I've seen a lot of threads on here with people asking about their energy bills.
So a few basics here - and then I am sure people can add their own.
The price cap is an average expectation of what a household will pay. It's based on typical consumption and can vary between areas.
There is a daily standing charge and a cost per kilowatt hour.
There are figures available on typical energy consumption in a house.
According to Ofgem, the average household in the UK has 2.4 people living in it, and uses 2,900 kWh of electricity and 12,000 kWh of gas respectively. This works out as an average of 242 kWh of electricity, and 1,000 kWh of gas, per month
Electric devices have a power rating - in watts.
Devices that need a lot of power have a high power rating.
If you use a 1000 watt device for 1 hour, you have used 1 KWH of power (1000 watt hours)
That's 1 unit - about 28 pence with the new rating.
If you use the same 1000 watt device for 1/2 hour, that's 0.5 KWH - 0.5 units.
So if you use a 100 watt device for 10 hours, that's also 1 KWH (as it's low power but for a longer time)
Heaters are high users as they are on for a long time. As are immersion heaters.
Gas is different - you need to use a formula to change the volume of gas used from cubic metres into kilowatt hours.
A Smart meter will give you an indication of when there is a high energy demand, but don't forget that a low power device on for a long time will end up using a lot of energy.
So it's the kilowatt hours you need to look at whenever you question your bill.