Is one of our boilers more expensive to run than a kettle?
No, in fact it becomes cheaper the more people that use it.
Here’s how we know:
Units of electricity are measured in kilowatt hours (kWh) at current rates, one unit of electricity costs about 12p.
To work out how much an electrical item costs to run, you multiply the items power by the amount of time that it is on.
Power (kW) x time (h) = electric used (kWh)
An average kettle is 3kW and takes 4 minutes (0.07 hours) to boil.
So 3kW x 0.07h = 0.21kWh
0.21 x 12p = 2.5p
So it costs about 2.5p to boil a kettle of water
If all the water in that kettle is used it will produce 5 decent mugs of hot water.
If you have 10 staff that have 4 mugs a day each, that’s 40 mugs so, the kettle will be boiled a minimum of 8 times (probably more as no-one ever empties it entirely!)
So 10 staff, 40 mugs, 8 boils 8 x 2.5p = 20p per day
Or 20 staff, 80 mugs, 16 boils 16 x 2.5p = 40p per day
And so on…….. 30 staff 60p a day, 40 staff 80p per day………
The electrical consumption of the 100C (which also has a 3kW heating element) while on standby is 0.07kWh, which means that it will use one unit of electricity (12p) in 14 hours which is 0.86p per hour, or 20.6p per day.
As the 100C is designed so that it only boils the water that is used each time. It will run for 30 seconds for each mug of water that is taken out… 1 minute for 2 mugs..2 minutes for 4 mugs..
So for 10 staff, 40 mugs it will be on for 20 minutes (0.3 hours) throughout the day
So 3kW x 0.3h = 0.9kWh 0.9 x 12p = 10.8p
Add this to the standby amount of 20.6p per day gives a total of
For 10 staff, 40 mugs 31.4p per day
For 20 staff, 80 mugs 42.2p per day
For 30 staff, 120 mugs 53p per day