If the efficiencies of P.V. panels ever reach the efficiency of today's heating collectors, and the costs are kept down, the energy usage on earth will be dramatically changed. The basic building block of photovoltaics is the cell. Cells are either round or square and convert sunlight to D.C. electricity. The photons of light cause electrons to flow in the cell which is usually made of a doped silicon crystal. The current produced by each cell depends on its size.
Most cells manufactured today produce from two to four amps of current.
Cells are normally wired together to form a module or panel . These are called 12 volt modules because they are used to charge 12 volt batteries . Two or more modules is called an array. Modules, like the cells that they contain, may also be wired in series, parallel or both. How cells and modules are wired give a designer a wide range of voltage and amperage outputs.