Electricity substations

SubstationsSubstations are an important part of the national grid. They contain transformers which increase or decrease the voltage of an electric current. Substations are very dangerous if you try to tamper with them or vandalise them. Do not enter a substation for any reason - it is against the law and you could be electrocuted. contain devices called transformersA transformer is a device that can change the voltage associated with an electric current. One type of transformer decreases the voltage and so is called a 'step-down' transformer. A 'step up' transformer increases the voltage.. A transformer is a device used to increase or decrease voltage of electric currentElectric current is a flow of electric charges (electrons). fed into it.

Large substations

Large substation

Electric current is generated with a voltage of 25,000 volts. A large substation like this one will increase the voltage to 132,000 or 400,000 volts ready for transmission across long distances. These large substations are also known as 'grid' substations.

The high voltage electric current usually leaves the grid substation on overhead linesThick electric cables that carry electricity from where it is generated to where it is used. carried high in the air on metal pylonsA tall metal tower that carries very high voltage overhead lines. - out of reach of people.

Pylon insulator

The overhead lines are fixed to the pylon with special insulatorsA material that reduces or stops the flow of electricity. made of glass and ceramics - to make sure the electric current doesn't travel down the pylon to the ground.

Small substations

Brick substation

On the way across the countryside, smaller substations step down the voltage to 33,000 volts for use by some factories and to supply power for trains.

Electric current generated by wind farms is usually fed into the distribution network at a lower voltage than fossil fuelCoal, oil and gas are called fossil fuels because they were formed from the remains of prehistoric plants and animals., nuclear or hydroelectric plants.

Small substation

Near to places like towns and cities, the voltage is stepped down to somewhere between 11,000 and 33,000 volts for use in factories.

Pole mounted transformers

Wooden pole substation

This wooden pole has a small transformer which steps the voltage down to between 230 and 450 volts for use by hospitals, factories and homes.

Did you know?

An electric eel can produce powerful electric shocks: up to 500 volts and one ampere of current (in other words, 500 watts).
In 1831 Michael Faraday demonstrated electromagnetic force at the the Royal Institution in London, a famous centre for scientific education and research.
The Italian inventor Alessandro Volta (1745-1827) is best known for his work on electric current.
In 1800 Alessandro Volta built the world's first battery from discs of copper and zinc sandwiched between cardboard moistened with a salty water.
In 1771 Luigi Galvani used electricity to make a dead frog's leg jump!
The ampere is named after André-Marie Ampère (1775-1836). He discovered many of the mathematical principles of electromagnetism.
Modern power stations and steam turbines use the same engineering principles that James Watt (1736-1819) applied when he invented the steam engine.
Save energy - Boil just enough water for the number of hot drinks you want to make - that way you won't waste energy.
Electricity used at home is metered in 'units' or kilowatt hours (kWh). Each unit is the same as 1,000 watts of electricity used for 1 hour. 1 unit = 1kWh.
Today we still use words that Benjamin Franklin (1706-1790) introduced: battery, conductor, positive and negative charge, electric shock and electrician.
Benjamin Franklin (1706-1790) developed the first lightning conductor after flying a kite in a thunderstorm. A spectacular but very dangerous experiment!
At Deptford in 1891, electrical engineer Sebastian Ziani de Ferranti (1864-1930) designed and built the first power station and supply network. His basic system is still used around the world.
In August 1887 the London Electric Supply Corporation commissioned Ferranti to build the first power station. Today our electricity supply is still based on the system that Ferranti designed.
Fossil fuels won't go on for ever - oil could run out in 30 years.
The first turbine engines were designed by Charles Parson (1854-1931). Today turbine engines used to generate electricity are still based on his designs.
Michael Faraday (1791-1867) was the first person to create a way of generating a constant current of electricity. His invention led to the power stations we know today.
Save energy - Use energy efficient light bulbs and, when you are leaving a room empty, remember to turn the lights off.
What is a watt? Why is it called a watt? It's a unit measuring electric power, named after James Watt (1736-1819).
In 15 minutes, the sun radiates as much energy onto Earth as all the people on the planet during an entire year. Just imagine if we could channel the sun's energy effectively!
Fossil fuels won't go on for ever - gas could run out in 40 years.
Thomas Alva Edison 1847-1931 is one of the most successful inventors ever, applying for over 1,300 patents by 1910, mainly to do with electrical or mechanical development.
Michael Faraday (1791-1867) is one of the most famous people involved in the discovery and harnessing of electromagnetic force.
All electrical appliances are rated in watts (W) or kilowatts (kW) ( One kilowatt is the same as 1,000 watts). You can use the ratings to compare how much electricity they use.
High voltage electricity is carried across the country by pylons and 'stepped down' for domestic use at substations. The National Grid supplies electricity all over the country.
Fossil fuels won't go on for ever - coal could run out in 250 years.
Save energy - Make sure the dishwasher and washing machine are full before you turn them on and use the lower temperature settings.
Electric shock victims often can't let go of the thing that is passing the electric current into their body. That's because the electricity makes their muscles contract.
Save energy - Don't forget to switch your TV and computer off when you have finished using them.
In the 1780s, Alessandro Volta invented the first battery - all because of Luigi Galvani's experiments with dead frogs.
What is a volt? And why is it called a volt? The volt measures electromotive force. It was named after the Italian inventor Alessandro Volta (1745-1827)
Save energy - Finished playing on your games console or other equipment? Remember to switch off!

Electricity substations

Large substations

Small substations

Pole mounted transformers

Danger

Did you know?