Solar photovoltaic (PV) panels contain semi-conductors such as silicon, which convert solar radiation into electricity. The DC (direct current) electricity produced is then (usually) fed through an inverter to produce AC electricity at a voltage and frequency suitable for general use.
Electricity produced by solar PV panels is noiseless, 100% emission free and almost always FAR cheaper than buying it from an electricity supplier. Solar PV systems operate year-round, and need virtually no maintenance. They are suitable for mounting almost anywhere they can be secured – but there are a few reasonable caveats as follows.
Solar PV panels work best when they are facing between east and west (through south). Panels facing further north than due east or west will still work, but at far lower efficiencies. They can be mounted vertically (or even horizontally*) – but they work best when inclined at between 25 and 45 degrees. This inclination happens naturally when the panels are mounted on a pitched (sloping) roof – on flat roofs or on the ground we would use a frame to incline the panels to the desired angle.