The companies complied with regulatory requirements on voltage control and even operated above regulatory obligations on the day of the outage to contribute to the stability of the electric system, according to a statement from the association mentioned today by Spanish media.
Aelec stated that the company Red Eléctrica, Spain’s electricity system operator, failed to ensure voltage control on the network on April 28, despite having adequate resources.
However, REE “decided not to dispatch” and opted to manage the voltage with limited synchronous capacity and uneven geographical distribution, the association added.
The Spanish Government presented on Tuesday the conclusions of the investigation commission formed to determine the causes of the blackout and revealed that the electrical collapse was due to a “combination of factors” causing high voltage overload on the Spanish electrical grid, which the system could not control or absorb, despite having sufficient response infrastructure.
The government attributed responsibilities to “poor planning” by Red Eléctrica de España (REE) and failures in response obligations by energy-producing companies, suspecting non-compliance with protocols for voltage overload situations.
Red Eléctrica also attributed the blackout to non-compliance by energy producers but rejected accusations of “poor planning.”
“If the generators obligated to meet dynamic voltage control — the generators connected to the system at the time of the incident — had complied, there would not have been a blackout,” said Concha Sánchez, General Director of Operation at Red Eléctrica, at a press conference.
According to REE, the blackout resulted from circumstances accumulating into a voltage overload issue, leading to a cascade stoppage of energy production facilities.
The REE inquiry concluded that significant oscillations in the system were recorded from 12:03 local time on April 28 (half an hour before the blackout), with the first apparently “forced” due to possible internal anomalies in a production unit.
Subsequent production losses occurred in the system due to units being disconnected “incorrectly.”
The first oscillation took place at a photovoltaic facility in Badajoz, which was connected to the electricity transmission grid at the time, revealed REE without further details.
These were followed by generation outages leading to the total blackout, with the first occurring in the Granada area and being done “incorrectly,” non-compliant with obligations, as system voltage was “well within legally established limits” at that time.
Thus, according to REE, these initial “unjustified” disconnections of production units, coupled with the failure of electricity generators to absorb the overload as required, led to voltage overloads outside normal limits and the blackout, without the possibility of activating system defense and balancing mechanisms.
REE denied “poor planning” by the company in the days and hours preceding the blackout, as pointed out by the Spanish Government, arguing that the collapse could have been avoided if companies with production units had complied with their obligations on that day at the operator’s request.
Neither the report presented by the Spanish Government nor the REE investigation revealed the names of the companies targeted, citing legal confidentiality issues in both cases.
