Lighting 101 – An LED Primer

LED’s  . . . As Efficient As It Gets

by Steve Augustus of LED Dynamics

To the layperson, the new models of lighting can seem intimidating and expensive. What’s wrong with the lights we have now? We know they work and we like the light and they are cheap. We’ve tried compact florescent lights, or CFLs. The inexpensive ones are slow to warm up and offer a pale comparison to the light quality of the Edison bulb.

But if you are reading this newspaper, you know things are happening in the energy world. I’m here to tell you the revolution in lighting is now. The winner is an upstart in lighting called LEDs.

LED, or Light Emitting Diode, is the next evolution in efficient lighting. We’ve long used LEDs as indicator lights in equipment panels and home electronics, but a recent breakthrough allowed those solid little indicators to evolve into bright, white light for illumination. Since then, innovative companies have been producing fixtures and bulbs. And now the LED industry has managed a replacement for every kind of lighting.

First, look at energy efficiency. Edison’s incandescent light bulbs make light by heating a metal wire in a vacuum until it glows white and bright. An average Edison bulb uses 60 watts of power, 95% of this power goes to heat, 5% to light. By comparison, a CFL uses about 13 watts to electrically excite gas in a tube to make the same amount of light. With a ratio of 90% to heat, 10% to light, it’s somewhat better. An LED turns all that upside down. Using only 8 watts, it activates layers of incredibly thin chemical substrates to make light with a whopping 90% to light, 10% as heat.

Simply looking at efficiency, it’s an easy choice for LEDs. But the sticker shock makes pause. Compared to $1 or $5 for an incandescent or a CFL, an LED bulb of similar light output is around $35. Ouch…But look at a few more things before turning away. First, Vermont has good rebate programs that pay back an investment in LEDs. Check with your local lighting supplier. Second, LED bulbs last about 50,000 hours. Compare that with 10,000 hours for CFLs and 1,200 hours for incandescents. And third, the portion of your electric bill keeping the lights on will shrink to barely noticeable. It’s amazing! If you take the long view, all your expense for the bulb comes up front with one bulb compared with continuous maintenance and expense for replacement and making mostly heat with the others.

But, by far, what excites me most about LED lighting is that its uber-efficiency, in effect, changes the formula for renewable energy production. If we consume far less due to lighting alone, our wind and solar generation systems can be smaller and generate less.

LED Dynamics:  www.leddynamics.com