Jaypee’s Karcham Wangtoo Hydroelectric Project in north-west India is all set for commissioning and beginning to generate power, as Ruari McCallion learns from Mr D P Goyal.
Hydroelectric power has a dualistic reputation. On the one hand, it generates electricity without emitting tonnes of carbon dioxide (CO2) or other greenhouse gases into the atmosphere. The other side of the coin is that hydroelectric power dams have a history of drowning hundreds or thousands of square kilometres of land under millions of tonnes of water, which is then used to turn the generator turbines. But the recent emergence of ‘run-of-the-river’ hydropower projects presents a different story. They don’t require huge dams—essentially enough to store sufficient water to ensure peak demand coverage—and so they don’t drown the landscape. Run-of-the-river hydropower projects tend to be associated with smaller-scale storage requirements, perhaps supplying the needs of a local community, but that does not always have to be the case.
The Indian state of Himachal Pradesh is located in the north-west of the country in the south-west Himalayas. It is a mountainous region, with steep valleys and gorges cutting into the Himalaya ranges. The landscape is ideal for run-of-the-river hydropower—and it doesn’t have to be small-scale. The Karcham Wangtoo Hydroelectric Power Project is being constructed on the Satluj river in the Kinnaur district in the west of the state, between the villages of Karcham and Wangtoo. The river is fed mostly by the snow melt in the upper areas and by the monsoon in the lower areas, and is a vital supply to the region’s population—a consideration that received high priority in the design of the project.
“We have to divert just under half of the flow into a tunnel, which is discharged back into the river about 17 kilometres downstream,” says Mr D P Goyal, managing director of Jaypee Karcham Hydro Corporation Limited. “Outside the monsoon season, the water is held behind the Karcham Dam on a daily basis in order to enable us to meet peak demand, which generally occurs between 6am and 9am, and from 6pm to 10pm. The total area of land that will be submerged behind the dam amounts to only 62.61 hectares.”
The first generating unit is scheduled to be commissioned in August 2011 and all four units by mid-November 2011. With the acceleration measures adopted under the inspiration and guidance of Mr. Jai Prakash Gaur, the founder chairman of the Jaypee Group, the project proponent is making all efforts to bring forward the commissioning by three to four months. When completed, the Karcham Wangtoo hydroelectric power station will produce 1,000 MW of electricity—so this is larger than a community-level run-of-the-river project. In fact, when it received the go-ahead, it was the largest such project in the private sector in India. The dam itself rises 88 metres from its deepest foundation level and is 182 metres long at the top, with four sluice spillway bays. The project has a head race tunnel 10.48 metres in diameter and 16.92 kilometres in length; four pressure shafts; an underground powerhouse with four 250 MW Francis turbines; a transformer hall; and a tail race tunnel 1.3 kilometres long and 10.48 metres in diameter.
“The project was approved considering the power shortages in the power grid in north-west India,” Goyal explains. “Cuts and power outages occur often. The state of Himachal Pradesh has surplus power for most of the year and sells it to neighbouring states, including Punjab, Uttar Pradesh and Rajastan.” However, it is worth bearing in mind that Karcham Wangtoo is well into the Himalaya ranges—it is located at over 1,800 metres (6,000 feet) elevation and surrounded by mountains. Besides the hydropower station, the means to transmit the power has to be constructed. “We are investing in transmission infrastructure and building 217 kilometres of 400 Kv double-circuit lines from the power station to the grid point through Jaypee Powergrid Company Limited.”
Besides the location being remote, the main challenges have been geological. “We encountered very high temperatures in the rocks—up to 98 degrees Celsius—when we were excavating the tunnel,” Goyal says. “We had to deal with highly fractured rocks, water ingress and soft strata also.” Jaypee used Atlas Copco tunnel drilling equipment, equipped with a special forepoling boom attachment, to help it complete the task before time.
Apart from the physical challenges, environmental issues required extensive consultation and planning before clearances were issued by the government agencies. “Commencement of construction got delayed by about 23 months, from January 2004 to November 2005, while we waited for environmental and forestry approval,” says Goyal. Jaypee is optimising the construction period by deploying additional equipment and by recruiting additional staff—as at April 2010, the project involved 14,369 people, including contractor personnel. “When the project is running, around 750 people will be employed, including security staff.” And the challenges will not end once the ‘on’ buttons are pressed in 2011.
“We get lots of silt in the river during the monsoon,” Goyal continues. “Clearly, that has to be kept out of the turbines and pretty much all of the hydromechanical parts, which would be damaged by it. We have constructed the largest underground de-silting basin to exclude silt particles down to a size of 0.2 mm and we also decided to invest in full tungsten-carbide coatings for the runners. If one runner gets damaged, which is quite possible, it will take about 18 days to replace it, so we have built in 100 per cent redundancy—we have a full set of spare runners.”
The entry of the private sector into power generation in India is relatively recent. Jaypee Karcham Hydro Corporation was set up seven years ago as the special purpose build-own-operate vehicle for the construction and operation of the Karcham Wangtoo Hydroelectric Project. The total cost of the project will be about US$1.5 billion by the time it is completed. It is unlikely to be the last such project in Himachal Pradesh as untapped potential for hydroelectric power in the state, especially run-of-the-river schemes, remains very large. Jaypee Group already owns two other hydropower plants under operation; namely the 300 MW Baspa-II hydroelectric project, also in the district of Kinnaur in Himachal Pradesh, and the 400 MW Vishnu Prayag hydroelectric project in Uttaranchal State. It undoubtedly has the experience and expertise to bring such opportunities to fruition.
The Jaypee Group also plans to take up execution of the 2,700 MW Lower Siang hydroelectric project and the 500 MW Hirong hydroelectric project in Arunachal Pradesh State; as well as the 450 MW Kynshi Stage II hydroelectric project and 270 MW Umngot hydroelectric project in Meghalaya State in north-east India.