Brownouts and blackouts are critical issues affecting the stability and reliability of power supply systems in Pakistan. A brownout is a partial, temporary reduction in power availability, often indicated by a voltage drop in the system. This phenomenon usually occurs when the power system is under stress, possibly due to high demand or infrastructural limitations. In contrast, a blackout is a more severe condition, characterized by a complete loss of power in a specific area, typically caused by overloads, system failures, or significant malfunctions in the power grid. Both brownouts and blackouts can have a profound impact on the entire economy , including businesses and healthcare, thus emphasizing the need for a robust and reliable power infrastructure.
Brownouts and blackouts are critical issues affecting the stability and reliability of power supply systems in Pakistan. A brownout is a partial, temporary reduction in power availability, often indicated by a voltage drop in the system. This phenomenon usually occurs when the power system is under stress, possibly due to high demand or infrastructural limitations. In contrast, a blackout is a more severe condition, characterized by a complete loss of power in a specific area, typically caused by overloads, system failures, or significant malfunctions in the power grid. Both brownouts and blackouts can have a profound impact on the entire economy , including businesses and healthcare, thus emphasizing the need for a robust and reliable power infrastructure.
In this article, we investigate the challenges of Pakistan's power sector, focusing particularly on the risk of blackout winters. We examine the effects of seasonal changes in power generation, such as the decline in hydroelectric power and gas supply limitations in winter. We explore the phenomena of brownouts and blackouts, their causes, and their broader implications for power infrastructure. We delve into operational challenges, such as maintenance outages and the management of frequency reserves, as well as issues related to industrial demands and grid connections. Our focus extends to the capacity trap in generation, complexities in power system management, investment deficits, policy dynamics, and technical constraints. Ultimately, the need for holistic solutions to enhance grid reliability and prevent blackout winters encompasses all aspects of power sector vulnerabilities.
Pakistan’s power generation, dominated by baseload capacities like nuclear, coal, and CCGTs, faces significant challenges in meeting the country’s fluctuating demand. Reliance on imported fuels (i.e., coal and LNG) coupled with financial constraints faced by the economy adds considerably to the power system’s vulnerability and leads to high capacity payments due to suboptimal utilization.
Hydroelectric power, a major component of Pakistan’s energy mix, is heavily influenced by seasonal variations that can be attributed to the country’s dependence on water flow for agriculture and the inherent nature of hydrological cycles that are vulnerable to weather extremes and shifting patterns. As a result, hydroelectric generation drops significantly during winter months, causing a sizable reduction in overall power generation capacity. For instance, during FY22, Pakistan’s hydroelectric generation peaked at 7,561MW in August while the minimum output was recorded at 697 MW in January, compared to the total installed hydroelectric capacity of 9,477 MW.
Similarly, reduced gas supply during the winter also impacts generation from Gas Power Plants due to load profiling of Residential Piped Natural Gas Consumers, further limiting power production.
With an industrial base load of around 8 GW at present, large seasonal and intra-day variations in grid electricity makes surplus capacity very expensive. On August 21st, 2023, for instance, the National Transmission and Dispatch Company (NTDC) supplied 25.5 GW of electricity at midnight, with approximately 17.5 GW catering to the seasonal demand for ventilation and air conditioning, i.e., cooling loads. Notably, the installed capacity of 22 GW in FY14 was sufficient to meet industrial demand of 7-8 GW. The subsequent escalation in electricity demand and prices can therefore be attributed to higher consumption in non-productive sectors, particularly for cooling and ventilation.
It is important to note that hydropower plants are modeled based on their characteristic monthly minimum and maximum available capacities, along with their average monthly generation. With more than a dozen new hydropower projects being installed, there is a clear indication that the future of energy in Pakistan hinges on adapting to seasonal patterns and integrating various forms of renewable energy to ensure a stable and reliable supply of electricity.
Moreover, operational constraints require nuclear and RLNG plants to run at a minimum capacity of 70%, and coal plants at 50%, leading to inefficiencies during low-demand period. Consequently, the current generation mix, despite its diversity, struggles to match the variable demand and seasonal hydropower availability, resulting in underutilization of large fossil fuel plants due to financial and grid optimization limitations.
Operational Challenges: Frequency Management and Grid Stability
Investment in transmission and distribution infrastructure, focused on short-term fixes rather than long-term solutions such as grid optimization and flexible generation, has not kept pace with the expansion of generation capacity, leading to overburdened systems and supply bottlenecks. This, coupled with insufficient funding exacerbated by mounting circular debt, has caused serious transmission issues and network bottlenecks, with many sections operating above capacity. Additionally, managing frequency reserves, crucial for stability, especially during reduced generation, is challenging due to insufficient operating reserves, limiting backup power during demand spikes or generation drops.
