Spain's grid denies dependence on solar power to blame for blackout

MADRID (Reuters) -Spain's grid operator denied on Wednesday dependence on solar power was to blame for the country's worst blackout, while Prime Minister Pedro Sanchez came under increasing pressure to explain what went wrong.

With life returning to normal after a power outage that halted trains, shut airports and trapped people in lifts, Sanchez's opponents pointed the finger at low investment in a system that increasingly relies on intermittent solar and wind power.

Sanchez has announced a government investigation and said he was seeking answers from private energy companies that feed power into the grid. He also said he has not ruled out a cyber attack, although this has been dismissed by part-state-owned grid operator REE .

Spanish authorities are still dealing with the political fall-out from deadly floods in the east and south of the country that killed more than 220 people.

REE, which is headed by former Socialist minister Beatriz Corredor, has narrowed down the source of the outage to two separate incidents of loss of generation in substations in southwestern Spain, but says it has yet to identify their exact location and that it is too early to explain what caused them.

In an interview with Cadena SER radio, Corredor said on Wednesday it was wrong to blame the outage on Spain's high share of renewable energy.

"These technologies are already stable and they have systems that allow them to operate as a conventional generation system without any safety issues," she said, adding she was not considering resigning.

Just before the system crashed, solar energy accounted for 53% of electricity production, wind for almost 11% and nuclear and gas for 15%, according to REE data.

The share of renewables as a source of electricity production in Spain has grown to 56% in 2024 from 43% a decade earlier, according to REE. Spain is targeting 81% by 2030.

Energy Minister Sara Aagesen said the government had given power companies a deadline of late on Wednesday to provide data for "every millisecond during those five seconds" when the system on Monday experienced a huge loss of generation, triggering a disconnection from the rest of Europe.

One problem on Monday was that there was not enough backstop stable power, such as gas and nuclear, to handle the sudden fall of power generation, an industry source said.

"The problem wasn't so much the massive entry of renewables, rather the lack of synchronous generation," the source said.

'MALFUNCTIONING OF REE'

Political opponents said Sanchez was taking too long to explain the blackout, and suggested he was covering up for failings at REE.

"Since REE has ruled out the possibility of a cyber attack, we can only point to the malfunctioning of REE, which has state investment and therefore its leaders are appointed by the government," Miguel Tellado, a parliamentary spokesperson for the opposition conservative People's Party, said in an interview on RTVE.

He called for an independent investigation to be conducted by Spain's parliament rather than the government probe Sanchez has announced.

REE itself warned in May 2024 of the risks of a major outage. Renewable sources are spread across the country's territory and connect to substations that were not designed to handle high volumes of generation, it said in a report.

To withstand sudden oscillations in frequency, the grid needs to invest in load-shedding relays to act as shock absorbers when there's a plunge in generation, REE said.

Spain's government said it had asked private energy companies for "maximum collaboration and transparency" to help identify the cause of the outage.

Ignacio Sanchez Galan, executive chairman of Spain's largest energy company Iberdrola, said the company's operations were not at fault and it was REE that should clarify the reasons for the blackout.

The outage could have been caused by a lack of supply from stable sources such as gas, nuclear or hydropower on the day and an excess of unstable sources such as sun and wind that caused a disparity when there was a drop in demand, Jorge Sanz, former president of the Commission of Experts on Energy Transition Scenarios, told TVE.

This caused transport networks to disconnect as a precaution and triggered a collapse of the grid, he said.

The government expects private and public investment of some 52 billion euros through 2030 to upgrade the power grid so it can handle the surge in demand from data centres and electric vehicles. Aelec, the utility lobby, has said that is not enough.

Jordi Sevilla, REE's chair until 2020, wrote in an opinion piece in Cinco Dias newspaper that the government was moving too fast to decommission nuclear power plants that can provide stable generation to offset the peaks and troughs of intermittent renewable energy.

(Reporting by David Latona, Pietro Lombardi and Aislinn Laing in Madrid; Writing by Charlie Devereux; Editing by Peter Graff and Barbara Lewis)