text: what's the truth on fluorescent bulb efficiency? re: turning on & off? ok, i've seen & heard this both ways up from otherwise credible sources recently. but either one is right & other wrong, or vice versa, or they're both wrong. they can't both be right.  standpoint 1: a fluorescent bulb is very efficient, but turning it on is not, and you have to leave it t1urned on for at least 15 minutes if not much longer to burn up the same power required to jolt it into life and produce an arc. therefore turning it on and off repeatedly not only burns up your starter capacitor, but also wastes a lot of electricity.  standpoint 2: turning on a fluorescent bulb uses very little electricity vs leaving it turned on long-term, with the equivalent of 15 seconds being quite excessive.  i'm not sure which camp to go with. not the first, because - where does all that pile of energy go to? that's about 15kwh all in one go for a 60w bulb. it would destroy both the starter and the bulb. but the second seems a little low - you still need a "flashbulb" effect to get the arc...!? a fluorescent tube has filaments at each end that have to heat up to vaporize the mercury necessary to start the tube.  since they start so fast, the starting doesn't really cost that much more in electricity usage.  however, the ballast on the twin 40 watt tube fixture uses about 20 watts by itself.  thus, two 40 watt bulbs require 100 watts to operate.  once the tube has started, the filaments are no longer activated and no longer consume power.  since they burn hot, turning the bulb on and off will shorted the life of the tube.