Shared power: The Growing Importance of BESS in Pakistan’s Renewable Power System

• Waqar Mohammad -GM-BESS (A2Z Energy Systems)

Pakistan’s power sector is undergoing a rapid transition from fossil fuels to renewable energy. Solar and wind power are adding cleaner sources of electricity to the national grid. Solar panels are now common on residential and industrial rooftops, while wind turbines are increasingly being installed in industrial zones, particularly in southern Pakistan. At the same time, many industries are developing their own captive power systems to cope with unreliable electricity supply caused by weak transmission and distribution networks, especially in areas located far from major grid centers. All of these developments are happening simultaneously, placing new pressures on grid stability and system operation.

In the past, the grid was primarily powered by large conventional power plants equipped with heavy rotating machines. These machines naturally provided inertia. In simple terms, they acted like flywheels. Whenever there was a sudden disturbance—such as a large load switching on or a generator tripping offline—the system did not react immediately. The stored kinetic energy in these rotating masses helped slow down the change, giving grid operators valuable time to respond and maintain system stability.

Today, however, a growing share of electricity comes from renewable sources such as solar and wind. Unlike conventional generators, these resources do not connect directly to the grid. Instead, they operate through power electronic converters, commonly known as inverters. While inverters are highly efficient, flexible, and fast-acting, they do not provide physical inertia. As their penetration increases, the grid gradually loses part of its natural ability to withstand sudden disturbances. As a result, system frequency can rise or fall more rapidly, and voltage stability can become increasingly difficult to maintain.

This is where Battery Energy Storage Systems (BESS) become critically important. Many people think of batteries simply as a means of storing energy. While that is true, it is only part of the picture. A modern BESS is far more than just a battery bank. It includes advanced power conversion systems capable of injecting or absorbing power almost instantaneously. This enables BESS to support the grid in ways that were previously impossible.

For example, during a sudden drop in system frequency, a BESS can respond within milliseconds by injecting power into the grid almost immediately. This capability, known as fast frequency response, helps slow the rate of frequency decline and improves system stability. In some cases, BESS can even emulate the effect of inertia by responding to the rate at which frequency changes. Similarly, on the voltage side, the system can supply or absorb reactive power to maintain voltage within acceptable limits. It can also smooth power fluctuations and reduce flicker, particularly in weak or highly variable networks.

These capabilities make BESS a highly valuable tool for modern grid support. However, implementing such systems in real-world networks is far more complex than it may appear. Pakistan’s power system presents several unique technical and operational challenges that must be carefully considered.

One of the most significant challenges is the existence of weak electrical networks. In many parts of the country—particularly at the distribution level—the grid lacks sufficient strength and stability. In such systems, even relatively small changes in power flow can lead to noticeable voltage variations. This becomes particularly problematic when fast-acting inverter-based resources are connected. Their control systems depend on stable voltage and frequency conditions. If the grid itself is unstable, these controls may interact negatively with the network, potentially leading to oscillations, instability, or even system trips.

Another major challenge is the growing use of industrial microgrids. Many factories now operate a combination of energy sources, including the utility grid, diesel or gas genera tors, solar PV systems, and, in some regions, wind turbines. Integrating these diverse resources into a coordinated and stable system is not always straightforward. Questions such as who controls system frequency, how load sharing is managed, and what happens during a sudden utility outage are practical issues that engineers regularly face in the field.

In such environments, adding a BESS can provide substantial benefits—but only if the system is properly designed, configured, and integrated. Otherwise, it may introduce additional operational complexity. For example, during a grid disturbance, the battery may be required to support the system. However, if its state of charge is already low, should it prioritize self-protection or continue supporting the grid? These are important operational trade-offs that require careful planning and sophisticated control strategies.

Protection systems also present a major area of concern. Traditional protection schemes were originally designed for conventional power systems with large synchronous generators capable of supplying high fault currents. Inverter-based resources, including BESS, behave very differently. To protect their internal components, they intentionally limit fault current contribution. As a result, during a fault condition, the current may not increase sufficiently for older protection systems to detect and isolate the fault correctly. As inverter-based technologies become more widespread, existing protection philosophies and schemes will need significant review and modernization.

Economic considerations are equally important. Battery systems still represent a major capital investment. If they are used solely for energy storage, the financial return may be difficult to justify. However, when BESS is utilized for multiple applications—such as frequency regulation, voltage support, peak shaving, backup power, and renewable energy integration—the overall value proposition becomes far stronger. Nevertheless, for large-scale deployment to succeed, Pakistan will require clear regulatory frameworks and market mechanisms. At present, there is no fully developed market for ancillary services such as frequency regulation or reactive power support. Without such mechanisms, it becomes more difficult for investors and industries to justify these investments financially.

Despite these challenges, the overall direction is clear. Power systems around the world are moving toward higher shares of renewable energy, and Pakistan is no exception. As this transition accelerates, traditional methods of maintaining grid stability will no longer be sufficient on their own. New technologies, advanced controls, and modern operational strategies will be essential.

Battery Energy Storage Systems are one of the key technologies enabling this transition. While they are not a complete solution by themselves, they can play a vital role in supporting modern power systems. Their speed, flexibility, and controllability make them exceptionally well suited for the evolving needs of today’s grid. The key lies in deploying them intelligently—based on detailed system studies, robust control philosophies, and a deep understanding of local grid conditions.

Ultimately, the transformation underway is not only about introducing new equipment; it is about redefining how the grid is understood, operated, and managed. Stability is no longer determined solely by large rotating machines and mechanical inertia. Increasingly, it depends on advanced control systems, coordination between distributed resources, and intelligent system design. If managed carefully and strategically, this transition can lead Pakistan toward a more reliable, resilient, and sustainable power system for the future.

Copyright Business Recorder, 2026