A single cell can produce a small voltage. Many cells must be linked together to produce a usable voltage and current. Solar cells are used primarily in satellite and cameras. The high cost of construction has limited their general application. Light energy can be converted directly to electrical energy by light striking a photosensitive (light-sensitive) substance in a photovoltaic cell (solar cell) When the surface of the photosensitive material is exposed to light, it disiodges electrons from their orbits around the surface atom of the material, because light has energy