Not sure if this is funny or not but it is daft. I noticed one of my wife’s young employees (in her shop) refills the kettle completely to the top once he had taken enough from the kettle for a coffee. Why are you doing that I asked. “So that it is full for the next person”. But why if they are only making 1 cup tea, why boil 2 litres of water? I asked, it is a waste of money and energy .....
His reply was “ that is what we always do in our house, it is bad manners not to”. I stood aghast thinking about the uphill struggle that is needed to educate people in saving energy and not to pollute when a household culture ingrains the opposite in their children.
If we assume that the household in question does this three times a day, they boil 2 litres and then perhaps use enough for 2/3 cups of coffee, then they are boiling at least one litre unnecessarily each time. Boiling a 2 litre kettle uses about 0.2 kWh of energy, 3 times a day and this is 0.6 kWh. So half of this could have been avoided, if the kettle had been half filled, so they could save 0.3 kWh. For a whole year that is 0.3 x 365 = 109.5 kWh that equates to £16.863 (40.2kg) . The number in brackets is the amount of CO2 emitted because of this behavior.
Well its not an enormous amount but it is significant.