Pakistan and the USA have signed, on June 7, an agreement under which the USA will provide, through the USAID (United States Agency for International Development), $445.6 million for supporting climate-resilient economic growth covering clean energy, environment, health, education and governance in Pakistan. To be implemented during the 5-year period, the program will focus on helping realise the potential of renewable energy’s share optimally to reduce current heavy reliance on fossil fuels, and promoting efficiency measures towards a low-carbon economy in the power sector. The objective is also in line with Pakistan’s energy policy in vogue that plans fast transition from fossil-fuel based power generation to renewable energy. For this purpose, an amount of $179.2 million has been allocated out of total funding of $445.6 million.
Pakistan and the USA have signed, on June 7, an agreement under which the USA will provide, through the USAID (United States Agency for International Development), $445.6 million for supporting climate-resilient economic growth covering clean energy, environment, health, education and governance in Pakistan. To be implemented during the 5-year period, the program will focus on helping realise the potential of renewable energy’s share optimally to reduce current heavy reliance on fossil fuels, and promoting efficiency measures towards a low-carbon economy in the power sector. The objective is also in line with Pakistan’s energy policy in vogue that plans fast transition from fossil-fuel based power generation to renewable energy. For this purpose, an amount of $179.2 million has been allocated out of total funding of $445.6 million.
The USAID has been collaborating with Pakistan since long for improving and expanding the power system, in particular, the hydroelectric power generation, which is green, clean and affordable renewable energy. The most significant element of this cooperation has been the rehabilitation and modernisation of old and outmoded mega hydropower projects like Mangla and Tarbela. In the recent past the USAID had extended financial and technical assistance for the repair, refurbishment, and modernisation of four generating units of old Tarbela power plant which consists of ten units (units 1-10), resulting in higher performance and increasing their lifetime, besides other salutary benefits.
Tarbela hydropower is the largest electricity generation facility in the country, with an installed capacity of 4,888-MW which will increase to cumulative 6,298-MW total peak generation capacity on completion of its under-construction 5th extension project, scheduled for commercial operations in 2025-26. Currently, Tarbela power plant has over 45 percent share in total hydropower installed capacity and 13 percent share in total energy mix at national grid, supplying electricity to tens of millions of consumers. Termed as an iconic multipurpose project for the contributions it has been making towards achieving economic stability and social development for almost five decades, globally it is today the 5th largest structure by volume, the 2nd largest reservoir in terms of reservoir capacity, and the 8th largest dam.
The project construction was carried out in different phases. Four generating units (units 1-4), each of 175-MW capacity, were commissioned in 1976-77 in the first phase, and another six units (units 5-10), each of 175-MW capacity, were installed during 1982-1985. Four larger–capacity units 11-14, each of 432-MW, were added to the system in 1992-93 under the 3rd expansion project. All the ten generating units (units 1-10) are ageing and obsolescing. Refurbishment of units 1-4, which were operating much below their rated capacity as the main plant machinery had outlived its useful life, was undertaken in 2011 under the USAID grant.
Critical components of generators, such as windings, excitation systems and surface air-coolers were replaced employing latest technology, along digital governors, SCADA system and essential spares like seals and guides for relief and by-pass valves on turbines, and drainage & dewatering pumps, compressors etc. This helped restore the original power generating capacity of the four units thereby adding total 216-MW generating capacity to the then de-rated capacity, and extending units’ life by another 15-20 years. The USAID has also financed refurbishment and modernisation of units 5-8, which has been done partially. While regular maintenance of these units is being carried out on an annual basis, these units require major overhauling, refurbishment and modernisation of electromechanical equipment. Thus, static exciters of units 5-8 were upgraded, governors were replaced and SCADA system installed, besides replacement of essential parts.
Recent advancements in hydropower technologies not only aim at improving turbine efficiency and reducing noise and vibration that can cause damage to runner blades, there is also a target on improving overall performance of power plants for enhancing output and mitigating environmental issues, ensuring reliability and sustainability of power generation. A turbine runner of high-performance modified design based on latest X-Blade technology was procured which is currently being installed and commissioned under foreign experts’ supervision, replacing the old turbine runner of unit 5. Historically, this is for the first time that any runner of the size of 175-MW is being replaced by WAPDA since its commissioning which is indeed a complex and arduous job. All these activities have been financed under the $41 million USAID grant provided to WAPDA in two phases. Turbine runners of units 6-8 have also worn out due to ageing and need to be replaced within a few years. Likewise, generator windings of units 5-8 have outlived their lifetime and risk long-term shutdown of any unit any time. For the reason of safe and reliable operation of these units, which are in operation since 1982, the windings are required to be replaced progressively.
This situation underscores the need for an immediate and comprehensive program to upgrade the depreciated and obsolete machinery for regaining the original installed capacity, increasing plant efficiency, alleviating outages, and, above all, overcoming shortage of electricity at national level. It is imperative that revitalisation of Tarbela units 5-8 be prioritised, in the first phase, to enhance reliability and sustainability at the powerhouse by about 20 years. The objective can be achieved by utilising the recently committed American funding of $179.2 million allocated for the objective of enhancing clean renewable energy and promoting efficiency in the power sector, of which $10.07 million is the USAID grant. This is the most opportune time to avail these funds in this direction in the wake of current import restrictions due to lack of cash foreign exchange with the government, which is hampering the on-going refurbishment and upgrading program of the old Tarbela powerhouse.
The writer is retired Chairman of the State Engineering Corporation
