Thursday, February 26, 2015

The True Cost of Incandescent VS LED

Ever wondered if it is truly cheaper to go LED over Incandescent bulbs?
Lets do a little bit of everyone's favorite subject...
MATH.

The average Incandescent light bulb will usually last around 5000 hours on average (yes some last a bit longer and many last far less)..

So to get what one 60W light bulb costs we take 1000 watts and divide it by 60 to get how many hours it takes for this bulb to reach 1 KW/h.

1000/60 is 16.6 (so lets say 17 for argument's sake)
This means that it takes about 17 hours of burn time for 1 KW/h for a 60W light bulb.

So now we'll take 5000/17 to get the total amount of KW/hs for the life of this bulb..

That's 294 KW/hs...

Average cost is about $0.115 per KW/h..

That works out to be... $34.00 over the life of the bulb.

Now add about $1.00 for the cost of that bulb and you have $35.00 for the entire cost of the life of the bulb.  That 60W light bulb has now cost you $35.00 over the span of 5000 hours.

 I know what you're asking'

Aren't LED bulbs really expensive?

Well, initially they seem to be a little on the high side, I agree.  I mean, $10.00/bulb over the cost of $4.00 for a 4 pack of Incandescents..

Except that's not exactly true.  That $10.00 bulb will last 5x longer than the average Incandescent bulb.
Lets do the exact same math to find out what that bulb will cost over its life.

So we'll take 1000/10 = 100...
Already it's looking better.  This bulb takes 100 hours of burn time to burn through 1 KW/h..

Alright, and the average lifespan of these bulbs is around 25000 hours, which is 5 times the average lifespan of a typical Incandescent bulb.

Okay, so we take that 25000 hour life and divide it by 100.  That's 250 KW/hs over its lifespan.
Over that time at $0.115KW/h it'll cost about $29.00 to run that light.
I know what you're saying...

That's a total of $39.00 for the total cost of the bulb!!!!

Okay, sure, but lets look at it this way.. Divide that $39.00 by 5. Why?  Simple, the bulb lasted 5x longer than the incandescent.  So in 5000 hours the total cost of operating that bulb has now been about $8.00 including the cost of the bulb considering you are now having to shell out to replace that 60W light bulb that just burned out..

So take a look at that light fixture hanging over your dining room table with 5 or 6 60W light bulbs in it.  Yes, it looks lovely!  But imagine in 5000 hours that fixture has just cost you $170!

Change those to LED and in 5000 it'll cost you $40.00..
That's a saving of $130!  How many other light bulbs do you have in your house?

It's pretty incredible that a LED bulb can really save you that much money in the long run.  Don't forget that if you want to save money you might have to dole out a bit of cash from the start.

The basic rules for shopping for LED bulbs is this;

Highest amount of Lumens
Lowest amount of watts.

The higher the LUMEN count on the lower the wattage the better the saving in your pocket!
Lumens is the measurement of light.  The average 60W incandescent light bulb gives off approximately 800 Lumens.   So to make a direct replacement of a 60W incandescent for a LED bulb, find one that gives off between 750 and 900 lumens.  Also try to find a bulb that is no higher than 11W.  11W for a LED as a 60W incandescent replacement is a little high, considering you can easily find ones that are 8-10 watts giving out 800+ lumens.

The other key is colour temperature.  Measured in degrees Kelvin, a incandescent bulb is around 2700K.

2700K is a very very warm colour, in the yellow/orange light spectrum, but is the colour we all associate with... home..

3000K is a bit whiter, and similar to the colour of Halogen lamps.

4000K is a lot whiter and similar to offices and schools

5000K is classified as Natural Sunshine.  Light that is streaming in through a window is around 5000K and is a very beautiful colour when used in the right context.  However it is very white, and you will most likely not want this in a bedroom, dining room or living room.  They are good for a kitchen or a bathroom, but the colour can feel a bit harsh.

6500K is classified as DAYLIGHT.  If you are standing in the sun when it is at its zenith you are at 6500K colour temperature, which is into the blue-side of the colour spectrum.  I have not seen a single LED bulb at this colour for sale that wasn't a specialty bulb, but I thought I'd at least mention the colour.

So there you have it.  It may seem like you're dishing out a bit of money at the start for LEDs but for that money you put out initially, you are saving in the long run!

Yes my entire house (save for about 5 fixtures) is LED.  The 5 other fixtures are.. 1 Incandescent and 4 fluorescent 4' T8 tubes.  The fluorescent tubes will soon be replaced with LED tubes instead....

Until next time....

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