Almost all of them boil water
How Does a Power Station Work?
Coal, gas and nuclear stations look completely different and all do the same thing: heat water until the steam spins something.
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Step 1 of 5
The fuel is only there to make heat.
Coal, gas and nuclear fuel have nothing in common except that each releases a lot of heat. Everything after that point in the station is identical, which is why one can be swapped for another.
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Step 2 of 5
Steam pushes very hard.
Water turns to steam and takes up over a thousand times more room. Trapped in a boiler, that expansion becomes an enormous push — and pushing is what a turbine needs.
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Step 3 of 5
A turbine is a windmill for steam.
The steam is aimed at rings of angled blades on a shaft. Each ring takes a little energy out and the shaft spins fast — often fifty turns every second, without stopping for months.
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Step 4 of 5
Spinning a magnet near wire makes electricity.
The shaft turns a magnet inside coils of wire. A moving magnet pushes the electrons in the wire along, and that push is the electricity that leaves the building.
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Step 5 of 5
Most of the fuel's energy is wasted.
Only a third or so of the heat ends up as electricity; the rest goes up the cooling towers as warm air and water. That is not bad engineering — it is a hard limit on any engine driven by heat.
Solar panels and wind turbines skip the boiling entirely, which is why neither has a cooling tower.
The short version
A power station burns or splits fuel to boil water; the steam spins a turbine, and the turbine spins a magnet inside coils of wire.
Try it yourself
Hold a lid over a boiling pan. The push you feel lifting it is the same push that drives a turbine, in miniature.
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