Replace Halogen Lamps With LEDs? You'd Be Mad Not To!
12:30 AM
If you were anticipating a typical "how to" piece, you know the type, long on bland verbiage and short on factual information that scarcely manages to argue the case suggested by the title, then you're in for a let down (or an unexpected surprise, depending on your viewpoint). I really can't be bothered and quite honestly I hardly need to write anything at all - the numbers say it all, so let's get stuck in.
The average mains powered GU10 halogen down light (as very commonly seen fitted into ceilings) can be bought for around 2, uses 50 watts of electrical power and has a lifespan of about 2,000 hours over which time it will have cost 12 in electricity to operate. This is based on the average price of 0.12 per kWh and having the light on for a mere 3 hours a day (which works out at close to 1,000 hours over the course of a year).
An equivalent GU10 format LED (in other words a quality LED such as Sharp's Zenigata that is functionally almost identical) requires just 4W and will run for 40,000 hours or more; the purchase price is at the moment 24 but over 2,000 hours it costs just 0.96 in electricity to run.
Looks like the LED has priced itself out due to the much higher purchase cost, doesn't it? But let's add a bit more "real world" perspective into this picture.
To begin with, to compete against the lifespan of a single LED requires replacing the halogen 20 times, which brings the true purchase price up to 40 (20 x 2) which is nearly double the LED's 24 price tag.
Additionally, if instead of comparing the two over the rather unimpressive lifespan of the halogen we use that of the LED (40,000 hours) then the LED costs 19.20 to run whereas the halogen lamp is a whopping 240.
As a final step, let's now add together the running costs over 40,000 hours with the "real" purchase prices, and immediately it's clear that the total bill for the LED will be 43.20 as compared to 280 for the halogen lamp (and its many replacements). If you thought this would be an exercise in scraping out 10% or even 50% savings, think again - the numbers do not deceive, halogen lamps cost 1000% more than LED equivalents.
Even with the initial investment figures added back in, halogen lighting is easily 700% more expensive. Interestingly also, in this example the LED actually costs less to run than to buy. The halogen lamp is superficially cheap to buy (but as we saw ends up costing nearly twice as much as the LED due to constant replacement costs) yet hugely expensive to run. It's a totally different ball game.
Of course, this is a very scaled down example applied to one little-used light bulb. I have just walked from my North facing kitchen where 10 down lights are almost permanently on from 7:00 A.M. to midnight, thru a hall with little natural light and 4 more halogen lamps, into my office where a further 6 glow maybe 6 hours a day.
Totting this lot up we can see that even these 3 rooms use more than 100,000 hours worth of electricity each year (that's ((6*6hrs)+(10*17hrs)+(4*17hrs))*365 days = 100,010 hours) which works out at (100,000 * 50W * (0.12/1000)) 600 just in electricity costs for halogen lighting, compared to a rather more reasonable 48 for LED lighting.
Take a few more practical examples - offices, shops, hotels, hospitals, airports, the list goes on - where artificial lighting is on almost constantly; throw in some currency symbols and suddenly mathematics mutates into economics and we're looking at eye-watering sums of money.
We have already established that the purchase cost difference between the two gets cancelled out about halfway through the lifespan of the LEDs and that over time it's actually much cheaper to buy 1 LED rather than replace a halogen lamp 20 times. We also now know that halogen lamps cost 12 times as much to run as equivalent LEDs. So why then would anyone choose NOT to switch to LED?
The average mains powered GU10 halogen down light (as very commonly seen fitted into ceilings) can be bought for around 2, uses 50 watts of electrical power and has a lifespan of about 2,000 hours over which time it will have cost 12 in electricity to operate. This is based on the average price of 0.12 per kWh and having the light on for a mere 3 hours a day (which works out at close to 1,000 hours over the course of a year).
An equivalent GU10 format LED (in other words a quality LED such as Sharp's Zenigata that is functionally almost identical) requires just 4W and will run for 40,000 hours or more; the purchase price is at the moment 24 but over 2,000 hours it costs just 0.96 in electricity to run.
Looks like the LED has priced itself out due to the much higher purchase cost, doesn't it? But let's add a bit more "real world" perspective into this picture.
To begin with, to compete against the lifespan of a single LED requires replacing the halogen 20 times, which brings the true purchase price up to 40 (20 x 2) which is nearly double the LED's 24 price tag.
Additionally, if instead of comparing the two over the rather unimpressive lifespan of the halogen we use that of the LED (40,000 hours) then the LED costs 19.20 to run whereas the halogen lamp is a whopping 240.
As a final step, let's now add together the running costs over 40,000 hours with the "real" purchase prices, and immediately it's clear that the total bill for the LED will be 43.20 as compared to 280 for the halogen lamp (and its many replacements). If you thought this would be an exercise in scraping out 10% or even 50% savings, think again - the numbers do not deceive, halogen lamps cost 1000% more than LED equivalents.
Even with the initial investment figures added back in, halogen lighting is easily 700% more expensive. Interestingly also, in this example the LED actually costs less to run than to buy. The halogen lamp is superficially cheap to buy (but as we saw ends up costing nearly twice as much as the LED due to constant replacement costs) yet hugely expensive to run. It's a totally different ball game.
Of course, this is a very scaled down example applied to one little-used light bulb. I have just walked from my North facing kitchen where 10 down lights are almost permanently on from 7:00 A.M. to midnight, thru a hall with little natural light and 4 more halogen lamps, into my office where a further 6 glow maybe 6 hours a day.
Totting this lot up we can see that even these 3 rooms use more than 100,000 hours worth of electricity each year (that's ((6*6hrs)+(10*17hrs)+(4*17hrs))*365 days = 100,010 hours) which works out at (100,000 * 50W * (0.12/1000)) 600 just in electricity costs for halogen lighting, compared to a rather more reasonable 48 for LED lighting.
Take a few more practical examples - offices, shops, hotels, hospitals, airports, the list goes on - where artificial lighting is on almost constantly; throw in some currency symbols and suddenly mathematics mutates into economics and we're looking at eye-watering sums of money.
We have already established that the purchase cost difference between the two gets cancelled out about halfway through the lifespan of the LEDs and that over time it's actually much cheaper to buy 1 LED rather than replace a halogen lamp 20 times. We also now know that halogen lamps cost 12 times as much to run as equivalent LEDs. So why then would anyone choose NOT to switch to LED?
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To find out more about this subject, check out this hot recommendation from Louisa Kennicot that examines the topic of 12v LED lighting.
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