Green plants use about how much of the energy of the sun?
They don't " use" any of the sun's energy.
they turn the energy from the sun into food for themselves.=)
I would say about 80 percent at most. This is because some of the energy gets lost before it reaches the leaves. When energy is absorbed into the plant, some of it as expelled. For mare information, go to http://www.ftexploring.com/me/me2.html.