The Spain Blackout: A Cautionary Tale of Solar Energy’s Limits and Net Zero Ambitions, By James Reed and Richard Miller (Londonistan)
The catastrophic blackout that struck Spain and Portugal on April 28, 2025, affecting over 60 million people, has sparked intense debate about the reliability of renewable energy, particularly solar power, in the context of aggressive Net Zero policies. An official Spanish government investigation, as reported by The Daily Sceptic and The Telegraph, concluded that the blackout was triggered by solar farms switching off due to negative power prices caused by an oversupply of solar energy. Despite this, Spain's Left-wing government has downplayed the role of renewables, raising questions about the security of solar-dependent grids and the broader implications for countries like the UK pursuing ambitious decarbonisation goals. We examine the causes of the blackout, the vulnerabilities of solar power highlighted by the event, and why the lessons of this disaster seem to be ignored in the mistaken rush toward Net Zero.
On April 28, 2025, at approximately 12:33 CEST, a massive power outage swept across the Iberian Peninsula, plunging Spain, Portugal, and parts of southwestern France and Andorra into darkness for up to 18 hours. The blackout disrupted telecommunications, transportation, and essential services, grounding flights, halting trains, and trapping people in elevators. At least eight deaths were linked to outage-related incidents, such as candle fires and generator misuse.
According to the Spanish government's investigation, the blackout was triggered by a cascade of events originating in the southwest region of Extremadura, home to significant solar farms, hydroelectric facilities, and the Almaraz Nuclear Power Plant. Solar power, accounting for 59% of Spain's electricity at the time, was the dominant energy source, with wind at 12%, nuclear at 11%, and gas at 5%. The report found that on this particularly sunny day, solar farms generated so much power that electricity prices in Spain's spot market plummeted to negative values, meaning operators were essentially paying to offload energy.
This oversupply led to a mass switch-off of solar farms, as it became unprofitable to continue operations. The sudden disconnection of thousands of solar facilities, dropping solar generation from 18,000 MW to 8,000 MW in seconds, caused voltage and frequency fluctuations across the grid. These fluctuations destabilized the system, leading to the disconnection of the Spain-France interconnector and the automatic shutdown of nuclear and other power plants as safety protocols kicked in. The grid operator, Red Eléctrica de España (REE), failed to manage these fluctuations, as backup systems meant to stabilise the grid were not in effect.
The Spain blackout highlights several inherent vulnerabilities in solar power and grids heavily reliant on renewables:
1.Lack of Inertia: Unlike traditional power sources like gas, nuclear, or hydroelectric plants, which provide grid stability through the inertia of spinning turbines, solar photovoltaic systems generate direct current (DC) and rely on inverters to convert it to alternating current (AC) at the standard 50 Hz frequency. These "grid-following" inverters do not provide inertia, meaning they cannot buffer sudden frequency drops, making the grid more susceptible to instability during disruptions. The high penetration of solar power (59% at the time of the blackout) exacerbated this issue, as the grid lacked sufficient stable baseload power from nuclear or gas.
2.Negative Pricing and Economic Incentives: The oversupply of solar power drove electricity prices to negative levels, a phenomenon increasingly common in renewable-heavy grids. In Spain, prices fell from €145 per megawatt-hour in January to €11 by March, and on April 28, they turned negative. This economic disincentive prompted solar operators to curtail production, triggering the mass switch-off that destabilised the grid. The reliance on market-driven decisions in a profit-oriented energy system, nothing wrong with that, amplified the crisis, as operators prioritised financial viability over grid stability, as they should.
3.Grid Management Failures: The Spanish grid operator, REE, was criticised for poor management and inadequate preparation for the rapid integration of renewables. A 2024 REE report had warned that "the high penetration of renewable generation without the necessary technical capacity to deal adequately with disturbances" could lead to blackouts, yet insufficient investments in grid-forming inverters, battery storage, or synchronous condensers left the system vulnerable. The disconnection of solar plants was a consequence of frequency disturbances, not the cause, but the grid's inability to handle these events exposed systemic weaknesses.
4.Limited Interconnectivity: Spain's grid is relatively isolated, with only 5% of its power capacity connected to external grids like France and Morocco, compared to the EU's 15% interconnection target by 2030. When the Spain-France interconnector tripped during the blackout, Spain could not quickly import stabilising power, worsening the crisis. This isolation contrasts with countries like Denmark and Germany, which manage high renewable penetration through robust interconnections and advanced grid management.
Despite the investigation's findings, Spain's Left-wing government, led by Prime Minister Pedro Sánchez, has vehemently denied that renewable energy was to blame. Environment Minister Sara Aagesen argued that the grid had operated reliably with similar energy mixes in the past, and REE's president, Beatriz Corredor, insisted that renewables are "stable" and equipped to function like conventional systems. Sánchez dismissed claims linking the blackout to renewables as "lies," accusing critics of spreading disinformation.
