What do you plan on averageing?

If you get 1 gram per watt and at any moment, the sun emits about 386,000,000,000,000,000,000,000,000 watts of energy with about 174,000,000,000,000,000 watts of that energy hits the earth with about 76.8% of that energy being visible and in the color spectrum useable to the plant....
14 tons per plant