Hydro power is a renewable, economic, non-polluting and environmentally benign source of energy. Hydro power stations have inherent ability for instantaneous starting, stopping, load variations etc., and help in improving reliability of power system. Hydro stations are one of the best alternatives for meeting the peak demand. The generation cost is not only largely inflation free but also reduces with time as the term loan gets repaid to the lenders. Hydroelectric projects have practically long useful life extending over 40 to 50 years. They also help in conserving scarce fossil fuels and open the avenues for development of remote and backward areas with local employment generation.
India is endowed with enormous economically exploitable and viable hydro potential power assessed to be about 84,000 MW at 60% load factor (1,48,700* MW installed capacity). Further, 56 sites for pumped storage schemes with an aggregate installed capacity of 94,000 MW have been identified. However, only 15% of the hydroelectric potential has been harnessed so far and another 7% is under various stages of development. Moreover, about 78% of the potential remains without any plan for exploitation till date.
Despite hydroelectric projects being recognised as the most economic and preferred source of electricity, share of hydro power has been declining steadily from 44 per cent in 1970 to 25 per cent in 2010. The ideal hydro thermal mix should be in the ratio of 40:60. As per 10th Plan Capacity addition programme of 41,110 MW, about 35% of capacity i.e. 14,393 MW was targeted in Hydro Power. Out of this, only 35% (7,886 MW) has been achieved. As per 11th Plan Capacity addition programme of 78,700 MW, about 20% i.e. 15,627 MW capacity was targeted in Hydro Power. Out of which, 3,561 MW of Hydro capacity is constructed and 6,666 MW is under construction as on July, 2010.
The constraints which are affecting the hydro power development are technical (difficult investigation, inadequacies in tunnelling methods), financial (deficiencies in providing long term financing), tariff related issues and managerial weaknesses (poor contract management). The hydro projects are also affected by geological surprises (especially in the Himalayan region where underground tunnelling is required), inaccessibility of the area, problems due to delay in land acquisition, and resettlement of project affected families, law & order problem in militant infested areas.
While assessing the Hydro Power projects, all these difficulties need to be identified and analysed beforehand. This manual is a guide to critically evaluate the Hydro Power project comprehensively and further provides an overview on the major areas for indepth analysis.