Coal is a great example of stored chemical energy.
The illustration below shows how chemical energy in coal is tapped to produce electricity.

Coal stored in a reservoir is fed into a bunker (boiler). Here, it is burned at extremely high temperatures.

Burning releases the chemical energy in the coal in the form of extreme heat (thermal energy).

The extreme heat produced by the burning coal is used to heat water in tanks to produce steam.

The steam is directed through special tubes connected to shafts.

A shaft is like a machine with blades that can turn like the blades of a fan.

The spinning shafts are connected to a generator that generates electricity from the process.