I need more info' on this: How many led's for say 40 plants? Or, rather, what wattage for 40 plants?
Think of all the different colours of the spectrum you could introduce to the plants. Plants also benefit from green, white, orange light.
I know i'm trying to run before I can walk, but like you said, this is the future of growing. Maybe that's why it's easier for me to want to try something like this because I'm new to it all. It would be much harder for someone like yourself with your thoroughly tried and tested methods to want to try a different method.