Fluorescent lights get dimmer with age. We installed new T8 Lamps in our shop several years ago. To save energy, we only used the odd-numbered lamps and left the even-numbered lamps turned off. Recently we turned on the even-numbered, seldom used lamps and noticed the difference. Then we tested the twisty CFL lamps and noticed that not only was the year-old CFL dimmer than a new one, but it used more power.
