International Journal of Engineering Trends and Technology (IJETT) – Volume 23 Number 8- May 2015 ISSN: 2231-5381 http://www.ijettjournal.org Page 391 Small Hydro Power and its Potentiality in Assam Debashish Ranjan Nath #1 # P.G. Student (ME 2 nd Semester), Production & Industrial Engineering, Department of Mechanical Engineering, Jorhat Engineering College, Garmur, Jorhat, Assam, India Abstract— Small Hydropower is a Renewable non-polluting and environmentally benign source of energy. This study is intended to illuminate in terms of technology, power generation and installation of small hydro power plants particularly in Assam, which is very much suitable as an alternative to big dams, detrimental to the sensitive ecosystem of the region. It is reported that Assam has a hydropower potential of the order of 541 MW against which only 2.00 MW has been harnessed. The hilly areas of the State have good hydro potential as small streams can be harnessed for decentralized power generation through small hydro development. Due to lack of road communication in the difficult terrains, where most of small hydro sites are located in the state, the tapping of this resource has become difficult. Keywords— small hydro power, hydro power potential in Assam, installed capacity, megawatt (MW), renewable energy, power, Karbi Anglong I. INTRODUCTION Small Hydro Power (SHP) projects are those that produce electric power not more than 25 megawatt (MW). It is further divided into three classes – small, mini and micro power plants. Power plants up to a capacity of 100 kilowatt (KW) are called micro power plants. Hydro power plants that are anywhere between 100 KW and 2 MW are termed as mini hydro power plants. Those that have a capacity more than 2 MW and up to 25 MW are small hydro power plants. SHP plants differ from bigger hydro power plants in terms of scale. While the large hydro power project needs huge area to create a captive lake that leads to displacement of people, small hydro do not have any such requirements – an entire SHP plant can be set up in a small area in the order of just 2 acres. In fact, the land requirement in SHP is never more than 3 to 4 acres. [1] II. TYPES OF SMALL HYDRO POWER Mode of operation of Small Hydropower plant can be distinguished from the point of view of water flow in three Schemes [2] : A. Run Of River i. No storage ii. The output is subject to instantaneous flow iii. Reliability of discharge and geological conditions should be ensured B. Canal Based i. Utilizes the fall and flow in the canals ii. May be planned in main canal or in bye-pass canal iii. Nearby drops should be clubbed in existing canals iv. In canals under planning concentrated drops should be considered C. Dam Based i. Dam toe schemes are most common in India ii. Water stored during monsoon is utilized for power generation III. SMALL HYDRO POTENTIAL IN ASSAM Development of small hydro in India dates back to 1897 with setting up of the first hydropower plant in India 130 Kilo Volt (kV) capacity in Darjeeling known as Sidrapong small hydro power station to supply electricity to the local areas in a decentralised manner [2] . Assam is situated in the North-East of India and is the largest north eastern state in terms of population while second to Arunachal Pradesh in terms of area. Assam is encircled by six north eastern states, viz., Arunachal Pradesh, Manipur, Meghalaya, Mizoram, Nagaland and Tripura, and another state West Bengal. Moreover, the countries Bangladesh and Bhutan share international borders with the state. The hilly areas of the State have good hydro potential as small streams can be harnessed for decentralized power generation through small hydro development. These hilly areas mainly fall within the two hill districts - Karbi Anglong and North Cachar Hills. The exact estimation of total potential of small hydropower development in the State is yet to be made. In Assam mainly two agencies, the Assam Power Generation Corporation Limited (APGCL), a corporation of Assam State Electricity Board (ASEB), and the Assam Energy Development Agency (AEDA), are involved in survey, preliminary investigation, preparation of Detailed Project Reports, and execution of small hydro projects. The APGCL has so far identified 93 small hydro sites with a total potential of 159.37 MW, 1 of which has already been commissioned but has been inoperative since 1993 while 4 others are under various stages of execution details of which are given in Table I [3] and Table II [3] . The AEDA has so far identified 6 small hydro sites having a total potential of 2.21 MW, 2 of which have already been commissioned while DPRs have been prepared for 3 sites. AEDA had also made a hydrological study of a site at Bichitur in Karbi Anglong District where a potential of generation of about 1.8 MW has been identified. The details and status of the small hydro projects identified by AEDA are given in Table III [3] and Table IV [3] .