AD Hydro Power Ltd. has constructed 192 MW Allain Duhangan Hydroelectric Project on Allain & Duhangan streams, tributaries of River Beas, in the Kullu district of Himachal Pradesh.

Commercial operation of the plant with full installed capacity commenced from 18th September, 2010 by utilizing Allain Stream water in the first phase and the project became fully operational in February, 2012 after completion of the second phase i.e. Duhangan side trench weir and HRT.

The Project has been envisaged with the purpose of exploiting the power potential in the lower extremities of Allain & Duhangan streams, (tributaries of the Beas River). The project is located near Village Prini of Manali in District Kullu, Himachal Pradesh (India) located at a distance of 60 Km from Bhuntar Airport and is 500 Km from Delhi by road.

The project is a “Run of River” (ROR) hydroelectric power generation plant with an installed generation capacity of 192 MW and an annual design energy of 699.78 million kilowatt hours of electrical energy in 90% dependable year.

The project components consist of a gated barrage with 2 nos. Spillway Gates and 2 nos. Under sluice Gates across Allain stream, 4 nos. head regulator gates, 4 nos. De-silting chambers on Allain side and a trench weir, 1 no. head regulator gate, an inlet tunnel and an underground De-silting chamber on the Duhangan stream. An Intermediate Storage Reservoir of 225,000 cubic meter storage capacity is provided. Two tunnels, of length 4025m and 4340m from Allain and Duhangan streams respectively culminate before the Penstock Protection Valve from where a vertically inclined Pressure shaft of 1524 m length and diameter varying from 3000 to 2400mm, steel lined, carries the design discharge of 26.8 cumecs with maximum gross head of 876.0 m and net head of 858.0 m conveys the water to generate 192 MW (2x96MW) of power in an underground Power House having two, 5-jet Pelton turbines. 

The power house includes two main caverns on the left bank of Allain stream, the machine hall of 68m long x 34m high x 15.3 m wide housing the two Pelton turbine units, auxiliary equipment, service bay control room etc. and transformer cavern 68m long x 12.5m high x 12.5m wide housing seven nos. single phase transformers. 

The generation voltage is 11 kV which is stepped up to 220 kV by the 2 nos. single phase banks of Generator-Transformers each of 135 MVA capacity.

The Project also includes a dedicated 176.5 km 220 kV double circuit transmission line, through which power is evacuated from the project site to the Power Grid Corporation of India 400/220 kV Substation, Nalagarh.

The plant is designed to operate as a base load plant during the summer and rainy seasons and as a peaking plant in the winter/non-monsoon months.

AD Hydro power Limited is a Merchant Power plant and as such there is no Power Purchase Agreement (PPA) executed with the State Govt. or any other agency. The project sells its power in open market on competitive bidding basis under bilateral arrangements and also through IEX.