Blackout warning: Dense fog, pollution up risk of power lines tripping

There’s more to dense fog conditions than pollution and flight cancellations.

- Vijay C. Roy & Rituraj Baruah

There’s also the risk of power outages.In fact, a perfect storm may be brewing across several parts of north and central India, where a rain-deficient winter, dense fog conditions and atmospheric pollution have raised concerns over the tripping of power transmission lines, said three people aware of the outage concerns in India’s power system.

Fog increases moisture on power transmission lines, allowing pollutants in the air to settle on their surface. Over time, dust and grime accumulate on these lines, reducing insulation strength and leading to flashovers (a high-voltage discharge where electricity “jumps” across an unintended path—usually through the air or over the surface of an insulator), short circuits and automatic tripping of transmission and distribution lines.