Demand Flexibility avoided a blackout tonight

đź’ˇ When you mix scheduled maintenance with an unforeseen interruption due to a technical failure, anything can happen.

The truth is that the worst did not happen. The electricity supply and management of Red Eléctrica allowed the system to overcome the shock.

The facts

There was an “unscheduled” stoppage at AscĂł (nuclear power plant) due to a technical failure, which meant a significant drop in generation.

Furthermore, this was added to two other factors. The Vandellos II plant was already stopped for scheduled intervention. Finally, wind generation was less than expected.

Consequences: demand was greater than generation.

The role of the System Operator

A System Operator, like #RedElectrica in Spain, plays a fundamental role: keeping demand and supply balanced at every moment (in a matter of seconds). Within this framework, also maintain the security (and quality) of electricity supply.
The task is implemented with different services that Red Eléctrica activates in response to the type of incident or according to the need.

How the consumer can help

🏭 When generation cannot satisfy demand, Red Eléctrica intervenes to (forcefully) reduce consumer needs.
Therefore, yesterday it was up to large consumers to compensate for this failure in generation.
Red Eléctrica activated the #SRAD service or Active Demand Response Service.
In short, the service aims to adequately compensate for the reduction in consumption.
Through an auction held once a year, the industry offers its ability to lower its demand, when necessary.

The benefits of this help

In 2024, it was closed with €230,000/MW/year. That is, the availability to “be turned off” is remunerated with this amount for each MW.

In the specific case, yesterday #RedElectrica needed about 609MW, which generated a significant imbalance cost, but vital to keep the national electricity supply service standing.


Demand flexibility is a pillar of networks, even more important if we think about the volatility and unpredictability of intermittent generation, such as solar or wind.

If the green transition is headed towards the adoption of renewables, the electrical system must be prepared to compensate for fluctuations. Storage and demand flexibility play “THE” role for this evolution or revolution.

Looking ahead, I will never stop promoting how to control with A.I. Consumption in industry allows an instant reaction, in accordance with the needs of a distributed network. Unforeseen failures, as well as mathematical availability forecasts, are compensated only by reacting in real time to events that historical series could not have foreseen.