This stance has fuelled a political blame game. Opposition leader Alberto Núñez Feijóo of the People's Party accused the government of choosing green ideology over grid reliability, stating that ministers' obsession with being "the greenest in the world" had "led Spaniards into the dark." Critics, including energy experts and conservative commentators, argue that the blackout validates warnings about the risks of over-reliance on intermittent renewables without adequate backup systems. Posts on X echoed this sentiment, with users like @BjornLomborg and @digijordan highlighting the irony of Spain's blackout occurring days after it celebrated running entirely on renewables on April 16.
However, defenders of renewables, such as Fundación Renovables and SolarPower Europe, argue that solar and wind were not the root cause but rather victims of a frequency disturbance that triggered automatic disconnections as per safety protocols. They claim that renewables, particularly hydropower, aided Spain's rapid grid recovery, and that rooftop solar with storage could enhance resilience during outages. These groups call for better grid management and investments in storage and interconnectivity rather than scapegoating renewables; but they are mistaken.
The Spain blackout serves as a cautionary tale for countries like the UK (and Australia), where Energy Secretary Ed Miliband aims to decarbonise the energy system by 2030, relying heavily on wind, solar, and nuclear. The UK's National Energy System Operator claims its grid is more resilient due to investments in voltage control and inertia-measuring systems, but the Spanish case underscores the need for substantial grid upgrades to handle high renewable penetration. The European Commission estimates that Europe needs $2.0–2.3 trillion by 2050 to modernise its aging grids, a scale of investment that has lagged behind renewable deployment.
The blackout also highlights the economic absurdities of Net Zero. Negative pricing, as seen in Spain, discourages stable baseload sources like nuclear, which struggled to cover taxes during low-price periods, leading to temporary shutdowns before the blackout. This dynamic threatens the viability of conventional power plants, which are critical for grid stability, and underscores the need for market reforms to incentivise backup capacity and storage.
Despite the clear vulnerabilities exposed by the blackout, Spain's government and Net Zero advocates continue to downplay the role of renewables, driven by a mix of ideological commitment and political pressures. The Sánchez administration's investment in renewables is a cornerstone of its identity, and admitting systemic flaws could undermine its ecological transition narrative. Similarly, the EU's energy roadmap, which endorses Spain's plan to phase out nuclear power by 2035, reflects a broader ideological bias toward renewables, even at the cost of grid stability.
Sceptics argue that this denial ignores the physics of grid management, as highlighted by posts on X criticising Spain's "enormous ideological bias" in energy policy. The failure to invest in grid-forming inverters, battery storage, and stronger interconnectors, combined with the rapid phase-out of nuclear power, creates a recipe for future outages. Yet, the political cost of acknowledging these limits may be too high for governments wedded to Net Zero timelines, especially when public support for renewables remains strong despite concerns about reliability.
In conclusion the Spain blackout of April 2025 was a stark reminder of the limits and insecurities of solar power in renewable-heavy grids. The mass switch-off of solar farms due to negative pricing, coupled with inadequate grid management and limited inertia, triggered a catastrophic cascade that exposed systemic vulnerabilities. While Spain's government insists that renewables were not at fault, the evidence suggests that their rapid integration without corresponding infrastructure upgrades played a significant role. For countries like the UK and Australia pursuing Net Zero, the lesson is clear: decarbonisation must be paired with massive investments in grid resilience, storage, and stable baseload power to avoid plunging into the dark. Or, the climate change myth rejected, a better option. Ignoring these realities in favour of ideological purity risks repeating Spain's costly mistake.
"Spain's disastrous national blackout in April was triggered by solar farms switching off in response to plummeting power prices, an official investigation has found. The Telegraph has more.
A Government report into Europe's biggest power cut found that Spain's solar farms were generating so much power on April 28th, a particularly sunny day, that prices became "negative" – meaning there were no profits to be made in operating them.
Plunging prices triggered a mass switch-off, which sent voltage and frequency fluctuations cascading across the national grids of both Spain and Portugal. Back-up systems meant to guard against such fluctuations were not in effect.
This caused blackouts that left more than 60 million people across the Iberian peninsula without power, the Spanish Government report concluded.
The power cut caused massive gridlock in cities and left thousands stranded on trains and in elevators across the Iberian peninsula. Several deaths were also linked to the incident.
Experts said in the immediate aftermath of the power cut that a reliance on Net Zero energy had left Spain and Portugal vulnerable to the blackouts because of the way renewable power is generated. However, Spain's Left-wing Government has repeatedly insisted that green energy was not to blame.
Alberto Núñez Feijóo, leader of the opposition People's Party (PP), said ministers were "so intent on being the greenest in the world that you have led Spaniards into the dark", the BBC reported.
The investigation's findings will fuel concerns about Britain's race to Net Zero, led by Ed Miliband, the Energy Secretary. Mr Miliband wants to make Britain's energy system carbon free by 2030, a shift that will see the country rely almost entirely on renewable energy, such as wind, solar and nuclear to keep the lights on."
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