What happens when the pv cell is shaded

Each solar cell in an array pushes electrons from one side of the cell to the other, adding voltage as it does so. However, a single cell isn't extremely powerful, so in order to get the needed voltage numerous cells are needed. 
When a cell is shaded, the number of electrons it can produce is reduced. And if the number of electrons produced in a cell reduces so does the number of electrons produced in the neighboring cell.