Does it take more electricity to turn the light on than it does to leave it off & turn it back on?

Question

I've been told Turning ON a light uses more electricity than actually Leaving the light on. Is that true?

Answer 1

Several variations of this was done on Myth Busters. basically, if you don't need a light on, turn it off. The breakeven point is reached in under a second. Some fluorescent bulbs use a starter circuit, but again the energy savings of not making a second start is very quickly eaten up by the power consumption of letting the light burn.

As a rule of thumb, the time the starter acuates will be roughly the time you could save without restarting. Two seconds to start or two seconds of running. will cost the same.

Answer 2

No, leaving a light on is like leaving your headlights of you car on, it will use tons of electricity but if you turn your lights off it reserves the electricity. The tungsten filament doesn't need extra power to heat up and make light, the light is the result of friction from the electricity flowing through the filament. the bulb uses the same amount of power and the current draw is mi nut.

leaving on a light uses constant electricty , a light that is off uses none .

leave on your lights for a month and tell me the difference in your power bill.
HEHEHE

Answer 3

It used to be that early fluorescents took a fair amount of electricity to start, so it made sense to leave them on, if not using that area for a short time, but this is not so true, now, with modern improvements, so replace all your incandescent lights with low wattage fluorescents, and turn them off when unused. In Australia, we are banning incandescent bulbs soon, as they cause far too much greenhouse gases to be produced, and the electricity and $ savings are considerable, too.

Answer 4

Not really true. Incandescent bulbs will draw a heavier current as the filament heats up, but that is only for a few milliseconds. Flourescents will draw even more for the second or 2 that it takes for them to ignite and stabilize, but again, we're only talking about a couple of seconds of on-time.

But turning on either does use up a significant bit of their life, especially flourescents. For floescents, I dn't turn them off unless I'm planning on leaving it off for at least a few hours. And to greatly extend the life of incandescents, I have dimmers everywhere so that they come up slowly (as in say 1/2 second, the time it takes you to turn the knob) and try to never leave them all the way on. Huge difference in bulb life, maybe a factor of 5 or 10.

Answer 5

That theory is not 100% correct(i think) see it does take somewhat more electricity to turn the light on than when it runs but no matter how long the light is on for you will be charged so......

Answer 6

Depends on how long it's going to be off. There *is* a thing called 'inrush current' that's about 20 to 50 percent greater than 'steady state' operating current. But it only lasts a tenth of a second (or less) so the light would have to be off for a very short period indeed.

Doug

Answer 7

Well, there is a break-even point, no doubt. I'm guessing it's not that long, however. Like, if you leave it on for more than 30 seconds, it uses more electricity.

Answer 8

gentle bulb existence (and fluorescent tube existence, for that count number) is more beneficial useful measured by ability of the style of switching operations it may bear, particularly than the style of hours that's going to very last if run continually. more beneficial useful yet can be a mixture of both measures. oftentimes this argument is utilized to fee performance particularly than power performance. it may be shown that there is a spoil-over fee between operating a tender continually and typical switching. by ability of extension, it may likely be shown that there is likewise a spoil-over in power criteria on my own, more beneficial so for fluorescent than incandescents because of their more beneficial fee of manufacture. in the course of the flexibility disaster of the '70's study of this difficulty finished by ability of accountable human beings were revealed in commerce journals. The consensus on the time replaced into that in case you recommend to reenter a room in decrease than 1/2-hour that's more cost-efficient to leave the gentle on than as an instance it off and turn it back on. For power stability (leaving out salary) the frequency of operation may should be a lot shorter.