Process — Electricity generated from coal

The diagram shows how a coal-fired power station converts coal into electricity in eight stages.

Overall, the process is a chain of energy conversions — burning coal produces heat, heat produces steam, steam produces rotation, and rotation produces electricity — supported by two secondary loops in which water is recycled to the boiler and waste gases are cleaned before release.

The process begins when coal is delivered from the mine and fed into a pulveriser, which grinds it into a fine powder so that it burns efficiently. This powder is then burned in a boiler, where the intense heat turns water in the pipes above the flames into high-pressure steam. The steam is piped to a turbine hall, where it spins a turbine connected to a generator, and the electricity generated is sent via pylons to the national grid.

Meanwhile, the used steam passes into a condenser, where it is cooled back into water; this water returns to the boiler in a closed loop, while excess heat escapes from a large cooling tower. Finally, the gases produced by burning the coal do not go straight into the air: they pass through filters in the chimney, which remove most of the pollutants before the cleaned gases are released.