Miscalculation by Spanish power grid operator REE contributed to massive blackout, report finds

Spanish grid relation REE's nonaccomplishment to cipher the close premix of vigor was 1 of the factors hindering the grid's quality to header with a surge successful voltage that led to the monolithic blackout crossed Spain and Portugal connected April 28, a authorities probe concluded.

The report, made nationalist connected Tuesday, besides blames powerfulness generators for the worst-ever blackout to person deed Spain and Portugal, since immoderate accepted powerfulness plants, specified arsenic atomic and gas-fired plants, failed to assistance support an due voltage level successful the powerfulness strategy that day.

"The strategy did not person capable voltage power capabilities," Spanish Energy Minister Sara Aagesen told a quality briefing successful Madrid.

"Either due to the fact that they were not sufficiently programmed, oregon due to the fact that those that were programmed did not adequately supply what was required by the standard, oregon a operation of both," she said.

While respective factors played a relation that day, Aagesen confirmed that the eventual origin was a surge successful voltage that the grid was incapable to absorb. It triggered a cascade of disconnections of generation.

Voltage surges tin beryllium caused by aggregate factors ranging from lightning strikes, faulty equipment, oregon grid instability. The probe pointed to grid instability earlier that morning.

REE, which is partially state-owned, did not person capable thermal powerfulness stations switched connected erstwhile the voltage surge caused a concatenation absorption starring to the powerfulness outage, Aagesen said.

REE "told america that they made their calculations and estimated that (switching connected much thermal plants) was not indispensable astatine this time. They lone acceptable it for the aboriginal hours of the day, not the cardinal hours."

The blackout caused monolithic gridlock successful cities and near thousands stranded connected trains and successful elevators crossed the Iberian peninsula.

Power plants "should person controlled voltage and, moreover, galore of them were economically remunerated to bash so. They did not sorb each the reactive powerfulness that was expected," Aagesen said.

Utilities lobby Aelec, which represents Spain's main energy companies including Iberdrola and Endesa, said successful a connection it agreed that voltage power was the main origin of the outage, adding that "the work for ensuring specified power lies with" REE arsenic strategy operator.

It has grounds that the powerfulness plants controlled by the companies it represents "have complied with the regulatory requirements regarding voltage control" adjacent "operating supra the regulatory obligations" to assistance stabilise grid.

Despite having capable resources to warrant voltage control, REE "opted to negociate voltage with constricted synchronous capableness and an unbalanced geographical distribution, which near the strategy successful a susceptible situation," it said.

REE did not instantly reply to requests for comment. Its president volition clasp a property league connected Wednesday.

The authorities said connected Tuesday it would suggest measures to fortify the grid and amended its quality to power voltage successful the system. It would besides propulsion to further integrate the peninsula with the European grid, it said.

Pratheeksha Ramdas, Senior New Energies Analyst and Iberia powerfulness marketplace adept astatine Rystad Energy said the incidental highlighted the indispensable relation thermal powerfulness plants, particularly gas-fired plants continued to play.

"It appears that the blackout reflects a captious nonaccomplishment successful the Spanish energy strategy not owed to deficiency of installed capableness but owed to mismanagement of disposable vigor resources and accountability successful grid operations," Ramdas said.