knowledge base

How is electricity produced.

A characteristic of electricity is that it is not a primary energy freely present in nature in remarkable amounts and it must be produced. Production is carried out in power stations (also called “power plants”).

Most power plants/stations contain one or more generators, a rotating machine that converts mechanical power into electrical power. The relative motion between a magnetic field and a conductor creates an electrical current.

So the source can be different to move the generator:

• In hydro, water is used to move turbines
• In coal plants, steam does the job
• In wind power, the movement of those giant blades generates electricity.
• Or a nuclear reaction to produce steam.
• Or solar panels convert sunlight to electricity.
• Or geothermal energy to move turbines.
• Basically, any mechanical movement can be used to move the generator.

Frequency in electricity

How does frequency come about? As we know, electricity is produced by converting mechanical movement to electricity using the phenomenon of magnetism.

• So when a conductor rotates in a magnetic field, the magnetic field lines are cut and current is induced in the conductor.
• Since the magnet has lines of field from north to south (uni-directional), the conductor will move back and forth in this direction.
• So when it cuts all the lines, the maximum current is induced, and then as it moves back with no lines cut, the current is zero. Then the conductor comes back in the opposite direction, inducing a reverse current.

So this is like a sine wave: the current goes to a maximum, then zero, then a negative maximum (on the other side). We have rectifiers to manage this, but this is what frequency is in electric current.

Reference:

• https://en.wikipedia.org/wiki/Power_station
• https://en.wikipedia.org/wiki/Electricity_generation
• https://www.youtube.com/watch?v=4oRT7PoXSS0