LessWrong (Curated & Popular) "Solar storms" by Croissanthology
Mar 9, 2026
Long-distance power lines snake across continents and create surprising vulnerabilities. The podcast examines how high-voltage transformers and bespoke transmission infrastructure work. It explains how solar storms and geomagnetically induced currents can saturate and destroy large transformers. It reviews real-world cases, national preparations, and the economic and political hurdles to protecting the grid.
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Transformers Are Rare Bespoke Giants
- Large power transformers (LPTs) are bespoke, heavy, artisanal machines that take 2–4 years to build and weigh 200–400 tons.
- Each LPT is custom to grid specs, transported on special rail cars, and Earth produces <1000 per year, limiting rapid replacement.
Solar Storms Turn Earth's Magnetic Field Into A Current Source
- A Carrington-scale CME mainly threatens us via its magnetic field linking with Earth's, exciting electrojets that induce continent-scale shifting magnetic fields.
- Those shifting fields drive GICs through grounded long transmission lines into transformers as quasi-DC currents.
DC Pollution Destroys Transformer Cores Fast
- Even small DC offsets from GICs push transformer cores into half-cycle saturation, leaving coils uncontrolled and producing chaotic magnetic forces and heat.
- Saturation triggers micro-arcing, paper baking, and rapid irreversible damage inside the oil-paper-wound LPT.
