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A sign of progress: LED bulbs hitting the stores

March 15th, 2009 · No Comments

Every day, I strive to Make Energy CENTS from the Home to the Globe. Whether programming the thermostat to low temperatures overnight to providing comments on national energy policy drafts to opening discussions as to Energy COOL technologies and concepts, my efforts to Energize America to a prosperous, climate friendly future cross a broad spectrum.

Thus, discussions on efforts within my own home, from the simple (leak sealing, efficient lighting) to the (often annoyingly) complex (solar hot water). Last discussion: heating with wood. Tonight’s discussion: transitioning to LED lighting.

Walking the aisles of that Box Warehouse Costco Friday brought a sign of progress. Costco has long carried CFLs but now has LED bulbs for sale at the type of prices that might get ‘average’ consumers to make the leap. On sale, both for slightly less than $14, three ‘replacement’ floodlights for 65 watts and ‘replacement’ accent bulbs for 40 watts. Okay, time for an experiment with those ‘accent bulbs’ as there is one fixture in the household with incandescent bulbs (three incandescents and two CFL accent bulbs).

(A quick note: these are not the first LEDs in the house. We’ve had LED recessed lights for years, but they were far from mass market choices. And, there are the LED string lights. And, there are LED flashlights, the LED reading lights, the almost never used LED night light, and the recently purchased LED clamp-on lamps for the kids.) But, this is the first time I’ve seen general illumination LED lights, truly competively priced, on a regular stores’ shelves.)

Now, some numbers: to replace 40 watt incandescent and 11 CFL, the LEDs rate in at 1.5 watts according to the packaging. A 1000-1500 incandescent life, 4000 CFL life, a 30,000 LED life. The cost to buy: three incandescent accent bulbs perhaps $2 ($0.66 each), CFLs perhaps $5 ($1.33 each), and the LEDs $14 ($4.66 each). So, quite clearly the “cost to buy” goes from low to medium to significantly higher. The real question, what is the “cost to own” differential?

Let’s run some numbers. 40 hours / week over 1 year and 5 years, in kilowatt hours, dollars, and carbon dioxide terms.

Kilowatt hours

Per Week Per Year 5 years
Incandescent 1.6 83.2 416

Compact Fluorescent .44 22.88 114.4

LED .06 3.12 15.6

No surprise here, at all, the incandescent burns far more electricity per year.

So, how does that translate into dollars and cents. Now, the US average is about 10 cents / kilowatt hour now, but we’ll use my 8.5 cents / kwh.

Electricity cost

Per Week Per Year 5 years

Incandescent $0.14 $7.07 $35.36

Compact Fluorescent $0.04 $1.94 $9.72

LED $0.01 $0.27 $1.33

And, that larger electricity use translates, ever so shocklingly, into a higher electricity bill. And even over one year, the electricity differential blows away the cost differential between the incadescent and more efficient lighting options.

And, there is another element of that “TOC” (total owership cost): the capital investment of replacing the bulb. Let’s be generous and assume a 2000 hour average incandescent life, an 8000 hour CFL, and perhaps a 20,000 hour LED life. Over five years, that means 5 incandescents ($3.30), 2 CFLs (actually, 1.25 but the capital cost is within the 5 years) ($2.66), and 1 LED ($4.66).

How does this translate?

Total ownership cost (capital cost plus electricity)

One Year Five Years
Incandescent $7.73 $38.65

Compact Fluorescent $3.27 $12.36

LED $4.93 $6.01

If you have trouble believing those “you will save $X” on the packaging, try to get past our cultural conditioning to question ALL-CAP ADVERTISING blaring at us. What is interesting, in fact, the numbers tend to look better than most CFL and LED packages suggest as they only count the electricity, without looking at the cost of all those additional light bulbs.

It’s not all about money, is it?

We won’t change the world by screwing in a light bulb but, one could argue, we won’t change it without doing so. Quite roughly, across the entire United States, the average kilowatt hour has a pound of CO2 emissions associated with it. (Coal electricity = 2+ pounds/CO2 per kwh; solar / wind / geothermal / hydro / nuclear are near 0.)

lbs CO2, US average of 1 lb / kWh

Per Week Per Year 5 years

Incandescent 1.6 83.2 416

Compact Fluorescent .44 22.88 114.4

LED .06 3.12 15.6

Now, let’s remember we’re talking “accent light” (candle), it is rare to see one of these alone. My particular fixture: 5 bulbs. Over a five year period, five incandescent bulbs used 40 hours/week would emit over a ton of CO2 while five of the LEDs won’t top 100 pounds. Now, this is a type of change that we all can live with.

(Note: As the last fixture in the house, this lamp has been very lightly use, with some general room CFL lighting preferred over having 140 watts (three incandescents, two CFLs) burning. This is now a 27 watt fixture (three LEDs, two CFLs).)

NOTE about comparing lights, An issue with the “Lights of America” LED bulbs and their packaging. Neither the packaging nor the bulbs provide any information on lumens. While these bulbs provide more than adequate light in my lamp, eyeball suggests considerably less light output than the 40 watt incandescent next to it. In fact, based on commonly understood luminous efficacy numbers, it is likely that the 40 watt incandescent is actually producing a minimum of three times as much total light output. Again, in my lighting situation this isn’t critical ,,, but it is concerning when a (large) light bulb package doesn’t give any indication of the actual light output in a standard measurement.

Pieces in the puzzle …

We are not going to solve the world’s problems by screwing in a lightbulb, through the choices in our home. We will not, however, solve problems without becoming Energy Smart (or less energy foolish) through out lives. Here is an example of trying to Make Energy CENTS from the Home to the Globe.

Tags: Energy · eco-friendly · electricity · emissions · energy efficiency