Deck the Halls with LEDs

As a parent of two preschoolers, I get talked in to many things.  This past weekend, I was talked in to decorating our front porch with a string of holiday lights.

For the pre-tax price of $16.99 at Costco, my husband brought home a 33-foot string of 100 multi-colored miniature holiday lights for me to indulge my two little chickadees’ wishes.

$16.99?!?  Has there been that much inflation in holiday light prices since last season when I purchased what I thought was a virtually identical set for $8.99?

Reading the not-so-fine print on the box, I discovered $16.99 buys you a string of LED holiday lights. My virtually identical string was a string of standard incandescent holiday lights.

Having just replaced all of our recessed ceiling light fixtures with LED retrofits, here is my lay-person’s description of the difference between standard incandescent lights and LED lights.  While LED lights and standard incandescent lights both create light, the way in which they do it is substantially different.  Standard incandescent light fixtures create light by passing electricity through a metal filament until it becomes so hot that it glows.  LEDs, or light-emitting diodes, on the other hand, create light from the movement of electrons through a semiconductor material.

These technological differences create some substantial differences in other features of the light fixture that consumers surely care about.  For example, incandescent lights generate heat and have a relatively short lifespan because the metal filament burns out.  LED lights, on the other hand, generate virtually no heat and have a substantially longer lifespan than incandescent lights.   LED lights also use less electricity than standard incandescent lights, which means lower electricity costs to run LED lights compared to incandescent lights.  And my personal experience with our new recessed ceiling lights is that LED lights provide a much nicer looking light than standard incandescent ceiling lights.

Is there a downside to LED lights?  The biggest drawback of LEDs is the sticker shock:  The upfront cost of an LED is substantially more than an incandescent.

I’ll be completely honest:  It was easy for me to justify the $16.99 based simply on the warm-glow I received from fulfilling my kids’ wishes.

But as we hung-up the lights together last night, I considered the table of “Energy Savings Comparison” that the LED holiday light manufacturer provided on the box, presumably put there to help consumers overcome the sticker shock.

In the table that I replicate below, I use my expected seasonal use (8 hours a day for 35 days) and I replace the U.S. average cost of electricity shown on the box with the marginal cost of electricity that I pay to PG&E:

My one-season electricity savings amounts to roughly $2.72, far less than the $8 more in upfront costs from the LED lights.  But taking an NPV approach with a 1% discount rate, in just three holiday seasons, the annual electricity cost savings start to swamp the higher upfront costs.

One last calculation before I go back to basking in the warm glow of our holiday lights:  The manufacturer states that the average lifespan of the LED holiday light string is 20,000 hours.  By that account, I should get around 71 holiday seasons out of my new string of LED lights!

EMB

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7 Responses to Deck the Halls with LEDs

  1. Jardinero1 says:

    I understand lifecycle costs accounting. After figuring the lifecycle costs of Compact Fluorescents, I enthusiastically replaced all of my incandescents with Compact Fluorescents. The problem I have run into is that the Compact Fluorescents do not last anywhere near as long as the manufacturer claims on the package. In practice they last roughly twice as long as incandescents if you do not turn them on and off too much. If you turn them on and off with a high degree of frequency, like a closet light, they last the same number of hours as an incandescant. After that, I am very skeptical of the claims about lifecycle costs of LED fixtures.

  2. J.M. Dickenson says:

    My experience has been that the light quality from LEDs differs greatly from that of incandescent bulbs–the light from the LEDs creates a haze. That is fine for outdoor lights but very unpleasant for indoor, to me at least. It may be there are other types of LEDs or other brands that do not have this quality; however, the price of each LED bulb makes me hesitant to experiment. Seems manufacturers would have more of an incentive to educate consumers, assuming there are a variety of LED products with a variety of light qualities.

  3. David Jacobowitz says:

    Jardinero1, I agree with you about CFLs. Their actual performance has been much worse than what was promised and in many cases, the lifetime energy savings will not be realized. From engineering perspective, I think it’ll work out a bit better for holiday lights. For one, they are typically turned on only once a day.

    Another difference: A CFL has an electronic ballast. I think this is a significant source of failure for such bulbs. Most LED light strings have little or no power electronics to fail. (I’ve taken my fair share apart. Some have full fledged power supplies, some have simple diode rectifiers with a resistor to manage current, some have a capacitor to filter the DC, and some have nothing, relying on the LEDs themselves to provide the rectification and appropriate voltage drop. Most of these last ones have a characteristic flickery “electronic” look that I do not think conveys holiday cheer and warmth, btw.)

    Anyway, reduced complexity, I suspect, will make light strings even more reliable than the LED bulbs intended for normal light fixtures, as the latter do have relatively sophisticated power electronics in them. (I just bought four new LED recessed cans for $40 each. They are projected to last 20 years, but I’ll eat my hat if they all last that long.)

    Also, for both incandescent and LED, when a bulb fails, the string is still usable — almost guaranteeing you’ll get many years of useful service from either type — if you can tolerate a few dark bulbs.

    I have a quibble with the economic analysis above, though. I am seeing incandescent strings for $4, not $9: http://www.osh.com/search?q=holiday+lights&restrictBy=price%3D%5B3%2C4)&viewas=grid

    That pushed back payback time a couple more years.

  4. Marc R says:

    Wow, at $0.29561/kWh candles look like an interesting alternative to anything plugged in.

  5. Benjamin says:

    Great post. I liked it very much. Thanks for sharing.

  6. Nice Blog with useful content. Thanks for sharing

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