Is it true that Redeia warned about the risks of increasing the share of renewable energies in the energy mix?

Redeia, through its subsidiary Red Eléctrica de España (REE), has indeed issued warnings and concerns about the risks associated with increasing the share of renewable energies in the energy mix, particularly concerning grid stability. In 2020, internal studies by Red Eléctrica warned it was "essential" to increase storage capacity or interconnections to "ensure the operability" of the grid during the green transition, noting that widespread integration of renewables would have a greater impact on Spain's grid stability due to its limited interconnection capacity . They suggested "essential" measures to avoid "inadmissible" frequency mismatches, such as those that caused the April 28 blackout . More recently, in February, Redeia acknowledged to investors the "short-term risk" of "generation disconnections due to the high penetration of renewables," warning that this increased instability could impact electricity supply and the company's reputation . Redeia also stated that continuing to close conventional generation plants (coal, natural gas, nuclear) "implies a reduction in the firm power and balancing capacities of the electricity system, as well as its strength and inertia" . Furthermore, an internal document from May 2024, published by *El Periódico de la Energía*, revealed that REE had proposed updating the action plan to manage disturbances from the massive entry of renewables, noting that the current criteria protocol dated back to 1996 and was outdated . The report warned that in areas with high penetration of power electronics-based generation, like photovoltaics, "there could be situations in which the behaviour of some of the current protection functions would not be as expected" . This aligns with concerns raised by other experts, including Spain’s National Commission on Markets and Competition (CNMC) in January 2025, which noted that tensions within the transmission network had "reached maximum values close to the thresholds allowed by the regulations, even exceeding them at specific times" and predicted this could increase . The European Network of Transmission System Operators for Electricity (ENTSO-E) also warned Spain could face a heightened risk of blackouts between 2026 and 2028, coinciding with the planned closure of the Almaraz nuclear power plant . The secure integration of renewable energies is acknowledged as one of the main challenges for the operation of the electricity system in the ecological transition, entailing "enormous complexity" and "great challenges" that require large-scale solutions . However, other information from Redeia and related entities emphasizes the successful integration and benefits of renewable energy. Redeia's official stance, as presented by its chairwoman Beatriz Corredor, is that "Spain achieved its best-ever indicators in 2024, setting a double record in both renewable electricity generation and its share of the generation mix." She also stated that "we have positioned ourselves at the forefront of Europe’s energy transition" and that Spain has "integrated 98% of them reliably and securely into the system" . In 2024, Spain closed the year with 148,999 GWh of renewable energy generation, a 10.3% increase from the previous year, accounting for 56.8% of the total energy mix . Renewables supplied about 59% of Spain’s electricity in 2024 . By December 31, 2024, renewables made up 66% of Spain's total installed generation capacity of 129 GW . In 2024, Spain’s electricity system added 7.3 GW of new renewable capacity, primarily from solar photovoltaic and wind power, marking the largest annual increase ever recorded . Driven by this surge, CO2-equivalent emissions from electricity generation reached an all-time low in 2024 . Redeia also highlights its accelerating investment to bolster the transmission grid, with total investments amounting to €996.2 million in 2023, of which €825 million went to Red Eléctrica, marking a 55% increase from the previous year . These investments include progress in strategic cross-border connections with France and Portugal, "essential for the integration of renewables and energy autonomy," and investment in energy storage, such as the Salto de Chira hydroelectric power station . Red Eléctrica has also, for the first time, included energy storage metrics in its annual reports, covering technologies like batteries and pumped storage that "optimise renewable energy integration and enable energy to be fed back into the system" . Spain has an installed energy storage capacity of 3,356 MW . The European Cross-Border Intraday Market (XBID), launched by NEMOs and TSOs including Red Eléctrica, aims to balance the electricity system with the rising share of intermittent renewable technologies, enabling increased integration of more renewable generation and greater overall efficiency . There is also an argument that the April 28 blackout was not solely due to renewables but rather an outdated grid infrastructure and lack of battery storage systems . While the lack of inertia may have played a part, wind and solar power can generate synthetic inertia, and if Spain’s grid was backed up by more batteries, the blackout might have been prevented . Based on the available evidence, it is true that Redeia has warned about the risks of increasing the share of renewable energies in the energy mix. Redeia, through its subsidiary Red Eléctrica, has explicitly identified "short-term risk" of "generation disconnections due to the high penetration of renewables" to investors and has stated that the closure of conventional plants reduces the system's "strength and inertia" . Internal studies and proposed action plan updates also indicate awareness of potential failures and the need for updated protection criteria due to massive renewable integration . However, it is crucial to understand that these warnings are presented within a broader context where Redeia also actively promotes and reports record-breaking successful integration of renewables, viewing it as a key part of Spain's energy transition and investing significantly in grid infrastructure and storage to support it . The warnings appear to be calls for necessary grid modernization and investment to *manage* the challenges of high renewable penetration, rather than a blanket opposition to renewables themselves. The evidence suggests a recognition of the complexities and challenges inherent in this transition, alongside a strong commitment to achieving a high renewable energy share.