Why a more expensive LED actually costs less than a regular bulb
There is no question that the purchase price of LED lamps is significantly higher than that of either CFL (Compact Fluorescent Lamp) or conventional Tungsten or GSL (General Service Lamp) counterparts.
But the purchase price is not the full story. The cost of anything, light bulbs included, is what it costs to both buy AND use. What is known as Total Cost of Ownership.
A regular incandescent 60w GSL light bulb lasts about 1,000 hours and costs roughly £1.
An equivalent 7w LED light bulb lasts 50,000 hours and costs say £25 (in reality, rather less than that these days and getting cheaper all the time). Alternatively you might compare a standard 50W halogen lamp with a 6W LED spotlight – notice that in either case the LED uses nearly 1/10th as much power.
Doing the math
The accepted standard rate of electricity is 10 pence per kilowatt hour and our comparison will be over the lifetime of our LED lamp.
The GSL rated at 60w thus costs you £375 worth of electricity over 50,000 hours and has to be replaced 50 times, giving a total cost of ownership of £425.
An LED rated at 7w costs £44 over the same period and does not have to be replaced at all, giving a total cost of ownership (purchase + running costs) of £69.
The LED actually costs little more to run throughout its entire life than it costs to buy! This is simply unheard of in a light bulb – before now. And with purchase prices for LEDs dropping fast (as always occurs with any new technology as it becomes commonplace) the LED holds out a promise of extraordinarily low cost lighting.
The bottom line is that the “cheap” bulb is in real money terms £356 more expensive for you to own! And that’s just ONE BULB!
Assuming just 4 hours use per day, the payback time (the point at which you will have recovered all the initial cost difference between the two options) is about 2 years and it will actually save you a considerable amount of money for the next couple of decades after that.
This estimate is also being extremely generous to the incandescent lamp, since it has not accounted for increases in the price of either electricity or replacement bulbs, nor has it allowed for the fact that home LED lighting is in fact getting cheaper by the day.
LED Savings Calculators
If you want to play around with the figures yourself you can try the Cree Savings Calculator.
Or there is the rather simpler to use EXERGI Savings Calculator from UK manufacturer EXERGI whose products are in fact based on Cree LED dies.
For one with an interesting eco twist (it calculates environmental impacts as well as financial costs) then there is the Ledzworld LED Savings Calculator. This one even makes adjustments based on your own locality.
Ledon, maker of arguably one of the best regular bulb shaped LED light bulbs provides their own take on the matter with the imaginatively named Ledon LED savings calculator.
And here’s yet another savings calculator from Green Energy Efficient Homes.
These guys are Scottish LED specialists and their LED savings calculator is aimed particularly at comparing LED with halogen downlights (their target market is hotels, restaurants, retailers, cafés and gyms – big users of this form of lighting).
Not to be outdone, below is KuleKat’s very own energy saving calculator that simply requires you to provide the total before and after wattages (you’ll have to add them up yourself), approximate average daily use and the price you pay for electricity. This just provides a functional estimate of savings in terms of your electricity bill.
It has to be said with respect to all these various calculators that none of them agree with each other, and some are very specific to their own products (rather than general LED performance – if there even is such a thing). However, they do all paint essentially the same picture, which is that LED lighting saves money; how much exactly depends on your own usage, but seen simply as a percentage of current lighting costs it is uniformly fairly jaw dropping.
The other common thread is that the savings are magnified by:
- increases in the price of electricity;
- the number of lights you have;
- the amount of daily use.
An example…
For a fairly standard family household layout that uses banks of halogen down lighters (mixed mains and low voltage) in the kitchen, bathrooms, hallways and bedrooms (say 40-50 individual lamps in total) replacing these with LED lighting would save well in the order of £500 per year (and over the useful lifespan of the LEDs the savings could easily top £20,000).
Interestingly, the net saving is relatively unaffected by the amount of daily use for lighting. If you have your lighting on less (say 4 hours per day) then the payback period is longer, but so also is the total period of saving. If you increase to say 12 hours a day then the payback will tend be little more than one year but the savings are spread over a much shorter period which actually increases your annual savings.
So £14,000 over 11+ years of high use obviously puts £1,270 back into your pocket each year whereas over 35 years (the lifetime of an LED used 4 hours per day) the total saving remains about the same but each annual saving is only about £400.
Of course, this is only looking at replacing halogen spot lights throughout your home. There are many other areas where home LED lighting can be used to either replace or augment your existing lighting, but LED spotlights are a great way to quickly try out say some new bathroom or kitchen lighting ideas without great expense or disruption.
