Psh, full daytime spectrum? Energy efficient?
Link
LEDs would be efficient - 92% red, 8% blue, but maybe with a few IR and UV LEDs here and there, and those plants should be set to go. THAT is the NASA way.
In the picture, all that green light that's hitting them, and a lot of the blue light, is just wasted energy - most of it is reflected off of the leaves.