July 2009
Q: I have 20 60-watt recessed lights in my house and am looking into LED bulbs to replace them. The LED supposedly uses 2.5 watts to put out the same light that the 60-watt bulbs do. Would it be worth replacing all 20 bulbs? How long before I recoup my investment? LEDs also supposedly last 100,000 hours compared to the 5,000 hours for the regular bulbs. Do you have any insight?
J. Russell, Morganton
A: Light-emitting diode lighting technology (LED) has certainly gained consumer interest in the past several years because it touts long life and energy savings. Both are true. Current and familiar applications for LED lighting technology that residential consumers may have seen are LED flashlights, lighting under counter kitchen cabinets, and other specialty lighting for commercial buildings such as exit signs and specialty lighting for the entertainment business, like Casino type signage. The key here is that LEDs are most currently cost effective and best suited for “specialty” or niche-type applications. However, they are extremely difficult to justify as a general incandescent lamp replacement in existing homes. Some day that will change as LED production and fixture technology ramp up and prices come down.
So, for homeowners with multiple types of lighting sockets in their homes, what are the best options for replacing incandescent bulbs and does LED have a part in this equation? Generally, the recommendation for your residential recessed can lights, as well as any other lights containing an incandescent lamp source in your home, is to replace them with an appropriate style CFL (compact fluorescent). CFLs are commercially available, have a long life and a relatively low cost. Because they require less energy to produce an equivalent amount of light (measured in lumens) per watt of electricity, they save energy and money.
LEDS are still hard to justify in terms of cost, unless perhaps they are “on” all the time or in a very hard-to-reach location where prolonging lamp life has value beyond energy savings. Example: A quality, 10-watt LED lamp costs over $40 (if you could find one), has a 20,000-hour rated life, and provides 320 lumens of light. By comparison, a quality CFL costs around $8, consumes 16 watts, produces 750 lumens of light and is rated for 10,000 hours (that’s almost seven years “on” if the light averages four hours per day, every day). So, in this example, the LED saves seven watts per fixture over the CFL. Over the seven-year life of the CFL, the LED energy savings would be 70 kilowatt-hours greater than the CFL, or $7.70 at 11 cents per kwh average. The LED would save you a little over $1 per year per lamp compared to the CFL.
So, it makes sense to consider installing CFLs now, then revisit the LED issue in seven years, when the technology and price likely will have changed.
Rick Schroeder, GreenCo Solutions
GreenCo Solutions, Inc. is a not-for-profit services company owned by North Carolina’s electric cooperatives to help its members meet their energy efficiency and renewable energy goals in a comprehensive, balanced and collaborative manner.
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