of the fixtures in a typical home can. CFL’s do not work as well in colder climates so they may not be very good for outdoor lighting. CFL’s generally cost about 4 times that of an incandescent which is probably the main reason most people still use incandescent lights. Most CFL manufacturers may claim 10 times the life over an incandescent, but that’s only in specific laboratory conditions designed to optimize the life of the CFL. In practical application, 4-5 times the life is more realistic making the CFL cost effective based on replacement cost alone.  The one drawback to CFL's is they don't work very well on dimmer circuits.  When installed on a dimmer equipped circuit they may take a few seconds to "fire up" even with the switch turned up all the way.

Standard Florescent Tube (SFT) fixtures are still the most cost effective of the lighting methods however they require special fixtures and lack the aesthetic appeal for most homeowners. That’s why they are mostly only used in garages and utility rooms. SFT’s also are prone to a flicker that some people find annoying. This flicker has been resolved with CFL and some of the higher priced SFT’s.

Light Emitting Diode (LED) technology will be the next generation of lighting but isn’t yet ready for cost effective use. LED’s are about 95% efficient, with nearly all the losses in the voltage conversion circuits that are self contained. The LED’s themselves will last 20+ years, however the voltage conversion circuits will only have a life of about 10 years at this point. More of a novelty then practical, its expected that cost effective versions will be available within 5 years.

Understanding the different lighting options it should be clear that the CFL offers the best solution at this time. If the homeowner is using exclusively incandescent lighting, the following gives a typical savings potential in a moderate climate by switching to CFL.

Energy reduction for CFL vrs Incandescent:

70% reduction for lighting energy + 10% reduction for heating energy = 80%
Applied to 80% of the home light fixtures; 80% * 80% = 64%

Average portion of power consumed for lighting from Chart 202 = 8.8%
Reduction of power consumed for lighting; 8.8 * .64 = 5.6%
 

CFL lighting also provides a sales and installation opportunity for the Home Energy Auditor.  Keeping a range of bulbs in your inventory and a ladder for installing them can be profitable.

LED's seem to offer an appealing attraction to the gadget-conscious.  It would be worthwhile to have a few LED spotlight bulbs.  LED's "shine" in fixtures that are high up and shine down as these are the most difficult bulbs to replace and the ultra long life of an LED will last for up to 20 years.