To assess power plants’ positive impacts on national grid, Institute of International Relations and Media Research (IIRMR) has conducted a research study and found that Pakistan has underlying weakness in the electricity infrastructure, grid system and transmission line in the length and breadth of country. “It carries installed power capacity to meet demand, but it struggles to revamp aging power system. Generators are too far from the load centres and transmission lines are too long and insufficient,” it revealed.
Given the situation, it said that Sahiwal Coal Fired Powered Plant (SCFPP), early harvest energy project of CPEC, has been playing an anchoring role in boosting up Pakistan National Grid System.
Study divulged that In 2017, when power system stability was in jeopardy, the Sahiwal Coal Fired Power Plant (SCFPP) was integrated into the national grid via a sophisticated in-and-out configuration at Qadirabad, Sahiwal District in Punjab, house of more than 100 million people. “Before this, a direct 500 kV transmission line connected Yousafwala in Sahiwal to Lahore, establishing a unidirectional power flow between the two cities.
The introduction of the SCFPP significantly altered this dynamic by facilitating bi-directional power flow, which optimized the efficiency of energy distribution,” the study mentioned.
“Strategically situated approximately equidistant from Lahore, Multan, and Faisalabad, Sahiwal has emerged as a crucial power hub. Historically, the lack of substantial generating capacity in this region posed significant stability challenges for the national grid. The commissioning of the SCFPP has since enhanced the stability and reliability of electrical parameters within the grid,” the IIRMR study added.
The SCFPP plays a pivotal role in stabilizing frequency around this central load area and addressing the demand for reactive power, it said and further stated that in summer months, the plant provides essential reactive power to support the grid’s inductive loads, while in winter, its capacity to absorb reactive power helps stabilize system voltage.
“The Lahore Electric Supply Company (LESCO), which represents about 20% of Pakistan’s peak demand at approximately 4500 MW, had previously experienced notable voltage fluctuations, particularly during peak periods. Despite the installation of static VAR compensators at various grid stations, voltage stability remained problematic. The addition of the 1320 MW capacity from the SCFPP has substantially ameliorated the voltage profile in this region,” it said.
“The National Transmission and Dispatch Company Limited (NTDCL) also lauded the SCFPP for its multiple contributions to the national grid system. These include enhancements in power supply stability within Sahiwal and its surrounding grid networks, improved grid stability and reliability, and better voltage regulation in the Multan Electric Power Company (MEPCO) and LESCO areas,” the study detailed.
Before the Sahiwal power plant’s integration, a study said that the 500 kV Yousafwala substation was fed through a network of transmission lines from other substations, rather than directly from generating units. This setup complicated load management and stability. “An official at 500 kV Yousafwala Grid Station, observed that “before the CFPP Sahiwal was added, the 500 kV auto transformer banks at Yousafwala were underutilized relative to the load demands of the DISCOs (Distribution Companies): MEPCO, LESCO, and FESCO (Faisalabad Electric Supply Company),” it revealed.
Consequently, IIRMR President Yasir Habib Khan said that maintaining system stability often necessitated load shedding at the DISCO level, despite the implementation of under-frequency schemes on 132 kV transmission lines at the NTDC level. “The SCFPP’s addition has not only optimized the use of existing auto transformer banks at Yousafwala but also led to the installation of an additional 600 MVA auto-transformer bank, thereby reducing load shedding across DISCOs,” the study said.
“Another significant advantage of the Sahiwal CFPP is its impact on the voltage profile in surrounding DISCOs, ensuring that most inductive loads at the consumer end receive sufficient reactive power. An engineer at MEPCO noted that “the establishment of the Coal Fired Power Plant in Sahiwal markedly improved voltage levels at the 500 kV Yousafwala Grid Station. Previously, the grid was fed by two 500 kV single-circuit lines from Sheikhupura and Multan, covering distances of 195 km and 180 km, respectively.
These long transmission lines caused significant line losses and voltage drops. The addition of a 1320 MW power source at Sahiwal addressed these issues. Although the initial commissioning of this large power source led to the overloading of the Yousafwala Grid, where existing autotransformers were operating at about 50% capacity, the CFPP enabled these transformers to operate at full capacity and necessitated the installation of an additional 600 MVA 500/220 kV auto transformer bank. This has significantly enhanced the voltage profile in the division,” the IIRMR study clarified.
“The National Power Control Centre (NPCC) in Islamabad initially worried that frequent tripping of a major generating unit could lead to more frequent system blackouts. However, the SCFPP has demonstrated its reliability as a base-load plant over the past seven years. Its consistent power output has allowed the NPCC to manage electrical parameters—such as frequency, reactive power, and voltage—more effectively.
The reliable and stable supply from the Sahiwal power plant has significantly aided the NPCC in effectively countering blackouts during this period. NPCC also remarked that “Since its inception, the Huaneng Shandong Ruyi SCFPP has established new benchmarks in reliability, stability, and safety within the power sector, ensuring the provision of safe & stable electricity to the people of Pakistan. Long Live Pak-China Friendship,” the study concluded.
