Power usage...

[Aussie_Paul]

A question re the normal old 4' fluro tubes. How much energy do they use on start up, and how much do they use per hour while running continuously. Trying to work out if they should be switched off every time, or does switching them on often use more energy?

Aussie Paul.

[JEFF TIPTON]

How about this article.

So you bought a compact fluorescent lightbulb in a bid to be green. Such bulbs are vastly more energy-efficient than traditional incandescents and screw into standard sockets. Should you treat them like their older cousins?

After all, four- and eight-foot- (1.2- and 2.4-meter-) long tubular bulbs common in more institutional settings are sometimes left on permanently, perhaps due to their slow, flickering start-ups. The thinking is that the boost of energy such bulbs require to power up means that it might be best to keep them on when leaving a room, rather than subjecting them to the stress of a restart on your return.

Turns out, however, that power surge is so brief that its energy draw doesn't amount to much: the equivalent of a few seconds or so of normal operation, according to U.S. Department of Energy estimates. In other words, from a strict energy-conservation standpoint, it's almost always beneficial to shut off fluorescents when leaving the room—the start-up energy is offset by the power saved in even the briefest outages.

But what about the wear and tear on the bulb itself? Being too switch-happy reduces the operating life of the lamp, and given that newer fluorescents are still a few times more expensive than old-fashioned incandescents, it makes sense to forestall burnouts. There are also real environmental impacts of their production and disposal to consider.

A simple rule of thumb that balances both concerns is to shut off fluorescents if you’re planning to leave a room for more than five minutes, according to Francis Rubinstein, a staff scientist in the Building Technologies Department at Lawrence Berkeley National Laboratory's Environmental Energy Technologies Division. Mary Beth Gotti, manager of the GE Lighting & Electrical Institute in Cleveland, agrees. For all practical purposes, "it almost always makes sense to turn the lights off," Gotti says. "From an environmental standpoint, the best way to save energy is to turn off the things that you're not using."

Rubinstein notes that, even for fluorescents, the cost of electricity over a bulb's lifetime far outpaces the cost of the bulb itself. "Even if you switch on and off a fluorescent light frequently," he says, "the slight reduction in lamp life is a small effect relative to the energy savings you accomplish by being a good citizen." Gotti adds that the reduction in lamp life from frequent on-and-off switching can often be counterbalanced by the extension of "calendar life"—the actual passage of time between lightbulb replacements—that results from using the bulb for fewer hours.

That sort of calculation will probably become more common as compact fluorescent lightbulbs come down in price, cast more pleasant light and, most importantly, force their power-hungry competitors from store shelves. The Australian government will phase out the sale of traditional incandescents in that country by 2010, and the U.S. Congress has effectively mandated the same ban domestically by 2012. But whereas that new fluorescent bulb is sure to lower utility bills in your home, the real energy-crunch savior has been there all along: the light switch.

http://www.scientificamerican.com/ar...you-leave-room

[hillberg]

What savings? Just saw some Hi Tech CFLs @ $60 each, Scam lies & WTF.

[REDHORSE556CES]

With the incandescent bulb about to go the way of women's high-top, button up shoes and bustles; there is one more thing you need to know.

You buy all those CFLs and LED bulbs and, sure enough you cut down on your energy usage. But if you go snooping around in Federal Energy Regulations you'll find a little passage that lets the energy producers increase the price of your electricity to offset the drop in power consumption.

Ain't life grand?

[JEFF TIPTON]

Also; if I am not mistaken CFL's contain mercury. They should be disposed of hazmat, not in the trash can.

[Master Roda]

I use open windows and old oil lamps. If I really need some light at night I use the TV

[Aussie_Paul]

I am asking about the old fluro design that we have been using for 50 odd years that have a ballast resister??? and a starter.

Aussie Paul.

[Oskar]

Been playing with lights for a while, here’s the down to earth answer:

The energy used depends on how long the lamp is on for. For the same light output as a 100W incandescent bulb, a fluorescent bulb would use about 0.02kWh of energy per hour. In Ozzie the price of electricity would be somewhere in the order of 20c/kWh which means the fluorescent light will use about 0.4c of energy per hour.

But here’s the catch:

Typically the lifetime of a incandescent bulb is about 1000 hours and fluorescent bulb about 10000 hours. The life of a fluorescent bulb is, however, significantly shorter if it is turned on and off frequently. In the case of a 5-minute on/off cycle the lifespan of a fluorescent can be reduced to close to that of incandescent light bulbs.

Which means that if you switch the fluorescent light on and of every 5 minutes the bulb will need replacing after having used only $4 of energy.

The happy balance is probably to leave the lights on if you’re gone for less than 10 to 15 minutes.

[James]

Post # 4, you are right. The less you use the more they charge. It is a fact.

[Brent Drake]

I deal with these lamps and federal mandates everyday.
Paul, Yes the old style of fluorescent that you have last longer with the separate starter.
But after approximately 15 seconds the power usage drops to normal power. The new T-8 style lamps do much better at using less energy. The new T-5 style is the best on energy usage now. Only thing better is LED
Here in the US now July 14,2012 all T12 and T8 lamps basically will no longer be made. There are several rebates available for people wanting to switch early.
The only T8 lamp that will still be produced is the one that produces 2850 lumens.

[Arnie Madsen]

Paul .... my auto-body business was well-lighted with lots of 8 foot florescent fixtures placed close together.

About every three days at least one bulb would start to flicker and go dead. New tubes were about $4 at the time.

Then about every 2-3 months I was replacing at least one ballast resister .... about $49 each.

I didn't mind the cost so much .... I just hated having to get the ladders out to change parts ... and I hated the flickering bulbs all day long.

I calculated the lights used a very small amount of electricity .... and if I left them on 24 hours a day .... it would cost me only about $14 per month extra. I checked with my electric company and they confirmed my figures.

We have left those lights on full time for 30 years ... and problem solved.

A lot of highrise office buildings now do the same. Otherwise they need a full time employee to change bulbs .... and he still could not keep up.