14 ms·

Turning the bulb off for just 200ms might be increasing energy usage by itself. I know in older bulbs you had to leave them off for so many seconds/minutes bef

Turning the bulb off for just 200ms might be increasing energy usage by itself. I know in older bulbs you had to leave them off for so many seconds/minutes before you gained any savings by turning them off. The amount of energy it takes to get them going far exceeds the amount needed to keep them running. There is also the problem of the bulb wearing out faster because of the constant switching on and off.

londons_explore 5y ago
For a modern (led) bulb there is effectively zero wasted energy by turning it off and on, but it depends how you define waste. Does light emitted after the switch is turned off count as waste? (Most bulbs take a few hundred ms to turn off)
IgorPartola 5y ago
Minutes? I would like to see the math on that one.
- minitoar 5y ago
  For a CFL, it’s about 15 minutes. https://www.energy.gov/energysaver/save-electricity-and-fuel/lighting-choices-save-you-money/when-turn-your-lights https://www.energy.gov/energysaver/save-electricity-and-fuel...
  - wlesieutre 5y ago
    Note that this has nothing to do with saving energy and everything to do with reducing wear on the bulb from on/off cycles. > The operating life of CFLs is more affected by the number of times they are switched on and off. You can generally extend the life of a CFL bulb more by switching it on and off less frequently than if you simply use it less. > In any case, the relatively higher "inrush" current required lasts for half a cycle, or 1/120th of a second. The amount of electricity consumed to supply the inrush current is equal to a few seconds or less of normal light operation. Turning off fluorescent lights for more than 5 seconds will save more energy than will be consumed in turning them back on again. For this specific discussion about turning lights off while you blink, yes, you do actually burn more electricity in addition to wearing the bulb out if you're cycling it off for just 200ms. But for real world use by normal people, turning off for 5 seconds will save energy, and turning it off for 15 minutes will save money.
    - minitoar 5y ago
      In the real world most people care about saving money. Whether that’s due to wear on the bulb or extra energy consumption is irrelevant.
      - Shikadi 5y ago
        In the real world people care about both actually.
        minitoar 5y ago
        I submit that there are vanishingly small number of individuals who would spend more on bulbs than what those bulbs would save in electric costs over their lifetime.
      - wlesieutre 5y ago
        In the real world people don't care if their CFLs burn out and get replaced with LEDs because CFLs are comparatively terrible and you can get a higher quality LED bulb for about $5.
        minitoar 5y ago
        True, I was just trying to explain this to my partner who didn’t want to throw out still functional CFLs. In this case the value of the estimated remaining life of the CFL + cost of new LED is less than the expected power savings of the LED.
    - Dylan16807 5y ago
      That's going to depend on the design of the bulb. If it's off for the length of a blink, it probably doesn't need to strike again. Or you could dim it to 10% for the duration instead of turning it off. But the other factor is dealing with the delayed response of the phosphor. Can you actually turn the light output off and on fast enough?
    - lupire 5y ago
      Outside of monopoly rent seeking, money is made of energy. That's what you're paying for when you buy something.
kevincox 5y ago
IIRC for incandescent it was about 1/3s to break even. For fluorescents it is likely higher but don't have a source (it may not be an issue if the starter is smart enough to realize that it isn't needed or not needed as much). However there is going to be extra wear and tear on these bulbs which makes the savings offset by extra bulb replacement. For LED the cost of turning off should be very near to zero so this would likely actually save resources. Of course this idea is awful for other reasons. But it is very funny.
- tlarkworthy 5y ago
  no the blink detector is not free and massively adds to the overheads compared to the LED output.

londons_explore 5y ago

For a modern (led) bulb there is effectively zero wasted energy by turning it off and on, but it depends how you define waste. Does light emitted after the switch is turned off count as waste? (Most bulbs take a few hundred ms to turn off)

IgorPartola 5y ago

Minutes? I would like to see the math on that one.

minitoar 5y ago
For a CFL, it’s about 15 minutes. https://www.energy.gov/energysaver/save-electricity-and-fuel/lighting-choices-save-you-money/when-turn-your-lights https://www.energy.gov/energysaver/save-electricity-and-fuel...
- wlesieutre 5y ago
  Note that this has nothing to do with saving energy and everything to do with reducing wear on the bulb from on/off cycles. > The operating life of CFLs is more affected by the number of times they are switched on and off. You can generally extend the life of a CFL bulb more by switching it on and off less frequently than if you simply use it less. > In any case, the relatively higher "inrush" current required lasts for half a cycle, or 1/120th of a second. The amount of electricity consumed to supply the inrush current is equal to a few seconds or less of normal light operation. Turning off fluorescent lights for more than 5 seconds will save more energy than will be consumed in turning them back on again. For this specific discussion about turning lights off while you blink, yes, you do actually burn more electricity in addition to wearing the bulb out if you're cycling it off for just 200ms. But for real world use by normal people, turning off for 5 seconds will save energy, and turning it off for 15 minutes will save money.
  - minitoar 5y ago
    In the real world most people care about saving money. Whether that’s due to wear on the bulb or extra energy consumption is irrelevant.
    - Shikadi 5y ago
      In the real world people care about both actually.
      - minitoar 5y ago
        I submit that there are vanishingly small number of individuals who would spend more on bulbs than what those bulbs would save in electric costs over their lifetime.
    - wlesieutre 5y ago
      In the real world people don't care if their CFLs burn out and get replaced with LEDs because CFLs are comparatively terrible and you can get a higher quality LED bulb for about $5.
      - minitoar 5y ago
        True, I was just trying to explain this to my partner who didn’t want to throw out still functional CFLs. In this case the value of the estimated remaining life of the CFL + cost of new LED is less than the expected power savings of the LED.
  - Dylan16807 5y ago
    That's going to depend on the design of the bulb. If it's off for the length of a blink, it probably doesn't need to strike again. Or you could dim it to 10% for the duration instead of turning it off. But the other factor is dealing with the delayed response of the phosphor. Can you actually turn the light output off and on fast enough?
  - lupire 5y ago
    Outside of monopoly rent seeking, money is made of energy. That's what you're paying for when you buy something.

kevincox 5y ago

IIRC for incandescent it was about 1/3s to break even. For fluorescents it is likely higher but don't have a source (it may not be an issue if the starter is smart enough to realize that it isn't needed or not needed as much). However there is going to be extra wear and tear on these bulbs which makes the savings offset by extra bulb replacement. For LED the cost of turning off should be very near to zero so this would likely actually save resources. Of course this idea is awful for other reasons. But it is very funny.

tlarkworthy 5y ago
no the blink detector is not free and massively adds to the overheads compared to the LED output.