Portugal suffered another major power outage, this time in the northern part of the country on the border with Spain. The outage left over 80,000 people in the Viana do Castelo district without power.

The Portuguese Civil Protection Agency (ANEPC) reported that the source of the problem was a serious fault at a hydroelectric power plant in France. “The cause of the failure remains unknown, but all available resources have been directed to addressing the incident,” ANEPC officials said in a statement cited by Do Rzezcy.

This is the second mass blackout this year. Back in April, power outages affected all of Spain, large areas of Portugal, and parts of southern France. 

At the time, Spanish operator Red Electrica warned in a report for investors: “The closure of conventional power plants, such as coal-fired, combined-cycle, and nuclear, will result in a reduction in the power system’s sustained capacity and balancing capacity, as well as its capacity and inertia.”

Experts have long been warning that the power grid on the Iberian Peninsula is overloaded.

“Most likely, in Spain, we were dealing with a situation where a very large number of photovoltaic plants were producing electricity and suddenly either stopped or increased production. A blackout can occur both with an energy surplus and a shortage,” explained Wojciech Płachetka in an interview with Polish journalist Igor Janke.

Professor Władysław Mielczarski from the Lodz University of Technology shares a similar opinion: “Spain is moving away from stable sources too quickly, and the grid was overloaded with wind turbines and panels. There was a lack of traditional synchronous turbines.”

Although Portuguese Prime Minister Luis Montenegro announced investments in grid modernization and warning systems after the April blackout, Wednesday’s outage shows that the problem remains unresolved. Experts warn that if this trend continues, Europe could face further power outages in the coming years, including beyond the Iberian Peninsula.