What we can learn about building a resilient energy grid from the Iberian power outage

How can modern society operate in a world without electricity? The Iberian Peninsula recently faced the stark reality of this challenge, when it suffered Europe’s largest blackout in two decades.

April’s outage left tens of millions of people in Spain and Portugal without power and impacted transport, banking and communication networks, while hospitals relied on back-up generators.

This was not the first disruptive power outage in Europe this year. In March, London Heathrow Airport closed after a fire at the only substation providing power to one of the world’s busiest transport hubs, cancelling flights and leaving thousands of homes without electricity. The cause of the blaze remains unknown, but the overall cost to the airline industry is estimated at over £60 million ($78 million).

Both incidents highlight the urgent need to improve the overall preparedness and resilience of power systems, amid rising global electricity demand, the clean energy transition and increasingly frequent hazardous climate events.

The good news is that solutions exist for the private and public sectors to avoid future costly energy disruptions.

The Iberian power cut on 28 April served as a wake-up call for grids.

Before exploring what happened that day, one must understand that a secure and reliable power system operates within a constant voltage range, maintains specific frequency thresholds and continuously balances supply and demand.

In addition, stability and security are often enhanced by the connection of national grids across borders. In this case, Spain’s is connected to France and Portugal to enable electricity trading and enhance security.

What we currently know about the incident is as follows, as presented by EPRI and ENTSO-E:

Various theories on what caused or contributed to the incident have been mooted, including speculation that renewable energy was to blame. Theories such as interarea oscillations, cyberattacks and rare atmospheric phenomena have been eliminated.

Spanish transmission system operator Red Eléctrica and the European Commission have launched separate investigations into the incident. But, regardless of the cause, the outage highlighted how power grids need to be more resilient and futureproofed.

In advanced economies such as Europe and North America, power systems were designed supporting central generation and one-directional power flows, built to suit a stable climate that no longer exists. These systems need to be updated to address today’s energy realities, which include:

Such pressures are not insurmountable. Redundancy and contingency planning can evolve and ensure the functioning of current infrastructure. These challenges must also not slow the clean energy transition – instead, strengthening resilience is essential to advancing the shift to low-carbon power, while withstanding the dual pressures of rising demand and escalating climate threats.

Incidents like the Iberian blackout ultimately reveal deeper resilience gaps. Power systems have embedded resilience by design; however, in the current landscape, this must be enhanced. There are a suite of solutions to support this:

Iberia’s outage showcased that inertia was missing in the system. As fossil fuels are replaced by cheaper and cleaner sources of energy, the energy grid must adapt to new reliability and storage challenges, which can be addressed by technologies like pumped hydro storage, battery energy storage systems, flywheels and synchronous thermal energy.

Increased deployment of renewable energy sources can strengthen the system’s resilience by decentralizing power generation. Looking ahead, new types of grid support services may also emerge across jurisdictions to provide both inertia and flexible backup power when needed.

To strengthen grid reliability and prevent blackouts, policy-makers should consider connecting power grids across national borders. Interconnections can be part of a multilayered resilience strategy, enabling the sharing of electricity resources during emergencies, with added benefits such as market competitiveness.

Although in the case of the recent blackout interconnections were more of a contributing factor and Portugal was subsequently affected, in other cases like the Texas hurricanes in 2021, power sharing with other regions could have saved nearly $100 million in damages per gigawatt of interconnection. Such strategies require cross-border collaboration, grid code harmonization and robust regulatory frameworks.

The system must also deploy storage solutions to complement renewable generation and provide firm power, or act as a fast response in case of an electricity mismatch. Building system flexibility through smart infrastructure, demand-side management and decentralized microgrids can help ensure a dynamic and secure energy grid.

At the same time, grid operators must ensure that clean energy is both available and able to stabilize the grid – ideally using grid-forming inverters. These investments can be utilized in response to climate hazards as well.

Various actions can be taken to address climate hazards. Preventative measures, including sustainable vegetation management, weather monitoring and forecasting of dynamic line rating, could proactively mitigate risks and losses.

As listed utilities companies are expected to suffer climate-induced losses to property, plant and equipment by 2035 of between $33-37 billion, heat-resistant infrastructure and cooling technologies are also needed.

Meanwhile, AI and real-time data can be leveraged for tech-driven solutions such as climate impact modelling or energy early warning systems, which use Earth observation and internet of things sensors to identify climate hazards along the value chain before the grid infrastructure is compromised.

The operational needs of energy systems must also be tackled. To maintain energy security, it is essential to define clear roles, incentives and regulations throughout the electricity sector.

This can be done by institutionalizing responsibilities and incentives, while systematically identifying and mitigating risks, strengthening both prevention and recovery mechanisms.

Cross-industry collaborations can enable sharing of best practices and drive collective progress towards climate adaptation and system resilience, while public-private partnerships can drive a systemic approach to energy generation, transition and resilience to avoid large-scale blackouts.

These proactive strategies strengthen grid resilience and provide reliable electrical infrastructure. Without them, communities and businesses will continue to face disruptive and costly power failures like the Iberian blackout. By working together, we can transform today’s energy vulnerabilities into tomorrow’s adaptive advantage.

The authors would like to thank Marta Wilhelmi Corona (ECP 2025, Climate Resilience and Adaptation) and Flora Mccrone (Lead, Immersive Interactions, Centre for Nature and Climate) for their valuable contributions and feedback.