Most of the major hydro potential has been developed and they are delivering valuable low cost electricity to the country. Hydroelectricity generation has played a major role in power generation in Sri Lanka, since the commissioning of the first hydroelectric power plant in 1950. In fact, the largest share of electricity generation came from major hydro development projects until the mid 1990’s.
The geo-climatic settings in Sri Lanka are particularly conducive to harnessing hydro resources. Sri Lanka is characterised by a highland mass situated in the south-centre, surrounded by an intermediate zone of upland ridges and valleys lying at lower elevation. The climate of Sri Lanka is largely determined by the meteorological conditions caused in the Indian sub continent due to the tropical circulation. A major phenomenon caused by these conditions is the formation of two contrasting wind regimes, the Asian Monsoons. They are referred to as the southwest (SW) monsoon – prevailing from May to October – and the northeast (NE) monsoon – prevailing from December to February. These are responsible for distinct seasonal rains in Sri Lanka. Given the humid conditions and the hilly terrain, the highlands of Sri Lanka offer excellent opportunities to harness hydropower to generate electricity.
The development of the small hydro power (SHP) sector in Sri Lanka is widely considered to be a success story. The small hydro industry is typically characterised by hydro power projects with a capacities less than 10MW. The economically feasible small hydro potential in Sri Lanka is estimated to be 400 MW.