If you’ve looked at your energy bill lately, you’ve probably come across the term ‘kilowatt hour’. It’s a confusing piece of jargon that trips may people up. In this article, we’ll explain what a kilowatt hour is and answer some other common questions.
What is a kilowatt hour?
Put very simply, a kilowatt hour (or kWh) is a unit of energy. Much like you pay for petrol by the litre or phone calls by the minute, you pay for gas and electricity by the kilowatt hour.
When you’re shopping around for gas & electricity, suppliers have to quote their prices in pence per kilowatt hour (Ofgem says so). This makes it easier to compare prices and find a good deal.
For those interested in the technical definition, here it is:
For example, a 1 kW heater left running for 1 hour would consume 1 kWh (or 1 unit) of energy.
What is the cost per kilowatt hour?
There isn’t a standard price – it depends on both your energy supplier and the tariff you are currently signed up to.
Unit prices for electricity can range from around 12-18 pence per kWh. Gas is around 3-4 pence per kWh.
Note that you also pay a standing charge with most energy tariffs – you can find more information about standing charges here.
What’s the difference between a kilowatt and a kilowatt hour?
A kilowatt is a unit of power. The kilowatt (kW) rating of an appliance describes how quickly it uses energy.
A kilowatt hour is a unit of energy. It describes an amount of energy consumed.
Put it this way – if kilowatt was like the speed of a car, a kilowatt hour would be how far it has travelled.
How do I find out how many kWh I use?
If you are shopping around for a new energy supplier, it’s useful to know how many kWh your home uses in a month. You can get this information from your current provider – either by looking at a paper bill or by checking your online account.
If you can’t find your exact usage, you can still compare prices using something called Typical Domestic Consumption Values – or TDCVs.
TDCVs are calculated by Ofgem using data from typical households, as shown below:
For example, a small family living in a 3-bedroom house would probably be classed as a ‘medium use’ home. They could expect to use around 12,000 kWh of gas and 3,100 kWh of electricity in a year.
How do I reduce my energy consumption?
Concerned that your kWh use is too high and costing too much? There are two things you can do: