09d9bdb1_den__Solar_Cells_Versus_Leaves__The_Solar_Cell
[0] Efficiency [The Leaf] According to some estimates photosynthesis absorbs about three to six percent of all solar radiation that hits Earth. In reality photosynthesis is not overly efficient. If it was one hundred percent efficient leaves would appear black in color. Instead only a small fraction of needed energy is absorbed. [The Solar Cell] 
The current record holding efficient solar cell was about 42% efficient. However, these ultra efficient solar cells are extraordinarily expensive, and therefore not practical for general use. Most common solar cells are only 13-16% efficient, even less efficient than fossil fuel power generation.
Experiment Garden: Solar Cells Versus Leaves
The Solar Cell