Types of PV Systems
      PV technology was first applied in space, by providing electricity to satellites. Today, PV systems can be used to power just about anything on Earth. PV systems operate in two basic forms.

      Grid Connect PV Systems - These systems are connected to a broader solar electricity network. During the day, the solar electricity generated by the system is either used immediately or sold off to electricity supply companies. In the evening, when the system is unable to supply immediate power, electricity can be bought back from the network.

       Stand-Alone PV Systems - These systems are used in isolation of solar electricity grids, and may be used to power radio repeater stations, telephone booths and street lighting. There is also a growing market for mobile PV in the boat and caravan leisure market. Stand-alone PV systems also provide invaluable and affordable electricity in the developing world, where conventional electricity grids are unreliable or non-existent.