The primary [photosynthetic] reactions have close to 100% quantum efficiency (i.e., one quantum of light leads to one electron transfer); and under most ideal conditions, the overall energy efficiency can reach 35%. Due to losses at all steps in biochemistry, one has been able to get only about 1 to 2% energy efficiency in most crop plants. Sugarcane is an exception as it can have almost 8% efficiency.
The primary [photosynthetic] reactions have close to 100% quantum efficiency (i.e., one quantum of light leads to one electron transfer); and under most ideal conditions, the overall energy efficiency can reach 35%. Due to losses at all steps in biochemistry, one has been able to get only about 1 to 2% energy efficiency in most crop plants. Sugarcane is an exception as it can have almost 8% efficiency.