THE financial close of three hydroelectric power projects has been achieved recently with the support of friendly countries.

These projects are Tarbela 4th Extension of 1,410 MW, Golen Gol of 106 MW, and Keyal Khwar of 122 MW capacity.

The construction of the Golen Gol project is in progress under the Saudi Development Fund, while its re-tender for electrical and mechanical works is scheduled for opening in August, financing for which has been provided by Kuwait Development Fund.

Bids for civil works of the Tarbela Extension project, which is being financed by the World Bank, are currently under evaluation, and bids for electro-mechanical works will shortly be received.

Likewise, the German financing agency KfW has already signed an agreement for implementation of the Keyal Khwar project.

On the other hand, the Water and Power Development Authority (Wapda) has set as a strategic priority to implement rehabilitation and modernisation schemes of existing old hydropower stations. Major repair, overhaul and rehabilitation of Tarbela and Warsak power stations has recently been undertaken, while refurbishment and modernisation of Mangla power station is being implemented under USAID financing.

Currently, Wapda operates 18 hydropower stations — large, medium and small — with a cumulative installed capacity of about 6,880 MW, and generates more than 33,000 GwH of net electrical energy.

Small hydropower stations connected to the national grid are Rasul (22 MW), Dargai (20 MW), Nandipur (13.8 MW), Shadiwal (13.5 MW), Chichoki (13.2 MW), Kurram Garhi (4 MW) and Renala (1.1 MW). Jabban, also known as Malakand-I, of 19.6 MW capacity, was de-commissioned in 2006 as a result of a fire accident. Three units of the Jabban power station were commissioned in July 1938, and another two units were added in October 1952. Gomal Zam (17 MW) has recently been added to Wapda’s power generation system.

While their share in the total installed hydropower capacity at the national level is less than two per cent, these small hydropower stations contribute significantly towards bridging the gap of electricity demand and supply, thus reducing load-shedding, particularly during peak hours.

These small power stations generated 271,256,505 units (kWh) of electricity in 2012, despite their being obsolesce and operating much below their rated capacity.

The economic lifetime of a hydropower plant is between 40 to 80 years, depending on operating conditions of the installed plant machinery. However, most of these power stations were commissioned more than half a century ago; therefore having outlived their designed useful life since long, and resulting in loss of power generation.

Wapda therefore plans to carry out major renovation, refurbishing, upgrading and modernisation of some of these small hydropower plants, hoping to harness optimal hydropower potential at the sites.

The Jabban hydropower station, now up-rated to 22 MW installed capacity, has recently gone into trial runs, and is expected to commence power generation on a commercial basis within a few months to generate 122 GwH annually. The project, costing $38 million, is financed partially by the French Development Agency, and its construction began in February 2010. Complete new power plant machinery, including four modern turbines of 5.5 MW each, has been installed, utilising the existing infrastructure of transmission and dispersal of power.

Renala hydropower — the oldest power station in the country — was commissioned in March 1925. Located on Lower Bari Doab Canal, in Okara district, it has five turbo-generators of 0.22 MW each, and all its units have been in operation since then. After rehabilitation and refurbishment, there is a potential to enhance the power station’s capacity up to four MW, utilising full available water discharge.

On completion, the powerhouse will generate 25.6 GwH annually, almost four times its existing power generation. The up-rated project will also involve remodeling of existing power channel off-taking from the canal, and the construction of new spillways. The project’s feasibility has been finalised by Wapda, whereas PC-1 approval is pending for want of financing arrangement. The total cost of the project is estimated at $14.35 million.

The Shadiwal hydropower station, located near Gujrat, is currently generating four MW, compared to its installed capacity of 13.5 MW (four units of 6.75 MW each). Commissioned in January 1961, it has the potential of increasing its total capacity to 27 MW, subject to availability of required quantum of water that is possible through rehabilitation of the Upper Jhelum Canal.

The Dargai (Malakand-II) power station, located on Swat River, has four units of five MW each, and was commissioned in December 1952. Likewise, the Kurram Garhi power station, which is located on Kuchkot Canal in Khyber Pakhtunkhwa, was constructed in 1958. Rasul powerhouse, with two units of 11 MW each, was installed on Chenab River in July 1952.

Nandipur hydropower (consisting of three units of 4.6 MW each) is located on Upper Jhelum Canal near Gujranwala, and was commissioned in March 1963. Similarly, Chichoki Hydel (three units of 4.4 MW) has been operating since August 1959, and generating about 23 GwH annually. It is located on Upper Jhelum Canal, near Shaikhupura.

Meanwhile, the reliability of the existing electro-mechanical equipment of these powerhouses has deteriorated, and efficiency reduced from designed values and parameters of the installed equipment. However, Wapda has not planned to refurbish and upgrade any of these six power stations, which would have ensured reliable operations and restoring them to their original power generating capacity.

To achieve high availability and reliability of operations of these old power stations, it is essential to undertake major overhaul, rehabilitation, upgrading and replacement of existing hydro-mechanical and electrical equipment. This will also result in enhancing capacity, in a few cases, and increasing profitability and long-term value of these hydropower stations.

Upgrading these old small hydropower stations will not only ensure power substitution, but will also add to the installed power generation capacity. After upgrading and refurbishment, all the powerhouses will be operable for another 35-40 years.

The writer is a former chairman of the State Engineering Corporation.