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# How Is Electricity Measured in the UK?

Understanding your electricity bill will ensure you can check the charges – and be confident that they’re correct and you’re not overpaying. Comparing the bill with your meter readings will confirm this.

This information will prove extremely useful if you want to switch suppliers, or simply monitor your electricity use. How is electricity measured in UK? Read on…

Electricity Facts

## What is electricity?

In simple terms, electricity is the flow of electric charge – and is a form of energy used to power electrical devices and machines. The most common way of transferring this energy is with the flow of electrons through conductors like copper wires. When electricity flows it’s called electric current.

## What is a watt?

A watt is a measurement of power – the rate at which electricity is being used at a specific moment. And is named after James Watt who invented the steam engine. A watt is equal to one ampere under the pressure of one volt.

One watt is a small amount of power – devices need either a few watts to operate, or much larger amounts when the watt becomes a kilowatt. Electricity generation capacity is measured in multiples of kilowatts.

Watt hours describe the total amount of electricity used over a period of time – a combination of the speed of the electricity and the length of time used.

## What is a kilowatt hour?

A kilowatt hour is a measure of how much energy is being used and doesn’t relate directly to how many kilowatts you’re using each hour. The unit of measurement equals the amount of energy you would use if you kept a 1000-watt appliance running for an hour.

Depending on the size of your home and the number of people in your family you may use approximately between 3,200 and 4,900 kWh of electricity each year.

## What is a megawatt hour?

Megawatts are a measuring tool for the output of a power plant – or the amount of electricity used by an entire city. Mathematically speaking one megawatt = 1,000 kilowatts = 1,000,000 watts.

## What is a gigawatt?

Gigawatts measure the capacity of huge power plants – or several plants. One gigawatt = I,000 megawatts = one billion watts.

## What is a unit of electricity?

A unit of electricity is used to measure the amount of energy expended at a property. Your electricity company will charge you an amount in pence for each unit of electricity used.

The amount consumed by an electrical item or appliance depends on the wattage – and this is displayed on all electrical appliances. The numbers displayed on your electricity meter are in kilowatt hours (kWh).

Electricity meters fall into four basic categories – digital, electronic, dial, and smart meters – where you don’t need to do anything as they automatically send your reading to your supplier.

How to read an electricity meter is quite simple if you follow these guidelines:

Digital meter – read the black numbers from left to right – ignoring the numbers in red or surrounded in red. If there’s more than one row of figures this is your lower priced off-peak electricity reading. Record them exactly as above.

Electronic meter – you may need to press the cycle display button to take the reading – others automatically scroll through the displays. Write down all the numbers from left to right in every display – again ignoring any numbers in red or surrounded in red.

Dial meter – each dial on every meter starts at 0 and goes through to 9 before beginning the cycle again. Read the dials from left to right – if the pointer is between two numbers record the lower one. If the pointer falls between 9 and 0, record 9 and lower the reading on the dial to the left by one. Ignore the last dial on the right