It wasn't energy use that drove me to buying led
It was the price of replacing the fluorescent tubes
At $15 pair, and three pair in five years, different fixtures
I decided to try led and bought the 16 ft strip reel from Amazon that other members were using,
That reel did all my fluorescent fixtures, at about the same price as one pair of tubes, and I haven't had any of the LEDs fail yet
And we full-time, everyone of those fixtures see some use everyday, some more than others, the from one near my desk 4~6 hours every night