What does it cost to run appliances ? Will I really save money by fitting LED lights ?
OK Here is the simple explanation of what electricity really costs:
(Here comes the Science Part)
TIP: if you don’t want the Science bit – skip to the paragraph beginning with the word “NOW”
Electricity is charged in “Units” – Typical cost per unit is around £0.16p per unit (varies depending on what deal you are on check your bill to find out )
1 “Unit” = 1 Kilo-Watt-Hour (KW/hr) = 1000 Watts for 1 hour, 100 Watts for 10 hours 10 Watts for 100 hours.
So to work out the cost of running an appliance – examine it – somewhere you will find a label telling your how many Watts (or KW) it uses… then work out over time…
So a 2KW toaster will cost £0.32 per hour (2 * £0.16) (of course the toast will be well burnt after one hour!)
A 100W light will cost £0.016 (1.6p) per hour…. (£0.16 * 0.1KW)
A 10W light will cost around £0.0016 per hour (1.6P for 10 hours!)
A 13W LED give roughly the same light as a 100W bulb so:
Assuming your 13W LED bulb costs you around £9.00 (current Wickes price), this will cost:
1000 (1KW) divided by 13 = 77. So this means that it will take 1 KW/hr to run your LED for 77 hours as opposed to 10 hours for your old 100W lightbulb.
This means every 67 hours out of every 77 will be “free” electricity compared with the 100W bulb.
So every 67 hours, you save use 16p by using your 13W LED light.
It cost you 900p to buy the bulb, so you will get your money back after (900p divided by 16p) = 56 times…
Meaning that after 56 * 77 hours = 4312 hours, or 179 days, burning constantly.
NOW after 179 continual days – This bulb has paid for itself. (Whoopee!) Allow for the fact that you really only use the light for about 4 hours a day…. so that’s 179 days x 6 (24 divided by 4 = 6) so you will be saving money after 1074 days – or nearly 3 years to break even!
If you want to know what any appliance costs per hour – just take the Wattage marked on the appliance, divide 1000 by the wattage – and this gives you how many hours you can run the appliance for 1 Unit…
So example: A 50W heated towel rail = 1000 divided by 50 = 20 = It would run for 20 hours for 16p!