Well that depends on the style of light, if they're the screw in spiral flourescents. Then no due to the shape of the bulb, you're at best getting 50% (and that is with a perfect reflector - something you wont even get at NASA) Even with the standard flourescent tubes, you're still not getting 30w because half the light is getting blasted up to the canopy. There are flourescents which only the bottom half produces light, but they're expensive and you still loose some light.