Inside Spain: 'First of its kind' blackout and dying of heat

The power surge that caused paralysing blackouts in Spain and Portugal in April was an unprecedented event in Europe and maybe the world, an expert panel investigating the event said on Friday.

"This was the most severe blackout incident in Europe in the last 20 years," Damian Cortinas, president of the association of electricity grid operators ENTSO-E, said during a presentation of a preliminary report into the incident.

He said "cascading overvoltages" were behind this "first of its kind" blackout in the continent.

"We think in the world as well," Cortinas said, while cautioning that the experts did not have all the information from every country in the world.

"This is new territory. This is also why we need a bit of time to be sure that we analyse what's going on and what would happen, but it is a first of its kind."

Overvoltage occurs when there is too much electrical voltage in a network, overloading equipment. It can be caused by surges in networks due to oversupply or lightning strikes, or when protective equipment is insufficient or fails.

The April 28th outage cut internet and telephone connections, halted trains, shut businesses and plunged cities into darkness across Spain and Portugal as well as briefly affecting southwestern France.

In other news, the number of heat-related deaths in Spain between May 16th and September 30th hit 3,832, an 87.6-percent increase from the same period in 2024, the health ministry said this week.

Nearly two-thirds of the deaths involved people over the age of 85, and almost 96 percent were over 65, it said in a statement.

The figures were estimated using statistical models, the statement said, adding that they may still be revised.

The ministry used data from Spain's Mortality Monitoring System (MoMo), which tracks daily mortality nationwide and compares it to historical trends.

It also incorporates external factors, such as weather data from the national meteorological agency AEMET, to assess likely causes of mortality spikes.

Although MoMo cannot confirm a direct cause between deaths and high temperatures, it provides the most reliable estimate of fatalities in which heat was likely a decisive factor.

Most heat-related excess deaths are due to heart attacks and strokes caused by the strain of trying to keep body temperatures stable.

The health ministry reported 25 deaths from heatstroke during the same period.

Most victims had risk factors such as chronic illnesses, were exposed to high temperatures at work or during leisure activities, or lived alone or in homes without air conditioning, it said.

Scientists have warned persistently that human-driven climate change is resulting in more frequent and intense weather events worldwide.

Spain this year sweltered through its hottest summer since records began in 1961, with an average temperature of 24.2C, according to AEMET.

Of the 90 days of summer, 33 were marked by heatwaves, AEMET said.

The country endured a 16-day heatwave in August which fuelled wildfires that killed four people and destroyed a record area of land.

That heatwave was "the most intense on record", with an average temperature 4.6C higher than average, exceeding the last record set in July 2022.

Nine of the 10 hottest summers in Spain since 1961 have occurred in the 21st century, according to AEMET.

Britain, Japan and South Korea also endured the hottest summers this year since each country began keeping records, according to their weather agencies.