30 Apr Darkness over Iberia
On April 28, 2025, Spain and Portugal suffered one of the most significant grid failures in modern European history. More than 55 million people were affected, and essential infrastructure including transport, telecommunications, and healthcare systems experienced critical disruptions.
Within seconds, Spain lost ~15 GW of generation capacity, causing grid frequency to plunge from the standard 50 Hz to 49 Hz. This triggered automatic protective shutdowns across power stations and transmission lines.
Renewables supply about 80% of electricity in Iberia. The grid lacked sufficient inertia and dispatchable backup to respond to the sharp frequency deviation, exacerbating the instability.
Portugal, highly dependent on imports from Spain, was quickly drawn into the cascade failure. Both countries lacked adequate grid-forming inverters, battery storage, and flexible backup generation to absorb the shock.
A critical high-voltage interconnector between Spain and France failed, eliminating external support to stabilize frequency.
Extreme inland heat created oscillations in long-distance transmission lines—a rare but real phenomenon that may have helped trigger desynchronization. There were at least five deaths, including individuals dependent on medical devices and others caught in fire incidents. There were estimated losses of €2.25 to €4.5 billion, impacting industries like manufacturing, logistics, and food processing. Trains, airports, and metros halted mid-operation; border systems failed. Cell towers, ATMs, and emergency communication systems went down in large areas rendering emergency services virtually useless.
A moderate share of nuclear in the energy mix could have significantly mitigated or even prevented the blackout because nuclear plants provide inertial stability. Their massive turbines contribute rotating mass to the grid, helping maintain frequency. They also run continuously, providing consistent output that doesn’t fluctuate with weather and nuclear power stations are resistant to cascading shutdowns that affect lighter, less stable generation sources.
What Percentage of Nuclear Would Help? To estimate a stabilizing nuclear share, consider the following:
Spain and Portugal consume ~300 TWh/year of electricity. To counteract a 15 GW instantaneous loss, the system needs at least 10–12 GW of stable, inertia-providing capacity available at all times. A nuclear share of 20–25% of total generation (~60–75 TWh/year) equivalent to 7–9 GW of operational nuclear capacity would likely have maintained grid stability or at least greatly slowed the collapse, giving operators time to intervene.
France (which avoided cascade effects despite being linked) has ~63 GW of nuclear providing ~70% of electricity. Its grid is notably more stable due to this consistent baseload.
The blackout highlights the fragility of high-renewable systems without adequate grid stabilizers. While renewables are essential for decarbonization, they must be complemented by reliable, dispatchable generation. Spain and Portugal should aim for at least 20–25% nuclear share to ensure resilience.
This should be a wakeup call to Australians who think they can achieve net zero in 2050 with 213 GW of wind and solar backed up by 22 GW of gas. There is no help from next door in Australia. We need a nuclear strategy and we need it before our coal fired backup is decommissioned.
David Wilson
Posted at 05:35h, 02 MayThe Iberian Blackout: A Wake-Up Call Australia Can’t Ignore
On a sunny spring afternoon in late April, the Iberian Peninsula was plunged into darkness. A massive blackout struck Spain and Portugal, disrupting transportation, communications, hospitals, and homes. In a matter of minutes, tens of millions were affected by the collapse of a grid system long regarded as modern and robust.
Initial reports suggest the cascade began in southwestern Spain, where a sudden drop in solar output — possibly due to fast-moving cloud cover or inverter failure — triggered a chain reaction of power loss. While investigations are ongoing, what is already clear is this: even advanced, renewables-rich grids are vulnerable without adequate backup and stabilising infrastructure.
European Countries Can Fall Back on Its Neighbours
For all the chaos, Europe had one crucial advantage: interconnectedness. The European grid is among the most integrated in the world, allowing countries to import and export electricity across borders. When Portugal’s western grid began to wobble, support from Spain’s interior — and beyond — helped stabilise the system. Within hours, backup from neighbouring grids helped restore service to key areas.
Australia Can’t
Australia, by contrast, is an energy island. We have no neighbouring nations to draw emergency power from in the event of a large-scale grid failure. Our east coast National Electricity Market (NEM) stretches thousands of kilometres but is bounded by ocean. If something goes wrong — a line trip, a generator collapse, a frequency drop — there is no continental backup. We are on our own. This makes the Iberian blackout an especially stark warning for us.
The Risks of an Unbalanced Transition
Australia’s transition to renewable energy is underway, with rapid growth in solar and wind generation. But this transition has often been pursued with insufficient attention to the need for firming and backup capacity. As more coal and gas plants are retired, the grid’s resilience is increasingly reliant on variable renewable output — often in the absence of large-scale storage, fast-start generation, or grid inertia. The Iberian event shows how quickly things can unravel when intermittent power sources are not properly buffered.
What Needs to Be Done
Battery systems, synchronous condensers, and advanced control technologies can help maintain frequency and voltage when renewables dominate. Gas is filling some of the gap, but Australia must consider all zero-emission options — including nuclear — to ensure secure, on-demand power. Pumped hydro, hydrogen, and thermal storage systems are needed to cover renewable lulls lasting hours or days.
Unlike Europe, Australia must build redundancy into its grid as if help will never come — because it won’t. Connecting renewable-rich regions to demand centres requires new transmission corridors and digitalised grid control.
Time to Get Serious
The Iberian blackout is more than a foreign incident — it is a mirror. Australia must take a sober look at its energy future. We cannot copy Europe’s path wholesale because we lack its geographical advantages. If we are to lead on clean energy, we must also lead on energy resilience. And that means building a system that can stand alone — because in the moment of crisis, it will have to.
The lights went out in Lisbon and Madrid and five people on life support died. Let’s make sure they don’t go out in Sydney and Melbourne.