How much electricity are you using?
Monday 18th February 2013
If you want to save electricity (and why wouldn’t you?) it helps to focus on the things that use most, and so cost you the most money. In other words: 'what uses watt'?
Some electrical items use a lot of electricity. Others don’t. As a rule, those with moving parts or which produce heat use much more than those producing light or sound.
So if you want to save electricity and money, there’s no point worrying about a digital clock or an electric razor since these use so little power you would hardly notice the difference. The big savings lie elsewhere.
Every electrical appliance has a power rating which tells you how much electricity it needs to work. This is usually given in watts (W) or kilowatts (kW). Of course, the amount of electricity it uses depends on how long it’s on for, and this is measured in kilowatt-hours (kWh).
Most of a household’s electricity bill goes on appliances like dishwashers
An item like a fridge has a low wattage, but because it’s on all the time it’ll use a lot of electricity. And although an iron is only used now and again, it uses a lot of electricty so the quicker you do your ironing the better.
The table below lists common appliances and an average power rating (the actual power rating can vary a lot depending on size and model)
| Appliance | Rating | Appliance | Rating | |
| Electric Shower | 4000W | Electric Mower | 1200W | |
| Immersion Heater | 3000W | Electric Drill | 800W | |
| Dishwasher | 3000W | Microwave | 750W | |
| Washing machine | 2500W | Vaccum Cleaner | 750W | |
| Tumble Dryer | 2500W | Hairdryer | 500W | |
| Kettle | 2000W | Plasma TV | 400W | |
| Electric fire | 2000W | Fridge-Freezer | 300W | |
| Deep fryer | 2000W | Freezer | 300W | |
| Toaster | 1400W | Heating Blanket | 200W | |
| Oil -Filed radiator | 1400W | Fridge | 100W | |
| Iron | 1200W | Video/DVD or CD | 100W | |
| Oven | 1200W | PC/Laptop | 100W | |
| Grill/Hob | 1200W | LCD TV | 100W |
Electricity is sold by the kilowatt-hour (kWh) – usually referred to as ‘units’ on your electricity bill. If you’re feeling mathmatical you can work out how much a particular appliance costs to run by multiplying its wattage by the amount of time it’s on and then by the cost of electricity per kWh.
For example, let’s say you have a 1200 W oven (i.e. 1.2 kW) and you use this to cook a roast dinner in three hours. The electricity used is 1.2 (kW) x 3 (hours) = 3.6 kWh. If your electricity costs 14p per kWh (and of course it can vary enormously) then this will cost you 3.6 x 14 = 50.4p. This shows you why energy-efficient goods – those rated ‘A’ on energy labels – save you money.
Source: Centre for Sustainable Energy
