In article , mm wrote:
Which uses more electricity, a 75 watt light bulb, or a 150 with a
dimmer so that it is only as bright as the 75?

If one uses more, does it use much more?

A 150 watter dimmed to the brightness of a 75-watter consumes about
or maybe a bit under 100 watts. Given the dimmer likely to "lose" a watt
or two in the process, I would say that a 150-watter dimmed to the
brightness of a 75-watter ends up consuming close enough to 100 watts.

Assuming a 10 cent per KWH electricity cost, that extra 25 watts over
the 750 hour rated average life expectancy of a "standard" 75W lightbulb
costs $1.87. Even if the lightbulbs are at a "convenience store price" of
$1.15 apiece and only average 500 hours actual life, you pay more if you
even completely eliminate burnouts with 25 watts more power consumption
per lightbulb.

- Don Klipstein )