The main culprit behind a maintenance-bill 'bomb' — summer air-conditioning. What should you know about Korea's electricity pricing?

Korean household electricity billing uses a progressive tiered rate structure, meaning the price per unit of electricity increases as total monthly usage climbs into higher brackets, rather than charging a flat rate for every kilowatt-hour consumed. This is precisely why running an air conditioner heavily through a hot Korean summer can push a household from a cheap lower tier into a dramatically more expensive top tier, producing the feared 'electricity bomb' bill.

Neither of the other claims reflects real billing practice: nighttime electricity isn't free for ordinary households, and the government does not subsidize air-conditioner electricity specifically — both ignore how the tiered system actually calculates cost based on total usage.

The tiered structure was originally designed with energy conservation in mind, encouraging households to moderate consumption, which is why many people supplement AC with fans or adjust the thermostat by just a degree or two to avoid crossing into a pricier bracket.