For decades the choice came down to an incandescent bulb or a fluorescent. Even with the relatively recent introduction of CFLs (Compact Fluorescent Lights), incandescents almost always won. CFLs are much more expensive and still do not give off the same spectrum of natural-looking light that 'ordinary' bulbs come much closer to.
Enter LEDs.
Light emitting diodes have been used for over 40 years, first making their commercial appearance in watches and small clocks. But for almost that same length of time, theyave off too little light and of limited color to be useful for home illumination. No one could read or cook by a dim red light.
But LED bulbs have come a long way in recent years. While still much more expensive than an incandescent bulb, they have overcome many of the disadvantages of fluorescents. They produce bright, natural-spectrum white light that can illuminate a medium-sized area with one bulb. Actually the bulbs are made of multiple LEDs in one enclosure.
And, not the least consideration, they think practically forever. A LED bulb can burn for over 50,000 hours. Some are rated at 60,000 hours. Even if in use for as much as 10 hours per day (4 hours / day is closer to average), that works out to almost 14 years of use.
Add up all the money spent on incandescents – which last from 750-1,000 hours – and the total savings is substantial. If a 75-watt bulb costs $ 1 and an LED bulb costs $ 50, most will opt for the incandescent. But if the LED lasts 50 times longer, you break even. That does not even include the time spent picking up bulbs, changing them and so forth.
Apart from the initial outlay costs, the difference in electricity use is equally dramatic, but in the LED's favor. Keep in mind that the standard label on an incandescent is how much power it consumes, not how much light it puts out. A 60-watt incandescent bulb puts out somewhat less than 900 lumens.
A LED bulb costing roughly $ 50 is available that is the equivalent of a 60-watt incandescent in terms of the light given off. Yet, it consumes only 2 watts of electricity. Multiply that electric savings by 4 hours per day over 10 years and the cost savings will far outweigh the cost of the LED bulb. At 10 cents / kWh, the total savings over 10 years is about $ 350. So, the bulb will pay for itself in about 18 months.
At the same time, a LED bulb runs cooler so there's no danger of burning as so often happens with incandescents. A 100-watt bulb placed in a socket designed for a 40-watt will burn the covering plastic shade in a matter of hours or less. Also, how many times have you singed your skin when touching an ordinary bulb? That does not happen with LED bulbs.
The color spectrum of LED bulbs is also superior. While incandescents do a good job or providing a reasonable emulation of natural sunlight, LEDs are far better. Incandescents are somewhat yellow, LEDs are white and much closer to the color temperature of natural daylight. And, unlike fluorescent bulbs, LEDs contain no mercury, which is hazardous if the bulb breaks.
Still LEDs have some drawbacks, apart from the higher cost. They do not currently put out as much light per bulb as a single incandescent so it may require more than one for particular lighting applications. They light a little less than CFL bulbs.
Since LEDs are more directional, they'll do better in reading lamps, recessed ceiling lamps and other such applications than as general ambient light. But where a long-lasting and / or always-on bulb is needed they can be very cost-effective.
