The recent widespread blackout on the Iberian Peninsula has ignited a debate about power grid stability, prompting governments, utilities, and power suppliers in Japan to reconsider measures to prevent major local outages.

The April 28 outage plunged large parts of Spain, Portugal, and Southern France into darkness, sparking speculation about causes such as cyberattacks or geopolitical conflicts. While the event caused local panic, it also raised serious concerns in Japan about the possibility of a similar scenario. These concerns are not unfounded.

In the past decade, Japan’s vulnerability to natural disasters – including earthquakes, typhoons, and frequent torrential rains – has led to numerous power outages. While the earthquake of March 11, 2011 remains the most infamous date, many local outages receive less media attention despite serving as both symptoms and stress tests of energy security.

As the global community seeks to shift from fossil fuels to renewable energy, discussions on energy security are politicized, often overlooking grid stability. The Iberian blackout offers an opportunity to revisit the complexities of Japan’s power grid, which relies on frequency control, inertia, interconnection capacity, and demand forecasting.