LED lights: a Bright Idea?



The Economics of LED Bulbs

About 3 years ago we installed 4 sets of track lighting which involved 3 halogen bulbs each.  The two that we use the most, in the kitchen, I have long been aware of not only the frequency of changing the bulbs, but how quickly they get hot. Both conditions add up to a lot of cost: buying new bulbs and the heat generated indicates a lot of energy being used. So when I was in Costco last week, I noticed that they were selling the same bulb in LED and decided to buy one to see if it shone sufficient light and then I would look at the economics of LED. At the same time, Costco had a pack of three bulb-style LEDs and I bought one of those too.

The light performance fine. The lights give off a different hue than the halogens and CFLs that they replaced, but the brightness was sufficient and that is what I was mainly after.

The question remains, does it finally make economic sense to start making the switch to LED’s now that LED lights are coming down noticeably in price? A year ago, LEDs were still pretty price-prohibitive so I never looked at them seriously except in a couple of applications that have worked out very well over the last few years (more on that later).

So, the analysis.

The halogen/LED comparison

Halogen                          LED

Cost of bulb                                         $2                                 $7

Watts                                                    50                                   8

Cost of electricity/year

@6 hours/day@.11/KWH                 $14.41                             $2.09

Savings 1 bulb                                                  $12/yr

Savings 12 bulbs                                             $144/yr

Payback time                                                6 months

Life of bulb                                   3 years                             15 years

This one is a no-brainer. Not only is the extra cost of the LED bulb paid off in 6 months, but in the long run, you will spend more on the replacement halogen bulbs than on the LED. However, these happen to be high usage/high wattage lights so the next analysis will be on the 800 lumen (60 watt incandescent equivalent) bulb-style lights.

800 Lumen bulbs (similar to a 60 watt incandescent bulb)

CFL curly     CFL Bulb        LED Bulb-style

Cost of bulb                               $1.50            $5.00                $6.50

Number of watts                         23                 23                       9.5

Savings of electricity/year

@6 hours/day                                                            $4.80

Payback                                  16 months        6 months

@2 hours/day                                                             $1.60

Payback                                 49 months      19 months

This one gets a little more complicated. If you are using bulb-style CFLs, it is definitely worthwhile switching to LEDs. However, as a general rule, if you are using the cheaper curly style CFL bulbs and very few hours, it still makes sense to stick with the curly CFLs unless it is a high usage light.

If you have lights that stay on 24/7, run to your store right now and get an LED replacement!

Where I have used LEDs for some time now is a big flood light outside my rear door. It replaces a 150W incandescent and is a big savings. The other one is an outdoor solar floodlight. Its low wattage doesn’t draw as much on the battery so it works well in our low light northern winters. My old halogen solar powered light did not perform well after a couple of cloudy winter days.

So if you don’t want to do the math on this, here are some general economic rules (depending on bulb and electricity price in your area):

1.Replace all high usage lights with LED.

2.Replace all incandescent lights and halogen lights with LED.

3.Replace most bulb-style CFLs unless they are almost never used.

4.Don’t replace low usage curly style CFLs….yet.  This might start to look better in the next year or two.


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