On Wed, 07 Jan 2009 07:21:47 -0600, Jim Redelfs
wrote:

A long time ago, SOME of us learned that constantly turning-on and
turning-off a lamp was usually more expensive than leaving it on. This
hasn't changed.


This is bull****. Turning on and off an incadescent light does not
use more energy, and if the off period is more than a few seconds,
energy will be saved. It's known that flashing christmas lights use
less power than when they are on all the time.

I'd think the same would be true for florescent and halogen lighting.
Now these mercury vapor lights are another story, they need to cycle
up to full brightness and that takes several minutes.

On the other hand, turning on an off a motor is a different matter.
Motors draw a heavy current when they start, so it's best to leave the
motor running if it's only off for a brief moment. Of course if it's
going to be off for an hour, then it's better to turn it off.