How do generators generate electricity?

Answer 1

If a loop of wire is moved into a magnetic field, so that there is some magnetic flux linked through the loop when there was none before, a voltmeter will register a voltage generated in the loop while the flux is changing.

If a resistor is connected across the ends of the loop, current will flow in it and power will be generated while the flux is changing. Some force will now be needed to push the coil into the magnetic field, and that force, moved through a distance, represents energy that is used to heat the resistor. That is an elementary electric generator that converts mechanical power into electric power.

In a real electric generator (or motor) there are coils of wire and magnets. Either the coils or the magnets are on a rotating shaft. The principle is the same: a loop or coil of wire with a changing magnetic flux produces a voltage, and that voltage can heat a resistor, or supply some other electrical load, while mechanical power is needed to turn the shaft. If more electric power is drawn, more torque or speed will be needed to turn the shaft.

When you put an extra load on your house power supply, like a kettle for example, the generator in your local power plant will slow down very slightly until the governer asks for more steam from the boiler that is driving the turbo-generator. In that way a power plant's use of fuel is closely linked to the amount of energy it has to supply

Answer 2

Generators generate electricity by converting mechanical energy into electrical energy. This process typically involves a magnet moving past coils of wire, creating an electric current through electromagnetic induction. The rotation of the turbine or engine connected to the generator provides the mechanical energy needed to drive this process.