Why we are solving the wrong problem over grid resilience

It’s been one year since Spain’s 2025 blackout, and the energy industry has spent the last 12 months analysing what happened and how to prevent a repeat.

In the months since the major outage, response has focused on adding capacity, rather than addressing how to modernise the grid to avoid a similar situation. We have seen the industry return to a familiar playbook: build more power plants, reinforce transmission, and pour money into infrastructure.

However, since the incident, it has become clear that it was not a matter of supply shortage, but rather a grid that struggled to respond as conditions changed. The grid was unable to rebalance quickly enough as multiple stresses emerged at once, causing the major outage.

The grid is struggling to keep up with today’s energy demands. Operating conditions have fundamentally changed, with rapid load growth from data centres, electrification, intermittent renewable generation, and increasingly volatile demand from extreme weather events. 

Under these conditions, reliability is no longer defined solely by how much available capacity, but by how quickly and accurately the grid can react when something unexpected occurs.

Expansion isn't enough 

When the grid is under stress, the usual response has been to add more generation and build new transmission lines. This strategy is still important for keeping the lights on, but it’s no longer a sufficient resiliency strategy with how quickly the grid is changing. 

Getting new infrastructure up and running takes years, with delays for permits, funding, and construction. Meanwhile, demand is increasing, while renewables can be intermittent due to weather and time of use. 

That’s leading to a bigger gap between how quickly the grid's needs are changing and how quickly we can build to keep up.

What makes events like Spain's blackout particularly challenging is they expose the limits of this approach alone. 

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They rarely stem from a single failure point. Instead, they emerge from multiple stresses that converge until the system can no longer rebalance itself quickly enough. When generation drops unexpectedly, transmission is constrained, or demand increases faster than forecast, the grid must respond immediately. 

If those responses are delayed or limited, small imbalances can escalate rapidly into exponentially larger disruptions. This is where flexibility becomes critical, as the system must be able to respond in real time to build resiliency against failures, not just rely on additional capacity. 

The lesson from Spain should not be confined to supply adequacy alone but should prompt a broader reassessment of how flexibility is incorporated into grid operations as a frontline defence.

Innovation is critical 

The rapid growth in demand is not just placing strain on the grid; it is accelerating long-overdue innovation in how it operates. Events like Spain’s blackout highlight that the issue is not just how much demand is on the system, but how effectively that demand can be managed in real time. 

Large energy users like data centres and manufacturing facilities drain significant power from the grid, but they can also be much more flexible power users than traditionally assumed. 

With the right systems in place, they can dynamically adjust how much and when they consume power, in alignment with real-time grid conditions, turning demand into something the grid can manage more effectively. 

In moments of stress, this kind of flexibility helps the system rebalance faster, reduce the risk of cascading disruptions, and respond more effectively to changes without immediately requiring new infrastructure.

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While traditional demand response programmes are meant to make the grid more flexible, they are historically only leveraged during peak demand or emergencies. Typically, these programmes rely on manually shutting things off or making system-wide cutbacks. 

That approach can help, but it doesn’t really fit a grid that faces constant swings in supply and demand. In fast-moving failure scenarios, delayed or manual responses limits the effectiveness of these programmes.

To combat these limits, the industry is starting to adopt more continuous and coordinated ways of managing demand. By combining real-time data, forecasting, and automation, operators can adjust demand as conditions change, making flexibility part of everyday operations and not just a backup plan.

This shift is redefining the role of large energy users in grid reliability, from passive sources of demand to active participants in maintaining stability. For utilities, this opens up new opportunities to improve resilience by adding (leveraging) more flexibility, rather than depending on long-term infrastructure buildouts.

Reliability depends on flexibility 

Spain's blackout reinforced the need for stronger infrastructure, but it also exposed a gap in how the system operates under stress. It showed that reliability isn't just about having enough power but instead depends on how quickly and effectively the grid can respond to changing conditions to manage disruptions in real time. 

The grid is no longer operating under predictable conditions, and performance increasingly depends on speed, coordination, and precision.

More capacity will always play a role in strengthening the grid, but it isn’t the only solution. 

Systems that can adjust in real time are better equipped to manage volatility than those built around static assumptions. 

The grid needs to be more flexible and better coordinated, or the same risks can persist even as the system modernises.

About the author: Jeremy Ellis is the Director of Power Strategies at flexible load solutions company OBM.