Application potential of solar and mini-hydro energy sources in rural electrification

Renewable energy sources are increasingly being considered as viable alternatives to conventional supply systems, in the provision of electricity to isolated communities, especially in the rural areas. Traditionally, rural loads are supplied from either stand-alone diesel power stations or via grid extensions. Such sources are sometimes not cost-effective due to the high fuel and maintenance costs of diesel stations, as well as, long distances from the grid to the loads. Provision of electricity to rural areas is considered uneconomical by many utility companies, because of the low consumption and poor load factors. On the other hand, renewable energy sources, such as solar, wind and mini-hydro, are suitable for supplying small loads operating independently. Also, they are, in most cases, available in abundance in rural areas. The main disadvantage of such sources is the initially high capital costs of the energy conversion equipment, and the variable power output. However, if appropriately applied individually or in combination, renewable energy sources have the potential to be cost-effective sources for some of the rural loads. An assessment of mini-hydro and solar energy sources shows that the energy unit cost decreases with increasing load factor, and it is lower for the mini-hydro sources. In areas where grid supply is uneconomical or not available, mini-hydro sources can be used to supply groups of households, while solar energy sources are more suitable for supplying individual households.