06 August 2026
One year on: What the Iberian blackout really taught us about the energy transition
By: Isaline Court, Data Analyst at BFF
April 28, 2025 plunged Spain and Portugal into darkness. A year later, the evidence is in, and it debunks what renewables critics wrongly predicted.
In April 2025, Spain and Portugal suffered a total blackout, the most severe in Europe in over 20 years. It took 12 hours to fully restore power in Portugal and 16 in Spain. Transport collapsed. Telecoms failed. Industries ground to a halt. Citizens were left in the dark in the most literal sense.
And within hours, before the lights had even come back on, several media outlets had already found their culprit: renewable energy.
They were wrong. ENTSO-E’s final report concluded that the blackout resulted from multiple interacting factors in power system operation, specifically “voltage fluctuations and oscillatory phenomena.” Renewables were not the cause. IEEFA’s independent analysis reached the same conclusion.
Now, one year later, what have Spain and Portugal done to fortify their energy systems for the future and make sure a blackout doesn’t happen again?
Renewables kept growing and saving money
Despite the initial blame game, Spain and Portugal did not flinch on their renewable commitments. In fact, Spain went all in. In 2025, it added 14 GW of solar capacity, the highest yearly increase ever, and 2026 has started even stronger. And that proved to be a smart decision.
When the war on Iran sent gas and electricity prices soaring again, with the cost of gas-fired electricity generation in Europe almost doubling between March 2024 and March 2025, Spain and Portugal were significantly more shielded than their European neighbours. Their renewable buildout had broken the link between gas prices and electricity prices.
Spanish households have saved €10 per month on their electricity bills since the current energy crisis began in March, thanks to renewables installed since 2021. The sensitivity of Iberian electricity prices to gas price shocks fell by 53% between 2022 and 2025, making Spain and Portugal the third least sensitive countries in the EU. Gas set the electricity price in just 9% of hours in Spain in the first four months of 2026, down from 55% in 2022.
In each of the first four months of 2026, Spain and Portugal ranked among the three EU countries with the lowest wholesale power prices. Spain’s wholesale electricity prices are now around three times lower than Italy’s, a country that remains heavily dependent on gas-fired generation.
The Iberian Peninsula had become, in the space of a year, one of the strongest pieces of evidence in Europe that the renewable transition works. As well as protecting people and the planet from climate collapse, it shields consumers from energy security and price shocks.
TSOs’ misguided response
Following the blackout, REE, the Spanish transmission system operator, came under intense political and public pressure to prevent recurrence. Its response was to implement what became known as a “reinforced procedure”: increasing the dispatch of gas-fired plants to enhance system stability, while curtailing more wind and solar generation. REN, the Portuguese TSO, simultaneously reduced electricity imports from Spain, also citing safety concerns.
What began as a temporary emergency measure became entrenched.
Comparing the twelve months before and after the blackout, Spain’s gas-fired generation increased by 8 TWh (+18%), while Portugal’s rose by 3.4 TWh (+65%), although part of it is linked to weaker hydro and wind generation. Iberdrola reported a 54% increase in the use of its combined-cycle gas turbines in Spain, directly associating it with REE’s anti-blackout plan.
The carbon intensity of electricity generation rebounded: up 5% year-on-year in Spain, up 16% in Portugal. Additional gas use cost Spanish consumers at least €0.4 billion in higher electricity prices in 2025, and potentially up to €1.5 billion.
In June 2026, the European Commission intervened directly, calling on Spain to move away from using fossil gas plants to stabilise its electricity system and arguing that grids, interconnections and storage should replace the emergency measures.
Three structural responses that point the right way
The blackout was a wake-up call about the need to future-proof the infrastructure required to operate a clean power system with high renewable shares safely and efficiently. Three responses stand out as genuinely constructive.
- Renewables are finally allowed to stabilise the grid, replacing gas
Following concerns about voltage fluctuations, Spain’s regulator (CNMC) required renewable plants to help contribute to voltage control services. Since March 2026, 32 solar plants and 17 wind farms have been approved to provide this support. The Spanish Photovoltaic Union (UNEF) has recommended that all large renewable plants should be enabled, reducing the need for gas-fired plants to keep the grid stable.
- Battery storage is gaining political momentum, but needs to move faster
With over 50 GW of installed solar capacity, Spain ranks second in Europe for solar deployment. When TSOs increased gas generation in response to the blackout, renewable curtailment more than doubled. With virtually no battery capacity to store surplus solar and wind power, Spain simply lets much of that clean electricity go to waste.
Germany, by comparison, has 15 GW of batteries, equivalent to 14% of its solar capacity. Italy has 8 GW, equivalent to 17%. Spain has a significant storage gap, and so does Portugal.
The blackout made this gap impossible to ignore. Both countries have now announced plans to address it.
Portugal has committed €400 million for grid management and battery storage and launched an auction in June 2026 for 750 MW of grid-scale batteries. It now aims for 2 GW of battery capacity by 2030, equivalent to roughly 10% of its solar target. Spain’s National Energy and Climate Plan includes a storage target of 22.5 GW by 2030, one of the most ambitious in Europe, according to SolarPower Europe.
But Spain has not yet held any battery auctions, and the timeline and conditions for a capacity market remain unclear. As BFF’s latest report on capacity mechanisms argues, a well-designed capacity market could boost battery deployment significantly, but poorly or biased capacity market designed one could lock in fossil gas instead.
- Interconnections: a longer-term fix that cannot wait
The blackout also exposed the vulnerability of an electricity system that remains insufficiently connected to the rest of Europe. With only a 2% cross-border interconnection capacity ratio, the Iberian Peninsula remains far from the EU’s interconnection targets of 10% by 2020 and 15% by 2030. Stronger cross-border connections would reduce the need for domestic gas backup and provide a safety net in the event of future system disruptions. Both countries have reinforced the case for the long-planned expansion of Iberian interconnections, but interconnections are long-term projects that take time to materialise, and require forward planning.
The Iberian story contains a lesson for Europe that cuts both ways
The Iberian Peninsula has demonstrated more clearly than almost anywhere else in Europe that high renewable penetration cuts electricity prices, reduces fossil import dependency, and protects consumers from gas market volatility. The energy crisis that has gripped the rest of Europe since 2022 has been markedly less severe in Spain and Portugal because of the investment decisions made in the preceding years.
Meanwhile, the governments and TSOs initial response to the blackout, i.e. burning more fossil gas, curtailing more renewables, considering extending the life of ageing gas infrastructure, shows how quickly hard-won progress towards a clean energy transition can be undone.
The blackout served as a stark wake-up call for Europe: even highly resilient electric systems are not immune to major disruptions. And the answer to a complex system event is not more fossil gas. It is better grids, more storage, stronger interconnections, and letting renewables do the grid service jobs they are already technically capable of doing.