Which uses more electricity turning switches on an off, or just leaving the light on ?

Question

Which uses more electricity turning switches on an off, or just leaving the light on ?

Answer 1

It depends.Switching on and off is harder on the bulb(surges and rapid temperature change) an incandescent bulb's resistance increases(so less current) as it gos from dark to bright so that most current is used per unit of time when the bulb is first turned on.However one must consider the off time.

Answer 2

By far turning things off saves electricity. The only exclusion is appliances that has a start up mode where a lot of electircity is used then decreases once the appliance is running. Lights are on & off so turning off is always a good idea.

Answer 3

In general everything worth to turn it off to save energy, except it you are willing to turn them on again in 3 to 5 seconds.

The only exceptions are those things that take time to comes to a "ready" form for you to use.  One clear example is your Personal Computer.  It takes almost 1 to 2 minutes to complete the boot and allows you to use it.  So, if you are planning to leave your computer on for more than 10 minutes without use, it is better to make it sleep (not power off).  You can program it to sleep, it reduces power consumption in almost 85%, turning off the hard disks and monitor screen.

Other than that, turn it off.

Remember, there are some electronic equipment that MAY cause component damage and premature failure if you keep turning it on and off frequently.  Again, for example, your Personal Computer, its power supply is usually low cost and built to run for few years, under "normal" circumstances, it does NOT mean forcing it for the surge currents of power on every hour or so.  If you do that, it will fail in less time than expected.   I personally only turn off my office computers every week or so, just for the weekend or maintenance and internal cleaning (every couple of months).

Answer 4

leaving the light on for more than 2 or 3 minutes uses mor power than turning them off.

Answer 5

With incandescents, leaving them on uses more power, although on and off too often stresses the filament.

With fluorescents, the starter builds up the charge, using more power to get it going, then it slows to a trickle. So if it's going to be off for less than 10 or so minutes, turn it off to save power.