Hey Mr. Green,
Your comparison showing energy use of incandescent bulbs to fluorescent bulbs was interesting. So how do LED bulbs compare to fluorescents? —Jeff, in Southhampton, U.K.
Your question arrived the day after the U.S. Environmental Protection Agency issued its new Energy Star ratings for LED lights—a wonderful coincidence, if not necessarily inspired by the voice famed for declaring “Let there be light.”
Comparing the EPA’s Energy Star ratings for the two types of bulbs, you find fluorescents are somewhat more efficient LEDs, requiring about two-thirds as much energy for the same intensity of light. Fluorescents have a light output of 65 to 75 lumens per watt, compared to LEDs’ 45 to 55 lumens per watt. But of course LEDs are still way more efficient than incandescents, using only about a third as much energy for the same level of illumination.
An advantage for LEDs is their longer life span, most being rated for 25,000 hours of service, compared to 10,000 hours for most fluorescents, and the fact that they do not contain mercury. You can do your own comparisons of hundreds of lights by consulting the Energy Star ratings for fluorescent lamps and the Energy Star ratings of LED lamps. Note that these ratings are for Energy Star-qualified models, not types that fail to meet EPA standards.
Price remains a barrier for LEDs, as is often the case for a new technology before economies of scale can be achieved and research and development costs are defrayed. Remember when fluorescent lights cost far more than today?
The cost problem might be eased if you can find rebates available from power companies and manufacturers, or tax incentives from the government. For information, go to the U.S. Department of Energy’s Database of State Incentives for Renewables & Efficiency, or to the EPA’s Energy Star listings for incentives.
NOTE: These sources are worth consulting not just for lighting, but to find out about possible savings on alternative energy and numerous electrical appliances and devices designed to conserve energy.