The Low Down on Low Energy Low Cost Lighting
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So you’ve discovered LED light bulbs and want to get on board with this new ultra low energy technology, partly in order to adopt a slightly more green lifestyle, but not least because of the amount of money you can save.
Oh yes, don’t for a minute believe the widespread but entirely pernicious myth that environmentally friendly “alternative” products and processes cost more than their “conventional” counterparts. Certainly in the case of LED lighting, only a fool would defend (and continue to waste their money on) traditional incandescent light bulbs.
LED lamps consume roughly ten times less power than incandescent equivalents and easily last upwards of twenty times longer. Even though they cost quite a bit more to purchase, savings of this magnitude mean that most folk should recoup the purchase cost within a year or two at most (the more lighting you use the faster the payback).
Even compared to the more established low energy solution, namely compact fluorescent lamps (CFL’s), LED’s outperform them by a factor of about four in terms of energy savings. They also don’t come with the same baggage attached, such as slow startup times, poor color rendition and toxic ingredients such as mercury vapor.
But where to start? Well one area that LED’s have long excelled at is spot lighting – traditionally the preserve of the halogen lamp. It’s rare these days to find a public space, workplace or home even that does not have banks of halogen down lights recessed into the ceiling or set onto lighting tracks.
There’s a good reason for the ubiquity of this particular form of lighting, and that is because it is very effective at filling a space with good quality ambient light. Ironic for a product termed a “spot” light, but there you go…
But halogen lamps, as everyone knows, run extremely hot which gives another big clue to why you should replace this type of lighting first with LED equivalents. Heat almost always indicates wasted energy; in fact, engineers of all types devote endless hours to hunting down and eliminating heat loss precisely because it is so detrimental to efficiency.
About ninety percent of the electricity used to power a 50 watt halogen lamp ends up dissipated as waste heat. If you look up and can count say twenty halogen spot lights in the ceiling then that equates to one kilowatt of power required to light that room. That’s the kind of power necessary to run one of those electric bar room heaters.
LED lamps however don’t rely on heating a strip of metal so hot that it actually starts to glow (and thereby give off some light). Without getting into the physics of semiconductors, they essentially convert electricity directly into photons (light particles).
Because there is very little heat loss the result is that they can create as much light as a 50 watt halogen lamp but using only 5 watts of energy. In other words, they actually cost ten times less to run. For a building with say 100 halogen lamps installed, the financial implications are startling.
Assuming daily use of 5 hours and using the average price of electricity at 13 cents per kilowatt hour this works out at:
100 * 50 watt halogen = 5 kilowatts * 5 hours * 0.13 * 365 = $1,186 100 * 5 watt LED = 0.5 kilowatts * 5 hours * 0.13 * 365 = $117
An annual saving of $1,069 – not bad for just replacing a load of light bulbs?
Clearly, your own mileage is going to vary. But put aside for a moment your own personal gains from switching to LED. Can you even begin to imagine the sheer scale of the impact once most people on this planet go down this route? Makes you realize how much money and scarce natural resources has been going up in smoke all these years, just so we can see at night.
For a more detailed look at getting on board with LED lighting check out http://www.kulekat.com/led-home-lighting/led-home-lighting-a-buyers-guide.html
