A third of the world's population, more than two billion people are without electricity. With reduced financial resources and low energy needs, these people are generally excluded from any main grid extension. In such areas, population density is low and this means main connection costs are prohibitive. There are many regions in which solar power is the only solution for providing power to these communities. It is a part of the development of these populations which helps slow the exodus towards the already overcrowded urban areas. Major applications include power supply to community centers such as clinics, schools and drinking water supply. Domestic solar power also remains very popular with individual solar home systems (SHS) power supply kits for lighting, refrigeration, television or radio. Over the last few years, mini-grid projects have sprung up to supply power to whole villages using photovoltaic power plants.
How it works
In general, solar power is useful for supplying electricity in rural areas. There are, however, some limitations. Firstly, the power provided by the systems is low, compared to a traditional main grid. Photovoltaic electricity cannot supply enough power for cooking, heating, or any other job that requires large amounts of power such as welding or grinding maize. However, solar power is sufficient for lighting, radio, television, telecoms and small scale pumping and refrigeration systems. For reference, to supply a household system in Africa with 4 lights (11 W – 2 hrs/day), a television (50 W – 3 hrs/day) plus a socket to supply small electrical equipment (10 W – 1 hrs/day), a total daily consumption of approximately 250 Wh/day, in theory, a 75 Wp module is required, that is, 0.75 m² solar cells.
Technically and financially, solar power provides the most appropriate alternative for power supply in rural areas. Solar kits are simple to use and of low cost to run in the medium and long term (zero maintenance cost). Their reliability (no moving parts), long life (solar cell life of more than 30 years) and the modular construction make them ideal for many different applications.
Major community applications
The main solar power applications in rural areas are:
Schools
To supply a school in Africa with 16 lights (11 W – 8 hrs/day), an overhead projector (50 W – 3 hrs/day) plus a socket to supply small electrical equipment (25 W – 2 hrs/day), a daily consumption of approximately 1,600 Wh/day, in theory, a 500 Wp solar field is required, that is, 5 m² solar cells.
Clinics
To supply a clinic in Africa with 16 lights (11 W – 8 hrs/day), an examination lamp (20 W – 4 hrs/day), a refrigerator for vaccines (600 Wh/day), a single sideband radio (500 Wh/day) plus two sockets to supply small electrical equipment (25 W – 2 hrs/day), though, a daily consumption of approximately 2,700 Wh/day, in theory, a 850 Wp solar field of is required, that is, 8.5 m² of solar cells.
Typical applications
 |
 Typical applications shown above include solar-powered lamps, schools and villages. |