I am a maintenance man by trade and I deal with a lot of light bulbs and I'm always reading the packages. I've noticed that they say a 13w cfl is the equivalent of a 60w incandescent but the 13w cfl puts out significantly less lumens. They say a 9w led is comparable to a 13w cfl but again the lumen count is down. I know lumens aren't the ideal measurement for plants but the fact remain that there is less light in each comparison. Its been my observation that when it comes to bulbs you need almost as many led watts as you do cfl watts to make the same amount of light. Being more efficient the led bulbs will generate less heat.