Alaknanda Hydro Power Company Limited (AHPCL)
The Alaknanda hydroelectric project is a 330MW hydropower generating station developed on the Alaknanda River in Uttarakhand, India. Also known as Shrinagar hydroelectric project, the power station was developed by Alaknanda Hydro Power Company (AHPCL).
AHPCL, a GVK group company, implemented the greenfield project pursuant to an implementation agreement signed in February 2006 with the Uttar Pradesh and Uttarakhand governments.
Built at a cost of Rs45.73bn ($728m), the project is expected to generate approximately 1,514GWh of energy a year, including 1,397GWh of primary energy and 117GWh of secondary energy.
The project was officially inaugurated in March 2014 and the first unit was successfully synchronised with the Northern Grid in April 2015. All four units were commissioned by June 2015.
The project was initially proposed to commence operations in 2013 but was delayed due to an unprecedented natural calamity that occurred in June 2013. The incessant rains and resultant floods breached the dyke in front of the powerhouse with a huge deposit of silt, which was cleaned.
Shrinagar HEP power generation will reduce greenhouse gas emissions and enable the state and the country to achieve the goal of low carbon growth.
Alaknanda hydroelectric power project details
The Alaknanda hydroelectric power station is located near Gaurshali village, 10km from Shrinagar district of Uttarakhand.
The run-of-river hydroelectric project is expected to reduce the northern grid’s dependence on fossil fuel to produce power. It included the construction of a 98m-tall concrete gravity diversion dam, a headrace tunnel, six intake tunnels, a desilting basin, a powerhouse, a tailrace channel, and a switchyard.
The project features two 1,100m-long headrace tunnels constructed to convey water to the powerhouse. The desilting basin is located at the end of the RCC trough section. The intake structures are located at the end of forebay, which comprises four penstocks of diameter 5.6m and length of 114m.
The powerhouse is located on the surface and consists of four 82.5MW Francis turbine units with a net head of 66m and design discharge of 560m³/s. The turbine generator is a vertical shaft synchronous machine with a rated continuous output of 97.06MVA and a rated speed of 166.6rpm. The turbines are controlled by electro-hydraulic modern type governors.
The switchyard consists of four 400kV outgoing transmission line bays.
Power offtake and transmission from Alaknanda HEP
AHPCL signed a 30-year power purchase agreement (PPA) with Uttar Pradesh Power Corporation in June 2006 to sell approximately 88% of the power generated by the plant. The PPA was signed in June 2006. Uttarakhand state will receive the remaining 12% power free of charge.
The 13.8kV power generated by the turbo generator is increased to 400kV by a transformer. It is evacuated and connected to the Shrinagar substation through an under-construction 13km-long 400kV double circuit transmission line.
Financing of Alaknanda power project
The project achieved financial closure in August 2007. It was initially estimated to cost Rs20.69bn ($332m) but revised to Rs36.75bn ($590m) in 2011 and ultimately cost Rs45.73bn ($728m) due to the delays.
Contractors involved with GVK’s hydroelectric project
BHEL was awarded the contract for the supply, erection, and commissioning of four turbine-generator units, auxiliaries, and electro-mechanical works for the project.
SMEC conducted detailed engineering services, including the preparation of tender documents for the project.
Ocimum Constructions was awarded the contract for conducting concrete works required for the civil works of the 330MW hydroelectric power project.