Spain's central government was warned in January about potential grid failure due to renewable energy overload

New information about the central government's awareness of the possibility of a massive power outage in Spain has been released. The Ministry for Ecological Transition (Miteco) knew, since at least 24 January, that the massive integration of renewable energies in the system could cause failures if necessary changes were not introduced. The ministry, headed by Sara Aagesen, had been warned by Spain's national electricity grid operator - Red Eléctrica de España (REE).

REE had proposed to update the action plan after the massive entry of renewables in order to manage the disturbances that the electricity system could suffer. The proposal was made in an internal document published by El Periódico de la Energía in May 2024. An example of the failures it referred to occurred during the historic blackout on 28 April - just a week ago.

"The need to revise the existing general protection criteria to adapt them to the new needs of the electricity system and the new technologies available has arisen," stated the report. The current criteria protocol dates back to 1996, which indicates an outdated status.

Sara Aagesen's ministry has confirmed that REE's proposal was subject to public consultation. She said that her department had been working on it in order to incorporate it into the revision of the regulation of electricity grids.

In its report, REE, chaired by Beatriz Corredor, stated that as long as the generation that provides stability and inertia to the system - provided by hydroelectric, combined cycle and nuclear power plants - remained "sufficient", no changes were expected. But she warned that "in the future" and in areas with a high penetration of generation based on power electronics - such as photovoltaics - "there could be situations in which the behaviour of some of the current protection functions would not be as expected".

In order to remedy these shortcomings, REE proposed that the application period for the new protection mechanisms was five years from the approval of the procedures, "if necessary". It stated that there was no immediate need to apply the measures. Likewise, the manager highlighted the need to update the 1996 action protocol to resolve the different disturbances that the electricity system could suffer, as it had become obsolete and urged that it be changed to adapt it to current technologies.

The operating principles of current protection systems are designed for an electrical system in which most generation comes from conventional sources - thermal, nuclear, and hydro - primarily consisting of synchronous generators. In these cases, the behavior of the protection systems meets the reliability criteria necessary to ensure network safety and continuity of supply at all times in the event of any type of fault, as they have been designed to operate in these generation scenarios, with the response of the generating units to short circuits being well understood," the proposal read.

According to the ministry, the operator's proposal was subject to public consultation and was received by the department on 24 January. "Miteco has been working with it to integrate it into the revision of the electricity network regulation, which includes the revision of the investment limits in relation to GDP and other provisions with a view to maximising the benefits of the next electricity planning 2030 horizon."

After the power cut, all eyes turned to the renewables sector, specifically on photovoltaic solar energy, as well as on the role of REE, despite the fact that the president Pedro Sánchez said that all responsibility should fall on private operators.

It was not the only warning. The European Network of Transmission System Operators for Electricity (ENTSO-E) also issued a warning about the growing risks of electricity surpluses in the continental electricity system during April and May 11 days before the blackout, "following an unusual coincidence of factors: an unusually sunny spring and a seasonal drop in energy demand".