The Duck Curve challenge

As the world embraces the era of energy transition, Pakistan stands at a critical juncture where adopting a Just Energy Transition mechanism is not just a choice but an imperative to safeguard the environment. Among the technologies driving this change, photovoltaic (PV) solar energy has emerged as a disruptive force, offering the promise of greener and more affordable energy. However, this rapid shift is not without challenges, as it has triggered what some experts term the “utility death spiral.”

Contrary to popular belief, the grid remains indispensable, even in an age dominated by renewable energy sources. While solar energy is transformative, the grid plays a crucial role in interconnecting diverse generation technologies; such as hydropower, nuclear, wind, solar, and thermal—to complement each other for grid stability while serving an entire eco-system of consumers while the distributed energy resources (DER) serve only a handful. The notion that we can fully replace the grid is premature; rather, its evolution is essential to sustain the energy transition.

While PV solar energy is a game-changer it is not without limitations. It struggles to support base load demand and lacks the attributes of a dispatchable resource, which are critical for ensuring a stable and reliable power supply. Technologies that provide frequency and voltage regulation, as well as the capacity to absorb the starting current of heavy equipment, are vital to complement solar energy’s intermittent nature.

Grid-forming technologies, such as grid forming inverters and battery energy storage systems (BESS), hold significant promise for enhancing grid stability. However, in Pakistan, the absence of a comprehensive BESS policy keeps this solution out of reach for the foreseeable future. Until these policies are implemented, the full potential of renewable energy integration will remain untapped.

Research highlights a pressing concern: the rapid pace of solar penetration during daylight hours, driven by falling solar prices, is accelerating Pakistan’s central grid toward the Duck Curve phenomenon. This phenomenon refers to the mismatch between peak solar generation during the day and peak electricity demand in the evening, creating a “duck-shaped” graph of energy demand versus supply.

The resulting surplus energy during the day and steep ramp-up in evening demand strain the grid, jeopardizing its stability. The challenges become particularly pronounced during Pakistan’s foggy and smog-filled winters, when flexibility in the grid is crucial to maintain stability. Without adaptive measures these seasonal challenges could intensify.

In this context, Pakistan must act swiftly to develop policies and technologies that ensure a balanced and resilient energy ecosystem. Only by embracing a multi-faceted approach that includes renewable energy, grid enhancements, and innovative storage solutions can the nation navigate the complexities of energy transition effectively.

Globally, many countries have encountered the challenges posed by the Duck Curve and have adjusted their energy policies to address this phenomenon. The Duck Curve, characterized by a surplus of solar generation during the day and a sharp ramp-up in demand as the sun sets, has driven policy innovations worldwide. However, the realities of energy demand remain persistent; no country has enough rooftop solar or battery storage to completely eliminate grid dependency, particularly for nighttime energy needs.

Our research highlights a significant shift in Pakistan’s grid dynamics. Two years ago, the peak demand occurred between 4:00 PM and 5:00 PM, but it has now shifted near midnight, coinciding with the end of peak hours at 11:00 PM or later.

This shift necessitates re-evaluation of Time-of-Use (TOU) policies and rate designs. Pakistan must implement policies that address these changes both technically and economically, such as leveraging Battery Energy Storage Systems (BESS) for grid stability, peak shaving, and integrating them with slow-ramping central power plants during nighttime demand surges.

To navigate these challenges, Pakistan urgently needs robust rules and regulations for DERs. This includes revisiting Distribution Code to ensure all DERs—particularly behind-the-meter solar installations—are controllable and do not compromise grid stability. Issues such as reactive power support and higher voltage levels must be managed to avoid potential grid collapse. Properly regulating DERs will ensure they complement rather than disrupt the grid.

The need for energy equity

The rapid adoption of PV solar as a disruptive technology has raised critical questions about energy equity. While rooftop solar and net-metering systems provide substantial benefits, such as lower electricity bills and energy independence, they also create disparities. Customers without rooftop solar, particularly those in underserved or rural areas, continue to rely solely on grid power and may face higher costs due to the shifting burden of grid maintenance onto non-net-metered consumers.

Moreover, higher buyback rates for solar energy have compounded these inequities. For instance, as more consumers adopt distributed solar systems, grid-fixed costs are increasingly borne by fewer, often less-privileged, consumers. This dynamic raises serious concerns about fairness and accessibility, particularly in regions that already endure poor power quality and extended load shedding.

Energy equity is a multidimensional challenge, requiring a balance between innovation and inclusivity. It is structured around four foundational pillars:

1. Distributional equity: Ensuring the fair allocation of benefits and costs across all demographics;

2. Procedural equity: Involving all stakeholders in decision-making processes;

3. Recognitional equity: Acknowledging and addressing the unique needs of marginalized groups;

4. Restorative equity: Rectifying past injustices in energy access and resource allocation.

For Pakistan, achieving comprehensive energy equity demands systemic reforms that address these pillars. Policies must ensure the benefits of cleaner and more resilient energy systems reach all communities, including rural and underserved populations. Without proactive measures, the energy transition risks exacerbating existing social inequities.

As Pakistan continues to transition its energy systems, it is essential to prioritize both technical innovation and inclusivity, ensuring that all citizens benefit from a cleaner, more sustainable energy future.

A Distributional Equity Assessment (DEA) is a critical tool for advancing fairness in the energy transition, with a primary focus on distributional equity, ensuring that the benefits and burdens of the energy system are shared equitably among various customer groups. While DEA emphasizes distributional aspects, it often intersects with other equity dimensions to provide a holistic perspective.

The DEA framework evaluates how costs and benefits are distributed across customers with differing characteristics, offering insights that complement benefit-cost analyses for utility investments in DERs. It addresses pivotal questions, such as: should a new DER programme be initiated or funded? Is an existing programme viable, or does it need adjustments? How should investments be prioritized across multiple DER initiatives to maximize equity and impact?

By providing a structured approach, DEA helps utilities and policymakers design programmes that balance customer needs with systemic equity considerations, ensuring that investments in DERs do not exacerbate existing disparities but instead foster inclusive growth and access to sustainable energy.

As Pakistan navigates its energy transition, embracing frameworks like DEA and implementing robust policies for DERs and grid stability are essential to achieving both sustainability and equity. By prioritizing inclusivity and proactive planning, Pakistan can ensure that the journey towards a greener future benefits every segment of society, leaving no one behind.

Copyright Business Recorder, 2024