Generators reject blame for Spanish blackout as enquiry continues

Blame for the Spanish blackout that occurred last month is being shifted from excess reliance on renewables to large power generators not doing their part in managing the power system, but industry sources and commentators say more information is needed to pinpoint the cause of the event of unprecedented scale, as several investigations into the event continue.

The chair of Spain’s grid operator Red Electrica de Espana (REE), Beatriz Corredor, accused some large power plants of not doing their job to help regulate the power system, the FT reported.

While she did not say they were the root cause of the Spanish blackout, she said that the functioning of some gas, nuclear or hydroelectric plants was “below (the levels) required by current voltage control regulations.”

However in a statement in response to REE on May 27th, industry body Aelēc — which includes Endesa and Iberdrola among its members — said it wanted to “make it clear that the member companies have not identified any faults in their facilities.”

“The disconnections occurred automatically, as established by the electrical regulations, in the face of a serious situation of grid instability.”

“In other words, the protection systems acted as they should.”

Power generators that are part of Aelēc followed REE’s instructions at all times and acted in accordance with current regulations regarding voltage control, it said.

“This blackout should be an opportunity to review procedures and strengthen coordination of the electrical system,” the statement added.

It also called for more transparency and full disclosure of the technical data related to the incident.

Meanwhile, Spanish authorities have identified the starting point of the sequence of power failures in a substation in Granada.

Spain’s energy minister Sara Aagesen told lawmakers that the initial failure was followed by power losses at substations in Badajoz and Seville, resulting in generation loss of 2.2 GW, thus triggering a series of grid disconnections, Reuters reported.

She said that the government’s investigation is also looking at excessive voltage as one possible cause, adding that cyberattacks and imbalances in supply demand, as well as insufficient grid capacity, had been ruled out.

Grid operator REE said the power loss “occurred to causes outside” the grid, and potentially at generation plants and smaller grids not managed by REE.

In parallel with the Spanish government, Europe’s power TSOs network, ENTSO-E is continuing its own investigation into the causes of the blackout, having appointed a panel of ten experts from various European grid operators.

In mid-May, ENTSO-E issued a chronology of the event, which it said started at 12.32.57 on April 28th and resulted in the Iberian electricity system collapsing completely and the HVDC lines between France and Spain stopping transmitting power less than one minute later.

The restoration process was completed only at 4 am the following day.

While the ‘blame game’ between different actors continues, commentators say more information is needed to assess the real causes of the blackout.

“We are very much waiting for more information…We know there were unusual frequency events before the blackout but I haven’t seen anything yet on voltage fluctuations alongside that,” Adam Bell, director of strategy at UK consultancy Stonehaven and former head of strategy at the UK Department for Business, Energy and Industrial Strategy (BEIS) told Gas Outlook.

“It is possible that a lack of reactive power contributed, but if that’s the case then we’ll need to see the actual numbers before we say whether major power stations weren’t doing their job,” he added.

Placing the blame on large generators “is unfair” as “the ones that were online did their job but the disturbance was too big and happened so fast that they were unable to prevent it,” Mike Longson, head of market intelligence at renewable optimisation solutions provider Enspire, told Gas Outlook.

Renewable energy

A high share of renewables in the power generation mix has also been initially blamed for the blackout.

However, “solar is not the problem here…It’s the inability to weather larger losses of generation (and ) load,  which is what happened here,” he said.

“There is a lot more value in flexibility than system operators have thought,” he continued.

“Historically, systems have had large amounts of spinning generation so a ‘loss’ has had a delayed impact and there is inertia in the system.”

“With a high volume of solar these is no physical inertia therefore synthetic is needed, which hasn’t been built out yet.”

“The same case applies to large, single sited generation, the grid is reliant on these delivering rather than having smaller distributed generation, backed up by energy storage,” he added.

“The takeaway for Spain is they have done great things in shifting towards a low-cost generation but have been negligent in support mechanisms.”

“Whilst large generation has taken some of the blame it is more bad planning that has prompted this.”

“No energy grid is completely infallible, and blackouts have always been a possibility, both (in the UK) and around the world,” Kate Mulvany, principal consultant at Cornwall Insight, told Gas Outlook.

“Systems have become more reliable over time, but vulnerabilities remain, including in countries where fossil fuel has been relied upon.”

In the UK, NESO, in conjunction with the electricity market, has “invested heavily in developing robust systems and processes to prevent outages,” she said.

“A key part of that effort has been the development of new balancing and system management tools, particularly the integration of grid-scale batteries, which play a vital role in maintaining stability,” she added.

(Writing by Beatrice Bedeschi; editing by Sophie Davies)