Good Question: How Do LED Holiday Lights Compare With Incandescents?

SAN FRANCISCO (CBS 5) – If you’re putting up lights this holiday season, the wrong bulbs may lead to unwelcome present from PG&E. In this Good Question: How do the new LED holiday lights compare with the old incandescent type?

Our video report has more.

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  • Mike Locke

    How do you come up with $70/season to power a 123watt string of lights?

    At roughly the state average of $0.10 cents/kwh and lights on 24hours a day (not recommended) for 30 days (unusually long) you would need 10 strands.

    Also, how is 35 watts half of 123 watts?

    When comparing incandescent to LED lamps, the brightness also needs to be considered. Was that done?

  • Brian W.

    HI: Hope this is the right place to post this. I know its not related to xmas lights. I saw & read the article about how Ups,Fedex & Us mail treats our packages & comparing them on the bases, who treat your packages the best or how gentle each service was. That was great.

    Q:Have you done a story about how either online service treat your packages when they pack a delicate object or electronics? Like or etc…. Reason being that I have heard that treats the thing you purchase terrible especially electronic stuff.

    Thanks in adv

  • Oscar Sall

    PG&E issued a press release and CBS5 turned it into a good question piece. In the original release, PG&E references a US Department of energy report.

    While it may be somewhat correct for other parts of the country, it’s very skewed for the Bay Area. Mike, I’m guessing you don’t have PG&E as your electricity provider.

    If you live in the SF Bay Area, there is no way you can light up a tree for 40 days with 125 lights for 12 hours a day for $27….21 (Let’s adjust to 30 days based on the article for a total of $20.41)

    In PG&E own rate package presented to the CPUC, they state the average PG&E customer uses 550 KWh of electricity per 30 days.

    Let’s calculate what those lights actually cost PG&E customers…

    Winter Baseline is 9.8 KWh per day (The lights alone in the example would use 6KWh per day). If the average is 550KWh, the lights would add another 180 KWh to a PG&E bill, so you’d pay for a grinchly 730 KWh because you put lights on a tree.

    Lat’s add it up shall we…

    550 KWh Baseline @ .11877 = 65.32
    254 KWh 101-130%Base @ 0.01625 = 4.13
    165 KWh 131-200%Base @ 0.1506 = 24.85

    PG&E Energy (less the 20 bucks or more in fees and taxes)

    Now with those power hungry lights, let’s see what SF Bay Area residents would pay.

    730 KWh Baseline @ .11877 = 86.70
    434 KWh 101-130%Base @ 0.01625 = 7.05
    345 KWh 131-200%Base @ 0.1506 = 51.96
    138 KWh 200-300%Base @ 0.1392 = 19.21

    PG&E Energy (less the 20 bucks or more in fees and taxes)

    So people who are fortunate (if not grateful) enough to have anyone other than PG&E as their power provider pay $20.41 for lights on their tree.

    If you put lights on your tree and have PG&E, you pay $70.62 towards their Christmas bonus (3 1/2 times more than anyone in the country).

    Just in time for the new year, PG&E is rewarding you by reducing Baseline usages for SF residents to 9KWh per day for next Christmas and to just 7.5 Next Summer! Happy New Year!

    Who says there isn’t money to be made in energy efficiency. If you save energy, PG&E increases rates to make sure you’ll never get out from under their thumb.

    Just think of how much water PG&E executives will save. They’ll be able to bathe in cash given this latest round of price increases.

    Here’s the source of these calculations

    • Mike Locke

      Thanks for the clarification. I live in Santa Clara and have Silicon Valley power at about $0.08/kwh for baseline and $0.09/kwh for tier2; I’ve never used more than tier 2 power.

      However, the answer to my question is the assumption of 125 4 watt bulbs in the original article, for 1000watts of power. That is a huge power draw that will give off a significant and noticeable amount of heat. It will also give off far more light than 280 LED bulbs, making the comparison unfair.

      The available high brightness LEDs are only slightly more efficient than high efficiency incandescent lamps. However, low wattage incandescent lamps have a lower efficiency than high efficiency incandescent lamps AND the color filter on holiday lamps further reduces their efficiency. LEDs can be designed to directly produce the desired color so that filtering does not attenuate the light. This can be expected to provide about a 10x overall efficiency advantage, such as what is seen compared to the miniature incandescent lamps.

      LEDs are not intrinsically more long lived than incandescent. However, the desired operating parameters are such that they do last longer in practical terms. Incandescent lights are stressed to very close to failure in order to increase the efficiency and improve the color. Higher temperatures would increase the efficiency, but the filament would boil away too fast.

      LEDs can be stressed by trying to increase the brightness. This reduces their efficiency (unlike incandescent) and will cause them to fail quickly because the excess heat will allow the crystal structure of the LED to change.

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