I found this on the internet. I don’t know how accurate it is but it seems reasonable and might be of some help. Making some adjustments might make a big difference to our bills. Look at the difference between LED and normal light bulbs?

The amount of energy used is a factor of:

• The rating (watts)
• The price you are charged per unit of energy (your energy tariff)
• How long the appliance is running for?

This means to reduce the cost, use a different appliance or how long they are run. I hope this helps.