4. ELECTRICAL ENERGY

4. ELECTRICAL ENERGY.

Electrical energy is a form of energy that is transported by an electrical current.
Electrical energy is the most commonly used energy in modern, industrialised societies. There are many technological objects around us that use electricity.

Electricity is very common for two reasons:

• It can be easily transformed into other types of energy, such as light and heat.
• It can be transported over long distances in ways that are cheap and efficient.

4.1. Electric power stations.

A power station or generating station is a place where energy from natural resources is transformed into energy that we can consume. If the energy obtained is electricity, it is called an electric power station.

How electricity is generated.
Electric power stations require sources of energy, such as the mechanical energy of falling water. They use generators to transform this energy into electricity.
The electric generators used in power stations are called alternators.
An alternator usually has a stationary part, called a stator, and a moving part, called a rotor.
The turbine-alternator system is used at all power stations except for photovoltaic stations, which use a different type of technology.

4.2. The transportation and distribution of electricity.

Electric energy cannot be stored. As a result, it must be transported from power stations to the places where it is needed, such as industries and urban areas.

The transportation of electrical energy includes:

• Raising the voltage: Electricity must be transported over long distances, so the oltage is raised to avoid the loss of energy as heat.
• High voltage lines: Routes for high voltage lines are carefully planned and the lines are installed on toers.
• Reducing the voltage: Electrical substations are installed between high voltage lines and final consumers.
• The power is distributed to homes, offices, industries and public installations, such as streetlights and traffic lights. The electric lines are usually supported by posts or installed underground.