The system has a reduced number of operational generating units, which leads to low inertia. Inertia is important for maintaining grid stability and the ability to recover from disturbances. A lack of sufficient operating units makes the system more vulnerable to outages. Additionally, maintaining large spinning reserves to align with the biggest thermal generation units introduces additional operational and financial complexities.
Under severe outage events, all power plants must provide adequate frequency support. This support becomes crucial for the low-inertia system under very low load demands, such as during winter months. Allegedly, power plants, especially IPPs, do not provide sufficient frequency support, leading to the system's inability to restore its frequency and resulting in blackouts.
Furthermore, fog and smog can cause short circuits in transmission and distribution networks due to their moisture-laden conductive particles, leading to network tripping, brownouts, and operational disruptions that affect power supply stability and reliability. The reduced visibility associated with these conditions further complicates network monitoring and maintenance.
The integration of High Voltage Direct Current (HVDC) systems into the network has improved south-to-center power flow, reduced bottlenecks, and enhanced transmission reliability. However, it has also introduced additional complexity, especially during HVDC line outages. The System Operator continually faces challenges in balancing AC and DC power flows under various operating conditions to ensure grid security.
Grid Resilience Through Industrial Solar Integration
A significant portion of Large Scale Manufacturing (LSM) sectors, such as fertilizers, cement, sugar, and textiles, are not connected to the national grid, leading to an underutilization of available power generation capacity. Industries remain disconnected from the grid due to reliability and quality concerns, exacerbating the demand-supply mismatch.
In the last two years, Pakistan has witnessed the closure of numerous textile industries, looms, mills, and ice factories, with nearly half of its paper mills disappearing from the industrial landscape. This decline can largely be attributed to exorbitant electricity tariffs, which are two to three times higher than those in regional countries, placing a significant burden on these businesses. Only those businesses with higher profit margins and efficient machinery are likely to endure.
Frequent electricity supply interruptions, equipment breakdowns, and voltage instability starkly contravene the regulatory standards set forth by NEPRA in the Distribution Code, compelling industries to seek self-generated power solutions to ensure operational continuity and stability. Industries in Pakistan are confronted with the necessity of maintaining Captive Power Plants (CPPs). This necessity is driven not only by economic considerations but also by the unique energy challenges and infrastructure limitations faced by industries in Pakistan. The power system often experiences electricity shortages, grid instability, and frequent power outages, which can significantly disrupt industrial operations. To mitigate these challenges and ensure a continuous power supply, many industries in Pakistan have had to invest in Captive Power Plants (CPPs), which provide a reliable backup source of electricity, helping industries maintain production levels and avoid costly downtime. However, the financial burden of establishing and maintaining CPPs is a challenge not commonly encountered by industries in countries with more stable electrical grids.
Pakistan's generation capacity, encompassing northern hydel, southern nuclear, and coal sources, requires strategic solar plant installations at the DISCOs' 132 kV level. This should be facilitated by allowing power-wheeling through B2B contracts at a Use of System/Wheeling Charge of 1 US cent/kWh that allows for competitive end-use prices. These installations are intended to serve local loads, reducing daytime transformer load and transmission losses on both the 500/220 kV and 220/132 kV networks. To prevent evacuation constraints, it is essential to distribute solar power evenly across the nation. Such equitable deployment can reduce transmission investment by aligning with lower integration costs, optimize the grid, and limit curtailments in oversized solar PV plants. Furthermore, Pakistani industries need to invest in solar PV installations to comply with international regulations on carbon emissions like the EU's Carbon Border Adjustment Mechanism (CBAM), which is vital for maintaining competitiveness in global markets.
Inadequate Reactive Power Support and Voltage instability
In very long transmission lines, increased capacitance amplifies voltage, leading to network instability. This instability, particularly the Ferranti effect in long, lightly loaded lines, occurs when line capacitance surpasses inductive reactance, especially in grids with distant generation and load centers. Electric tripping in these networks can trigger cascading failures, causing voltage or frequency fluctuations. Such stress may result in chain reaction of failures from an initial fault, further destabilizing the system and potentially causing brownouts and blackouts. The bulk network's insufficient number of reactors fails to maintain network voltages within acceptable limits, causing significant over-voltage issues in winter. To address this, the system operator frequently has to deactivate numerous lines, thereby reducing transmission capacity reserves essential for handling contingencies,. Given the network's complex operational conditions, there is a need for dynamic reactive power support such as Static Var Compensator (SVCs), STATCOMs and Synchronous Condensers at various points, which is presently lacking.
Inadequate Grid Monitoring and Technology available for the System Operator
The system operator faces significant challenges in grid monitoring due to outdated data acquisition systems and inadequate investment in grid infrastructure modernization. This results in a lack of real-time grid information, with over 60% of the network not being monitored in real-time and relying on outdated communication methods like fax and phone.
The incomplete implementation of the SCADA system at the National Transmission and Despatch Company (NTDC) covers only about 20% of the Grid further impacts operational control and grid management. This, along with outdated operational procedures, poses challenges in handling increased load capacity and ensuring grid stability. The situation highlights the critical need for timely upgrades and modernization of Pakistan's grid infrastructure to enhance grid management and decision-making capabilities.
Policy and Market Dynamics
The rapid expansion of installed capacity in Pakistan's power sector is largely attributable to the Government's investor-friendly initiatives for Independent Power Producers (IPPs). These initiatives offer sovereign guarantees for power purchase agreements, ensuring high and guaranteed returns. This approach significantly lowered investment risks, leading to a surge in investments in power generation and a swift increase in generation capacity. However, this growth in capacity quickly surpassed both the actual electricity demand and the development of the Transmission & Distribution (T&D) network, resulting in both excess capacity on the supply-side as well as unmet demand. This situation highlights the challenges in balancing aggressive capacity expansion with demand dynamics and emphasizes the need for more demand-driven approaches in power-sector planning and development.
The energy and power sector's sensitivity to pricing dynamics highlights the need for policies that are not only market-based, transparent, and stable, but can also adapt to evolving market conditions, technological advancements and grid modernization. Such policies should encourage investments in infrastructure modernization and renewable energy sources, thus promoting environmental sustainability and energy security. Moreover, regulatory frameworks must be agile, effectively accommodating the rapid changes in energy consumption patterns and the growing demand for electricity. Generation focused policies with fixed returns that monopolize profit and socialize risk, should instead have been market based.
Emphasizing energy efficiency and demand-side management is crucial for mitigating technical and operational challenges in the energy sector. It is important to note that during winter months in Pakistan, gas consumption in residential sectors, particularly among middle- and high-income households, increases significantly. These households experience an increase of over 400% and 700%, respectively, for water and space heating requirements. To address this, a shift in space heating from gas to electricity using heat pumps--devices that transfer heat from cooler spaces to warmer spaces--is required.
In Pakistan, where domestic power demand constitutes over half of the total and shows high sensitivity to weather variations, effective Demand Side Management (DSM) is imperative. Key DSM strategies include the implementation of Advanced Metering Infrastructure for improved monitoring, Demand Response Techniques to adjust usage during peak times, and a focus on efficiency and conservation through passive solar designs and enhanced insulation.
Economic Dispatch vs Grid Reliability
The first priority of the System Operator, i.e., National Power Control Center (NPCC), is ensuring system reliability and safety to maintain voltage and frequency limits and prevent overloading. This is crucial to avoid brownouts and blackouts. Subsequently, considerations such as fuel constraints, hydro resources, and policies are taken into account, followed by economic dispatch according to merit order. The challenge arises from the uneven geographical distribution of cost-effective and reliable power generation resources across the network necessitates Security-constrained Economic Dispatch. However, these issues often result in extensive debates between the System Operator and the National Electric Power Regulatory Authority (NEPRA) during hearings on economic dispatch. Frequently, plants are dispatched out of merit order to support local voltage and grid reliability, while more economical resources are curtailed to maintain operational reserves. Under significant pressure to implement economic dispatch, the System Operator is often compelled to make compromises on grid reliability to minimize financial losses.
HR Capacity Constraint of the System Operator
The System Operator's workforce issues extend beyond high turnover and slow hiring. It also struggles with inadequate training programs, leading to a skills gap in critical areas like system security and advanced technology. Additionally, budgetary constraints limit the ability to offer competitive salaries, further complicating recruitment and retention efforts. The lack of a robust succession planning and staff development strategy exacerbates these challenges, risking long-term operational efficiency and system reliability.
Conclusion
The combination of these factors - seasonal variability in power generation, maintenance challenges, industrial grid connectivity issues, a capacity trap, power system management complexities, infrastructure investment gaps, policy and market dynamics, along with geographical and technical constraints - collectively increase the likelihood of blackout winters in Pakistan.
To effectively prevent brownouts and blackouts, requires a comprehensive approach that encompasses regular maintenance and upgrading of power infrastructure, including plants and transmission lines. Enhancing grid management with advanced monitoring systems, diversifying energy sources with a blend of renewable and traditional options, and implementing dynamic load management are key. Additionally, strengthening the training of system operators, investing in modernizing grid infrastructure, updating policy frameworks, and developing emergency response plans are essential. These efforts, combined with improved grid monitoring and balancing economic dispatch with grid reliability, will contribute significantly to the reliability and stability of the power sector.
Writers are industry officials
