How do plants compare to solar cells specifically, when it comes to collecting the Sun’s Radiat Energy (photons)??
2 thoughts on “Solar Energy?”
thedrunkenmaster333
I agree with the 1st answer
Engineer-Poet
Solar cells (PV) are much more efficient than the average vascular plant.
Example: Maize produces about 150 bushels (8400 lb, about 3.8 metric tons) of grain per acre per year, and another 2 dry tons of leaves and stalks in excess of the requirement for erosion control. The embodied energy in this (at 392,000 BTU/bushel for the grain and 17.4 GJ/ton for the other matter) is about 97 GJ/acre/year (sorry about the funny units, multiply by 2.47 to convert acres to hectares).
An acre in mid-Kansas receives about 1550 kWh of sunlight per year; at 15% conversion efficiency in a PV, that’s 232.5 kWh (837 MJ)/m²/year. Multiply by 4047 m²/acre, and you’d get 3.39 TJ/acre/year.
I agree with the 1st answer
Solar cells (PV) are much more efficient than the average vascular plant.
Example: Maize produces about 150 bushels (8400 lb, about 3.8 metric tons) of grain per acre per year, and another 2 dry tons of leaves and stalks in excess of the requirement for erosion control. The embodied energy in this (at 392,000 BTU/bushel for the grain and 17.4 GJ/ton for the other matter) is about 97 GJ/acre/year (sorry about the funny units, multiply by 2.47 to convert acres to hectares).
An acre in mid-Kansas receives about 1550 kWh of sunlight per year; at 15% conversion efficiency in a PV, that’s 232.5 kWh (837 MJ)/m²/year. Multiply by 4047 m²/acre, and you’d get 3.39 TJ/acre/year.