A natural resource is called an energy resource if it can be converted to a usable form of energy. An energy resource is known as an ‘indigenous energy resource’ when it originates within the country. It is known as non-indigenous if it originates outside the country. Renewable Energy is a form of energy resource that is replaced by a natural process at a rate that is equal to or faster than the rate at which that resource is being converted to other usable form such as electricity.
Due to the geo-climatic conditions, Sri Lanka is blessed with several forms of energy resources. Sri Lanka is an island located in the tropics and surrounded by the Indian Ocean. The island receives rain from two monsoonal wind regimes, viz., the Southwest and Northeast monsoons. The island itself is characterised by a central highland, lowland mountain ranges, flat terrains and plateaus, which affect cloud formation. The annual mean rainfall ranges from 750 to 5000mm, which in turn sources a perennial river system. The high rainfall, coupled with other bioclimatic conditions of the tropics, has yielded a high plant density in the island. Biomass therefore, is available in plenty. Since Sri Lanka is located in the equatorial belt, it receives a year round supply of solar irradiation. The tropical temperatures and the island's location in the ocean have resulted in distinct wind regimes. These settings have endowed the country with an ample RE resource base.
Some of these RE resources are widely used and developed to supply the energy requirements of the country. Others have the potential for development when the technologies become mature and economically feasible for use. Following are the main RE resources available in Sri Lanka.
Sri Lanka’s electricity sector is heavily dependent on hydro power. We have been developing hydro power to supply elecricity to the grid since a long time back. All these hydro schemes were major power generation projects and they are also known as ‘conventional’ power generation schemes since they have been around for quite a long time. Now however, the capacity of such large schemes has been almost exhausted. Therefore we have to resort to other means of generating power, among which of small hydros, wind power generation schemes and solar projects are receiving much attention. Such technologies were termed non-conventional renewable energy (NCRE) technologies, because they were not used in the past in conventional grid power generation. Now all renewable energy technologies except storage reservoir type major hydropower are returned to as New Renewable Energy(NRE).