The 'Photovoltaic Effect' is the process by which Light Energy is converted to Electrical Energy. The Photovoltaic Effect uses direct and indirect daylight to create electricity from free year-round solar radiation.

Photovoltaic systems use PV Modules or Collectors to harness the sun's radiation. These modules comprise a number of Solar Cells, made up mainly of a semi-conductor, where the Photovoltaic effect actually takes place. There are three main types of PV Modules - Monocrystalline, Polycrystalline and Amorphous Silicone - varying in applications and efficiencies.

PV Systems are usually categorised as "Grid-connected" or "Off-grid". Grid-connected systems are installed in parallel with the main electricity supply. They can range from small domestic supplementary systems (usually 1-3.5kw) to large-scale PV installations called arrays (up to several MW). Grid-connected systems require the installation of inverters to convert the DC electricity generated by the modules to Grid-compatible AC electricity. Feed-in Tariffs and/or Government incentives are also required to make the installation/investment financially viable.

Off-grid systems are usually installed in areas where main grid-connection is difficult, expensive or impossible. They usually incorporate battery storage systems and must be carefully sized to cater for the relevant electricity demands.