To work out how much electricity costs you must first understand how companies charge you for it. Most UK public utility companies charge per kilowatt-hour (kWH). This measurement is almost an industry standard and effectively refers to 1000 watts for 1 hour. So if you have an electrical appliance which has a consumption of 1000 watts and you leave it on for 1 hours thats a kilowatt hour! Simple hey?
To get kilowatt-hours, take the wattage of the device, multiply by the number of hours you use it, and divide by 1000. (Dividing by 1000 changes it from watt-hours to kilowatt-hours.)
The table below shows some common electrical appliances and how much wattage they consume, i’ll also show you how much they’ll cost. Let’s assume you have an energy rate agreed with your energy company of £0.139p.
|light bulb||100 watts||730 hours
(i.e., all month)
(73 x 0.139p = 10.147 rounded(10.15)
|Mid Range Kettle||2000 watts||5 hours
(i.e., 2 boils p/d at 5 mins per boil)
(10 x 0.139p = 1.39
|Sony 52″ LED Flatscreen TV||122.55 watts||166 hours p/m
(39 hours per week + 2 days at 5 hours)
(20 x 0.139p = 2.82(rounded))
|GHD Hair Straighteners||35 watts||7 hours p/m
(20mins per straighten x 5 p/w)
(20 x 0.139p = 2.82(rounded))
So if your anything like me your thinking hey thats not all that bad, unfortunately as with most houses in the UK now a days we don’t just have the one tv, or the one set of hair straighteners or indeed the one light bulb. On top of which you’ll also be paying oil or gas rates for the heating of your house which will add to the cost.
But this simple formula will help you work out the potential cost of running any electrical appliance.
Also bare in mind that you can’t always be sure that the listed wattage on the box is always true. Some appliances don’t always use the full wattage all of the time.
Many appliances may also list power in amps and not watts, however don’t worry a simple calculation will convert that to watts.
Many people seem to get confused between watts and watt hours, they are very different things this should help:
The difference is:
We use watts to see how hungry a device is for power. (e.g., 125-watt TV is twice as hungry as a 62.5-watt disco ball.)
We use watt-hours to see how much electricity we actually used over a period of time.
So how much does electricity cost?
The cost of your electricity will depend on a number of different things such as where you live, how much you use and more recently possibly the times of day that you use it.
The electric company measures how much electricity you use in kilowatt-hours, abbreviated kWh. Your bill might have multiple charges per kWh and you have to add them all up to get the total cost per kWh.
Electricity rates vary widely. The only way to know what you’re actually paying is to check your bill carefully. You can’t find out your own kWh rate by reading this web page, or any other.
Can I switch to provider lower my bills?
Until recently, no one had a choice about where they got their electricity from. In the UK there is a few big name players such as British Gas, Npower, Southern-Electric and Eon. The list goes on, but one thing is for sure there is now choice for the consumer in the UK and you can shop around, websites such as moneysupermarket will help you find bargains. But beware, websites like this do not act as the middle man without taking a cut, sometimes you might be better off directly approaching the energy company.