How many of those 10,000 lumens of energy were actually being absorbed?

A customer has a question and I hope we can get some opinions on it, thanks

“I read from a fairly reliable source that direct sunlight provides about 10,000 lumens of light energy, per square foot. Now since plants primarily soak up blue and red wavelength light, and mostly reflect green light, I was wondering how many of those 10,000 lumens of energy were actually being absorbed, as opposed to reflected.”

Google may help some. ‘How much useable light can a plant take from the sun in lumens?’