Conductors and insulators

Electrical charge can flow through some materials, but not through others. Electrical conductors are materials which do allow electrical charge to flow freely through them. They conduct electricity. Electrical insulators are materials that do not allow electrical charge to flow freely through them.

Some examples of conductors are:

• Copper
• Aluminium
• Gold
• Silver

Some examples of insulators are:

• Glass
• Plastic
• Rubber
• Wood

Generating electricity

Electricity can be generated in lots of different ways. There are non-renewable and renewable methods of generating electricity. Fossil fuels (such as coal, oil or natural gas) and nuclear power are non-renewable. Non-renewable sources of power will eventually run out. Renewable sources of power will last forever. They include:

• Solar power
• Wind power
• Hydro-electric power
• Geothermal power

The method of electricity generation will vary depending on the source.

• For non-renewable energy, the burning of the fuel source (e.g. coal, oil or natural gas) produces heat which is used to boil water to create steam. This steam is used to spin turbines which creates electricity. 
• Nuclear power plants use the heat generated by fission in the nuclear reactor's core to produce the steam used to spin the electricity-generating turbines.
• Solar panels are made out photovoltaic cells which convert energy from the sun into electricity. 
• Wind turns the blades of wind turbines around a rotor which is connected to a generator. This movement creates electricity.
• Hydro-electric power is generated through the power of flowing water moving turbines to produce electricity.
• Geothermal energy uses steam to produce electricity. Unlike non-renewable energy production, the steam used in geothermal energy production comes from underground reservoirs of hot water and steam that are heated by the earth's internal heat.

The electrical current generated in a power station is sent along wires. Pylons carry these wires overhead, then underground wires carry the electricity into our homes.

Electricity: Electric Currents and Voltage

An electrical current is the steady flow of electrons. This is measured in amperes (amps). If you want to see which items in your homes use electrical currents or which item uses the most electricity then you can look at the number of amps the item uses. 
 

What is the voltage?

Voltage is the force that makes the electric current flow. This is measured in volts (V). The greater the voltage, the more current will flow. In most electric circuits batteries are the sources of voltage and therefore begin the steady flow of electrons.

Electricity: What Is a Circuit?

An electrical circuit can be complete or incomplete. Every complete circuit must have a power supply. The power supply could be the mains or a battery.

Current electricity is the flow of electrical charge through materials. For a circuit to be complete, there must be wires connected to both the positive and negative ends of the power supply. Current electricity can only flow around a complete circuit that has no gaps.