The basics
So what is electricity exactly? Usually, we’re talking about different things at the same time.
Naturally occurring electricity is called electrical charge. It is a fundamental property of matter, carried by several elementary particles.
Generated electricity is electrical or electromagnetic energy. It flows at almost the speed of light and is measured in Watts. A source such as a battery or generator putsit into a circuit, where a “load” such as alight bulb consumes it and so removes it from the circuit.
Electric power
Electric current refers to electrons flowing along a wire or other conductor. The rate of this flow is measured in amperes (A), and is based on the number of electrons flowing past a given point in a second.
The force that drives the electrons in the wire is called the voltage. It is similar to the pressure that drives water in a pipe and is measured in volts (V).
Electrical power is proportional to the voltage multiplied by the current.
The wire used to transmit the power does not allow all the current to pass through it unimpeded. There is a resistance, similar to friction, which causes the wires to heat and energy is lost.
Since the goal of transmission is to get a given amount of power from A to B, these losses have to be reduced. A law of physics states that as voltage is increased, proportionately less current is needed to transmit the same amount of power. Increasing the voltage by a factor of 10 reduces the current needed to transmit the same power by a factor of 10, and thus the energy lost to resistance is reduced by a factor of 100.
Key dates in history
600 BC Discovery of static electricity
1600 William Gilbert invented the term electricity
1750s Benjamin Franklin proved that lightning is a form of electricity
1800 Humphry Davy discovered Electrolysis
1820s Thomas Johann Seebeck discovered thermo electricity
1830s Michael Faraday establishes the principles of electricity and magnetism, known today as “field theory”
1870s Thomas Edison built a DC electric generator
1880s The first public electricity supply
1920s First National Grid was introduced in the UK
1950s First large-scale nuclear power station opened
2000 The world’s first commercial wave power station began to generate electricity