Solar photovoltaics (PV)
Almost all installed solar generating capacity in the world is provided by photovoltaics (PV), which use specially treated thin cells, collected together in panels, to convert the sun’s light into electricity. Most cells are currently made of silicon but alternatives are being investigated.
PV units have traditionally had low generating capacity but can be deployed in many different ways, including on residential roof tops, as an integral part of a building’s structure or in larger numbers on the ground.
Low generating capacity and the need for more distribution and transmission infrastructure pushes up production costs, making PV a good option for off-grid generation, although the flexibility of utilising thousands of different locations is attractive and many governments offer feed-in tariffs in order to make PV economically viable.
The proportion of solar energy converted by PV units into electricity is increasing every year, bringing down the cost of the technology.
At the same time, the increasing popularity of solar panels is driving low manufacturing costs, so the technology is becoming increasingly commercially viable in some industrialised countries and is likely to become a mainstream source of power generation around the world within a decade.
Thus far, PV has mainly been used to provide electricity in off-grid locations around Africa and projects are often funded by non-governmental organisations, perhaps to provide electricity to a school or for refrigeration for medicines.
However, commercial schemes have been developed in North Africa and PV will form as key strand of South Africa’s renewables revolution. Several projects are examined later. Large-scale PV installations are becoming increasingly feasible so the boundary between centralised and decentralised solar power generation has become blurred.