IWP&DC provides brief details of the ten largest hydropower projects currently under development in India
Subansiri (lower) – 2000MW
Subansiri Lower project is the biggest hydroelectric project undertaken in India so far and is a run of river scheme on Subansiri River. The Project is located near North Lakhimpur on the border of Assam and Aruncachal Pradesh. Features of the project include: 116m high concrete gravity dam, 9.5m dia headrace tunnel, surge tunnels and a surface powerhouse. alstom was awarded the contract to 8x250MW vertical shaft Francis turbines, the digital governing system, butterfly valves, 116kV vertical generators and static excitation systems for all components. The plant is due to come into operation in 2012.
Teesta III – 1200MW
In December 2007 Andritiz Hydro was awarded a contract for the complete electromechanical equipment for six vertical Pelton turbines at the Teesta III hydropower project. Teesta Urja Ltd is developing the 1200MW scheme in North Sikkim. The turbines are due to be installed by August 2011 with annual generation estimated at 5269GWh. The project comprises: a 60m high CFRD; two 16 x 21.2 x 285m desilting chambers; a 14km headrace tunnel; 136m high surge shaft 20m in diameter; two 1135m long pressure shafts 4m in diameter; and an underground power station.
Karcham Wangtoo – 1000MW
Despite bad monsoon weather causing disruption to construction progress, the first unit of the 1000MW Karcham Wangtoo hydropower project is due for commissioning six months ahead of schedule. Suren Jain, managing director of Jaiprakash Power Ventures, said that the first unit will start producing 250MW of power as IWP&DC went to press in March 2011, with the other three ready for operation by June. Located on the Sutlej river in Himachal Pradesh, construction at the project started in 2005. As a run-of-river scheme it will utilise the available head between the tailwaters of Baspa II and the head water of Nathpa-Jhakri projects. A consortium of voith-siemens and va-tech Hydro (now andritz Hydro) supplied 4x250MW Francis units which have been made erosion resistant, as during the rainy season the sand and silt content of the river water is extremely high.
Siyom – 1000MW
The Siyom hydroelectric project is being developed by Reliance Power subsidiary Siyom Hydro Power on the Siyom River in the West Siang district of Arunachal Pradesh. Scheduled for completion in 2015, the project is being developed as a run-of-river scheme. The civil works package for the project is expected to be awarded in June this year.
Tehri pumped storage – 1000MW
Being developed by Tehri Hydro Development Corporation in Uttarakhand, the Tehri pumped storage project is part of the 2400MW Tehri hydro complex. Due for completion in 2013, the project will include four reversible pump turbine units of 250MW capacity each. The Tehri Dam reservoir will function as the upper reservoir for the project, with the Koteshwar reservoir acting as the lower balancing reservoir. Other features of the project include headrace tunnels, penstocks and and underground machine hall.
Parbati II – 800MW
Stage II of the Parbati hydroelectric project is due for completion in March 2013. The 800MW run-of-river scheme will harness the hydro potential of the lower reaches of the river Parbati in Himachal Pradesh. A gross head of 862m between the villages of Pulga in the Parbati valley and Suind in Sainj valley will be utilised to generate the power. The main project features are: an 85m high concrete gravity dam; 130m high, 17m diameter orifice type surge shaft; 6m diameter, 31.52km long headrace tunnel; two pressure shafts (each 1546m long and 3.5m in diameter); and a surface power house containing 4x200MW Pelton turbine generating units.
Tato II – 700MW
Located in West Siang District of Arunachal Pradesh, India, the Tato II project will harness the waters of the Siyom River. Being developed by Reliance Power Ltd, the project is due for completion in 2014. Tato II will feature four 175MW generating units (vertical Francis), each operating under a rated net head of 168m. The units will be housed in an underground powerhouse. Other project features include two 600m long diversion tunnels, two 4km long headrace tunnels and a concrete gravity dam.
Kameng – 600MW
The Kameng hydroelectric project is being developed by the North Eastern Electric Power Company (NEEPCO). The project, which is expected to be complete in 2013, will be a run-of-river scheme situated in the West Kameng District of Arunachal Pradesh. The project will utilise flows from Bichom and Tenga Rivers (both tributaries of the River Kameng) over a gross head of 536m (design head 504m) available in a ‘U’ bend of the river downstream of the confluence of the River Bichom with Kameng. The project will feature two concrete gravity dams – the 69m high Bichom Dam and the 24.5m high Tenga Dam. It will include 4x150MW Vertical Francis turbines, housed in a surface powerhouse. Other project features include a 70m high surge shaft, and a 400/132 kV switchyard.
Loharinag Pala – 600MW
India’s National Thermal Power Corporation’s (NTPC) 600MW Loharinag Pala project, located on the Bhagirathi river at the headstream of the Ganges in Uttarakhand, began construction in 2006 but was stopped three years later following protests. Although partial resumption of work was allowed in view of the huge investment NTPC had already made on the project, in August 2010 the government decided to scrap the project citing religious and environmental concerns. NTPC chairman and managing director Arup Roy Choudhury says that this is a setback but the company is still trying to revive the project. Choudhury has expressed concerns about the substantial amount of work which has already been completed on the project. There is concern that leaving the project after tunnels and shafts have been dug could pose a safety risk.
Parbati III – 520MW
The 520 MW stage III of the Parbatti project is located in Kullu district in Himachal Pradesh. The run-of-river scheme envisages diverting the tailrace releases of the stage II powerhouse as well as inflows from the river Sainj through a 7.8km long headrace tunnel. A design discharge of 181m3/sec and a gross head of 356m will be utilised by the 4x130MW vertical Francis turbine and generating units in the underground power house. Completion of this stage of the project is scheduled for June 2011.