Solar panels are made up of solar cells – like the ones you see on a calculator – called photovoltaic (PV) cells.
When sunlight strikes the cell, a certain portion of it is absorbed within the semiconductor material. The energy of the absorbed light is transferred to the semiconductor and knocks electrons loose, allowing them to flow freely.
PV cells also have one or more electric fields which force these freed electrons to flow in a certain direction. This forms a current, and by placing metal contacts on the top and bottom of the PV cell, this current can be drawn off for external use.
The current, together with the cell’s voltage (which is a result of its built-in electric field/s), defines the power (or wattage) that the solar cell can produce.
Groups of cells are connected electrically and packaged into a frame known as a solar panel, and these panels are then grouped into larger solar arrays.