INTRODUCTION
Nigeria is characterized with large expanse of land with remote, isolated communities located at long intervals whose inhabitants are often peasant farmers living below subsistence level these areas are marked by lack of basic infrastructures like road network, telecommunication, water supply and electricity etc.
Electricity supply in the country has been through centralized generating station (hydro and thermal) with high capacities (above 100MW). The major operators in the Nigerian electric power station is the National Electric Power Authority (NEPA) now the Power Holdings Company of Nigeria (PHCN), which was create in 1972 after the merged of the then Electricity Corporation of Nigeria (ECN) and the Niger Dams Authority by Decree NO. 24 of 27th June 1972. The supply was about 80% of the total electricity consumption in the country with about 6000MW installed capacity from three (3) large hydro power stations, Shiroro, Jebba and Kainji with other five (5) thermal power stations, its maximum suppressed demand is about 3,500MW. The demand for electricity is shared between residential, industrial, commercial/street lighting in the proportions: 50:30:20. , With 2 to 5% of the capacity of the national grid is contributed by private sector -IPP. (NESCO, Shell, AES-Lagos, Bayelsa state gas turbine and Ajaokuta Steel company) all these private producer sells power to PHCN for transmission and distribution to consumers, while the other balance of power demand in the country is been supply by private generating sets.
About two-third of Nigeria lies in the watershed of the Niger River, which empties into the Atlantic at the Niger Delta, with its major tributaries. The Benue in the Northeast, the Kaduna in the North Central, the Sokoto in the Northwest, and the Anambra in the Southeast. The Niger is African's third longest river and fifth largest in term of discharge. Several rivers of the watershed flows directly into the Atlantic notably the Cross river in Southeastern Nigeria and the Ogun, Osun and Oyan in the Southwest.
Several rivers of Northeastern Nigeria, including the Komadugu Gana and its tributaries, flow into Lake Chad. The lake rests in the centre of a major drainage basin at the point where Nigeria, Niger, Chad and Cameroon meet. Kainji Lake created in the late 1960s by the construction of the Kainji Dam on the Niger River in Nigeria. The country's topography ranges from lowlands a1ong the coast and in the lower Niger valley to high plateau in the North and mountain along the eastern border, most part of the country is linked with productive rivers which are scatted virtually all over the country. In Nigeria, electricity is seen as an essential infrastructure in the same category as roads, telecommunication and water. In fact it is the life-blood of our National development and industrial growth. Although electricity is treated as an essential social service. After slightly over 100 years ago the industries is still characterized by erratic supply of inadequate coverage in term of geographical spread covering less than 40% of the population and a record of low per capita consumption.
POTENTIAL HYDRO POWER SITES IN NIGERIA
Nigerian’s Hydro Potential is high and hydropower currently accounts for about 32% of the total installed commercial electric power capacity. The overall large scale potential (exploitable) is in excess of 11,000MW.
Nigeria has considerable hydro potential sources exemplified by her large rivers, small rivers and stream and the various river basin being developed. Nigerian rivers distributed all over the country with potential sites for hydropower scheme which can serve the urban ,rural and isolated communities. An estimation of river Kaduna, Benue and Cross river (at Shiroro, Makurdi and Ikom respectively) indicated that total capacity of about 4,650MW is available, while the estimate for the river Mambillla plateau is put at 2,33OMW.
The first generating plant was built in Lagos in 1898 by the colonial government and was managed by the Public Works Department (PWD). Native and Municipal Authorities thereafter set up understating by 1950, the federal government established electricity corporation of Nigeria (ECN) through the instrument of ordinance No. 15 of 1950, which was vested with the responsibility of running the generating station, subsequently in 1962 the Niger Dam Authority (NDA) was established to built dam.