Re: Bad tests and worse marketing
Physics aside for a moment... I can see a real world scenario side to this and have experienced it a lot... and found the solution.
Problem - Boiling a kettle with more water in it than you need is a waste of energy - Now you might think 'just put less in it then' but it's not always that easy. If you just want a single cup of water, which is approx 275-300ml for the average cup of tea. Kettles tend not to work with such small amounts in them (they should have protection for low levels to prevent explosions... as my sister once found out by turning on an empty kettle many, many years ago).
The low level indicator on nearly all of my old kettles required at least 600-900ml before it was at the minimum mark. So for a single cup, you are using 3x the amount of energy required.
The other downside to boiling more water than you need... is reboiling the same water for the next cup and the one after that and so forth... ruins the taste of your tea.
The other problem is one I was always doing... put the kettle on, walk off to do something else (chat with a visitor for example) and forget about it... Have to boil the kettle again... either reboiling water or using fresh... both of which are a waste of energy and resources.
The solution has been very simple... I switched to a one cup kettle. Fill it up, it boils 280-300ml of water and fills a single cup. It's perfect, consumes less energy and doesn't waste water or cause reboiling.
Is it a perfect solution... No, the design of the one cup kettles are not perfect. But since I got one, I've never wasted any water or electricity on cups of tea since. In fact my folks have converted to one too. Not only is it easy to use for my disabled dad (who could no longer lift/fill a kettle), but they got the top of the range one with adjustable cup sizes... small for my dad, medium for my mum and because I like the large mug... Guess which setting I choose.
It's not without it's downside... making multiple cups of tea or a pot is kind of a no go now. But it takes 24 seconds from hitting the button to having a mug of hot drink... compared to 2-3 mins to boil my old kettle.
The coffee machines also work in a similar way, such as the tassimo and only boil enough water to fill a cup... Although I do believe some of the older models used to preheat the water to reduce prep times. So if the newer ones don't do that... saves energy.
So I can fully understand if they wanted to regulate kettles in a similar fashion... but if they seriously think they can reduce the power of kettles and outlaw >2kw ones in favour of <1kw ones... they're bonkers.