Future Power Systems

 Planning for uncertainty in the long-run and designing for strategic flexibility

Authors: 

João Graça Gomes, Dyson School of Design Engineering, Imperial College London;  Future Energy Leaders, World Energy Council
Michel-Alexandre Cardin, Dyson School of Design Engineering, Imperial College London
Billy Wu, Dyson School of Design Engineering, Imperial College London

No matter how rigorously we try to forecast the long-term needs of the power sector, our predictions are invariably wrong. Trends shift, technology advances, and even the most advanced electricity grids can be vulnerable. A recent widespread blackout across the Iberian Peninsula (Portugal, Spain, and Andorra) and parts of southern France is a clear reminder of this.

What happened?

As of now, the exact cause remains still under investigation. Full clarity may take many months and require independent reviews. However, here’s what we’ve learned so far. The blackout began at 28 April, just after noon, a sudden power failure at a substation in southern Spain caused a chain reaction.

Two main explanations have emerged. One suggests that a miscalculation in the energy mix led to a voltage surge that destabilized the grid. According to a Spanish government report, several conventional power plants failed to respond in time, which worsened the situation and triggered a wave of shutdowns across the network. This thesis attributes the fault on poor energy planning and management, since it says there was not enough backup, not enough control, and not enough power plants responding to this emergency.

The alternative perspective also acknowledges that a voltage surge was the initial trigger but attributes the blame solely to conventional power plants for failing to regulate the voltage levels. Pointing to anomalies in the disconnection of power plants and an unexpected spike in electricity demand from the transport network.

The debate over what went wrong, and who is responsible, remains unresolved.

How was power restored?

Power was gradually restored over several hours. Spain recovered faster than Portugal, partly because it has more connections to neighbouring countries. In Portugal, the process took about 12 hours, partly because there were only two power plants able to restart the grid from scratch (black-start capacity). The recovery required careful coordination and was helped by the fact that hydroelectric dams were full due to a wet year.

What can we learn?

In the immediate aftermath, many experts have rightly called for a renewed focus on classic resilience measures:

• Increasing the number of power plants with black-start capacity.
• Building more connections between countries, especially between Iberia, France, and Morocco.
• Modernizing the grid with new technologies.

These are essential priorities. But they are not enough.

Rethinking resilience

The blackout should prompt a broader reassessment of how we think about power system reliability in the 21st century, and beyond. Ironically, the very success of modern grids, so reliable they are rarely questioned, has lulled us into complacency. We design for what we expect, not for what might blindside us.

In recent decades, the power sector has increasingly embraced new approaches to address uncertainty in long-term design and planning. Sophisticated machine learning methods for forecasting energy markets or optimisation methods for generation expansion planning like stochastic programming, robust optimization, and scenario-based modeling are slowly becoming part of planning processes in industry and government, especially with the rising integration of variable renewable energy sources.

Despite these advancements, important challenges persist. While current methods offer better ways to anticipate future outcomes, most still rely heavily on predefined assumptions and historical data. These tools, as valuable as they are, often fall short when confronted with the unexpected, whether when disruptions happen at very small timescales (seconds to minutes, like extreme weather events), medium timescale (weeks to months, like temporary geopolitical disruptions), or longer timescale (months to years, like technological shifts). To build truly resilient power systems, we must go beyond standard forecasting techniques and start incorporating the capacity to adapt dynamically as events unfold.

Strategic flexibility

This is where strategic flexibility comes in. Strategic flexibility advocates that systems should be designed from early conceptual activities to be more adaptive, flexible, in the sense that they can change, evolve, and reconfigure to manage uncertainty and risks. It promotes embracing uncertainty early on in design and deploying an architecture enabling system operators to make value-enhancing decisions over time, as opposed to locking the system down a particular design or technological path. This could mean designing assets that can be scaled up or down as demand shifts, systems that can switch between different fuel sources as technology evolves, or modular infrastructures that can be deployed incrementally or reconfigured as part of an emergency response plan. These “real” options are not just theoretical, they are already proving extremely valuable in many industry sectors like aerospace, transportation, and water management, and it´s time for the energy sector to do the same.

Decentralized and flexible solutions

Strategic flexibility prone development of decentralized energy systems and markets in the future. This is because it recognizes economic and social value from modularity that cannot be properly assessed using standard appraisal methods like net present value analysis. For example, studies show that decentralized solar PV has enormous potential to increase resilience, but under current rules, most installations are still grid-tied and automatically shut down during outages. Enabling off-grid capabilities in critical locations, hospitals, military bases, governmental authorities, supported by batteries or a mix of wind-solar-diesel power systems, can help sustain essential services during blackouts. These investments may carry a slightly higher upfront cost to engineer the ability to adapt, but the long-term value in resilience, security and sustainability can be worth many times the return on investment.

The role of technology

Immersive technologies like virtual reality, and serious-gaming, can also play a critical role to support better design and planning in the future. Advanced control systems, and real-time analytics can enable faster, smarter responses during grid disturbances simply by providing an environment to carefully train operators on dynamic adaptation plans. Integration with virtual replicas of physical systems can allow them to simulate and prepare for rare events, stress-testing scenarios that traditional planning might overlook.

Looking ahead

Building a resilient power system isn’t just about stronger wires and faster repairs. It’s about creating networks that can adapt and evolve over time. As we look to the future, we must focus on flexible, responsive planning that embraces uncertainty. Addressing these issues, and learning from past experiences, are foundational to ensuring successful energy systems for generations to come. 

Only World Energy Congress unites the key players from across the energy ecosystem for a comprehensive, systems-wide approach, to learn with and from each other to make faster, fairer, and more far reaching energy transitions happen. Under the topic of ‘Securing a resilient future’ - a central pillar of the World Energy Congress 2026 programme – leaders and experts will convene to explore the diverse energy transition pathways and approaches across the world, and how cities and nations are extending resilience beyond systems to people and communities.

We can’t predict every challenge the future will bring, but together, we can design our energy systems to handle whatever comes next.