h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

As a confirmed (some would say rabid) greeny, I want to know if the power consumption of (domestic) energy saving lightbulbs is constant, or does it use more power to start it up (like a traditional neon tube)

In effect, I want to know if I should turn 1 off if it is going to be switched on again soon? As I am used to doing for incandescant bulbs, for any length of time.

I appreciate any help you can give

From what I've heard, you should leave them on (I never do, I'm just too used to switch off the light when leaving a room )
I heard recently on the radio, that here (Germany) it depends very much on which energy saving light bulb you buy whether or not you acrually save energy (and money). Some of the tested bulbs gave less light (in W) than claimed and so on.
http://www.test.de/themen/umwelt-energie/test/-Energiesparlampen/1653086/1653086/1654329/

It may be a good idea to look for a comparison/test of them in your country.

I read they should be left on because they take more power to start than to run constantly, but there was a thread about it on h2g2 once which went through a lot of the info and came up with the solution that it's ok to turn them off. Although I still wouldn't turn one on and off for just a few minutes I now don't mind turning my dining room light on while I feed the dogs then turn it off after. Before that thread they always ate in the dark!

Actually that light is on so infrequently I could use an old fashioned bulb just to use them up.

Traveller in Time not always switching out all lights
"Chances of hitting your head or stumbling over something . . .

Anyway, our real life investigators 'The Mythbusters' (from the television series) have performed some tests. Even the lights with most power hunger during startup have to be switched off for no more then 0.14 seconds to save energy.

I have several (single) LED lights I never switch off . . . they are on motion detection switches, using about half the energy of a switched on LED "

OK top 5 hits from googling

'myths about fluorsecent lights'

http://www.consumerenergycenter.org/myths/fluorescent_lights.html

http://64.233.183.104/search?q=cache:RIkLtEKsR5cJ:wattwatchers.org/Assets/flyers/myth%2520v%2520fact%2520update%252010-04.pdf+myths+about+flourescent+lights&hl=en&ct=clnk&cd=4&gl=uk&client=firefox-a

From http://www.ibiblio.org/london/renewable-energy/mailarchives/greenbuilding2/msg00356.html

>>Inrush fact: When fluorescent fixtures are turned on there is a MOMENTARY
inrush of current. This inrush is 5 times greater than normal operating
current for magnetic ballasts and can be as high as 40 times greater than
normal operating current for electronic ballasts. This inrush lasts for
1/10th of a second or less. Thus the energy content of the inrush event is
comparable 5 seconds or less of normal operation. Thus, turning off the
lights for more than 5 seconds will save more energy than leaving them on
even when including the inrush current.<

http://www.lbl.gov/Science-Articles/Archive/energy-myths3.html



The answer is - turn them off!

OK, missed a link there but the point is made.

This is an utter myth, turning on a fluorsecent light of whatever flavour consumes about the same amount of power as leaving it on for about 5 seconds.

Further question, not unrelated...
Life of incandescent lamps

(Ignoring comfort & convenience of using dimmers)

It seems that turning on incandescent lamps at the low setting (dimmer) extends their life (less of a thermal shock). Intuitively that seems reasonable.

Is it?
By how much?
How does it relate to footprint costs of lamp & dimmer?

Thank You all

The reason that I asked is: A long long time ago (When I can still remember when the music used to make me smile) When I was in school, I was told that the neon tubes used in the school sed as much power to start as an hour's worth of being on.

A supplementary question:
Is the life expectancy of energy saving bulbs affected by swithching them on and off more often?

I have found that they do not last nearly as long as I am lead to expect? (both in UK and Thailand) I have always switched them off; even for short periods.

I've lived in my house for ten years and I've changed 2, or possibly 3 (it's a long time to think back on!) - at least two of which came with me from my previous home.

In fact the one in my dining room I think was my first one ever.

Stop calling them Neon Tubes. They are Fluorescent Tubes.

Neon tubes are completely different and used mainly in advertising and require a voltage of around 6 to 10,000 volts to operate.

indeed