How a 0.2Hz Wave Took Down Two Countries’ Power Grids
🔌 How did a slow 0.2Hz wave trigger one of Europe’s biggest blackouts? On April 28, 2025, the Iberian power grid—spanning Spain and Portugal—collapsed in under 90 seconds. In this video, I explain exactly what went wrong, why it wasn’t a “renewables problem,” and how it could happen again.
As a grid engineer, I break down:
The five cascading phases of the blackout
Why low demand and excess reactive power primed the system for failure
What inter-area oscillations are (and why they’re so dangerous)
How protection relays and poor ride-through settings accelerated collapse
What went wrong with voltage control and shared infrastructure
The roles of France, Morocco, and Portugal in restarting the grid
What this means for the future of high-renewables grids like the UK
Spoiler: Renewables weren't the root cause, but poor integration and weak grid planning were.
📈 Whether you're an energy nerd, an engineer, or just curious how a wave can take down two countries' power, this video dives deep with expert insight and real data from official blackout reports by ENTSO-E, REE, and AELEC.
🔧 Chapters:
0:00 Intro
1:12 Phase Zero, Why
5:35 Phase 1, Inter-Area Oscillations
10:30 Overvoltage Protection and Ride Through
12:00 SCADA
12:40 RoCoF & Callide C4
13:26 Phase 3, Cascading Collapse
15: 20 Transformer Taps
16:40 Root Causes
18:35 New Report Issued
19:20 Energy Storage
19:30 Phase 4, System Black
21:48 Lessons and Fixes
23:55 Can this happen to the UK
26:35 Outro
27:05 Out-Takes
Corrections:
1:49 Heaters are a resistive load, not reactive generally.
15:35 I wrongly point at the LV side. Tap changers are typically on the HV side (taller side) however either side can be the primary or secondary depending on context. In a step up transformer the LV side would be primary.
🔗 Sources
📄 ENTSO-E Investigation: [https://www.entsoe.eu/publications/bl...]
📄 REE Report: [https://wattclarity.com.au/articles/2...]
📄 Spanish Gov Report: [https://www.lamoncloa.gob.es/consejod...]
📄 AELEC Full Report: [https://aelec.es/wp-content/uploads/2...]
📄 UK 2019 Blackout Reference: [ • How to Restart the Grid after total collapse ]
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#IberianBlackout #GridCollapse #PowerSystems #EngineeringExplained #Renewables #SpainBlackout #ENTSOE #EnergyTransition