I just read on the BBC website that high-powered hair dryers, kettles and toasters are next in line to be banned. Surely physics dictates the amount of power to boil a kettle of water, a low-powered kettle would be working longer to do its job? And wouldn't a low-powered hair dryer or toaster simply be used for longer to do their jobs?
Does anyone have a logical explanation?
If you can make something more efficient then you can do the same job with less power. A fairly sensible argument and probably going against the trend of bigger numbers is better.
Lower powered toasters may lead to less burnt toast - a double whammy saving on carbon emissions!!
If you can make something more efficient then you can do the same job with less power.
Making a kettle more efficient is certainly an interesting concept. Where is the waste energy going - heat?
Crucially, you're not going to inconvenience anyone enormously so it's easy legislation to pass. Limit air travel, huge tellies and ban cars emitting more than x co2 and you'd suddenly have a fight on your hands.
Has Kelvin MacKenzie taken over the BBC?
Does anyone have a logical explanation?
It saves energy.
HTH
Stockpile your high-powered kettles now.
I don't understand the fuss over the recent vacuumcleaner power reduction thing. Our Henry is 1200w max,yet much more efficient thant the 1600w Black and Decker crap it replaced.
My dad used to do the calculations as part of teaching - kettles are about 98% efficient.
I suspect that hairdryers are toasters aren't that efficient though so with some design work they could be improved. Don't know for sure though.
Where is the waste energy going - heat?
Heat that isn't directed towards the water?
So you can voluntarily choose a Henry in preference rather than having the decision dictated to you.
ever tried getting a decent cuppa from a 2000w kettle ....
Making a kettle more efficient is certainly an interesting concept. Where is the waste energy going - heat?
Through the sides, using more energy that is required to heat the water - think about it can you touch the side of the kettle as it boils? If you can it's probably heating the water very efficently. The tap boilers and small volume kettles are the real solution there as most people boil 4x as much water as they need and then most kettles probably get boiled 2 or 3 times before every use.
Please let them go after irons. A more frivolous waste of energy you couldn't make up. "These clothes are not quite flat so, for pure vanity's sake, we'll continually heat some steel with a 2kw element and make them flat."
I already use low-energy tea bags, so it's not a big deal for me.
Making a kettle more efficient is certainly an interesting concept. Where is the waste energy going - heat?
Limiting the power of your kettle encourages you to only put in as much water as you actually need, rather than (as my wife does) putting in a litre or so of water, boiling that, and then letting 3/4 of it cool back down to room temperature.
About the only thing you could do to a kettle is make it switch off 1 deg cooler or something.
Toasters, well there's a big gaping hole at the top. Capture that heat to use for something else, or use some kind of laser device than can spot cook the surface of you toast?
Hair dryer, just turn down the heat a little bit, and have a more efficient blowy motor.
Sounds nearly as silly as the day that UK "changed" to 230V AC +/- however many percent, instead of 240V. Remember the papers and BBC news saying how long extra it would take for kettle to boil. the voltage didn't actually change. As we proved a long time after by sticking a multimeter in the mains socket.
Please let them go after irons. A more frivolous waste of energy you couldn't make up.
Exhibit A m'lud
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I give you the low energy version
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As ever, the headlines are mainly bollocks.
Its a study, not even an imminent or even proposed ban.
Here is the linked report if you can be bothered to read it.
Kettles start at page 55. I've only skimmed it, but they seemed to be more concerned with making them more durable, so saving raw materials and energy in construction.
The biggest saving with kettles would be boiling only the water required. I remember seeing a kettle (?) that did this, heated the water as it was being drawn from the its reservoir.
edit - as mikewsmith said...
Kettles with insulation seems a good idea; my wife fills up the kettle before making even one drink as saves her walking over to the sink so often.... It does seem to me that the one who isn't earning the money is less concerned about efficiency than the one who is - or is it just often a woman thing to leave things on when not needed? This is just going on what my mates moan about obviously!
Limiting the power of your kettle encourages you to only put in as much water as you actually need, rather than (as my wife does) putting in a litre or so of water, boiling that, and then letting 3/4 of it cool back down to room temperature.
In Winter, that's fine as it just acts as a radiator. In Summer it's a bit wasteful.
also for those miserable gits who want their 6l V8 Kettles because they sound better and the tea tastes much better from a proper kettle/iron/toaster/hair dryer when you come to buy a new one you will just get a new one that does the same job just as well but costs you less money.
Surely the handmade, artisan, 853, slack handled kettle can be boiled atop the woodburner?
And they're bringing a new sized toaster out next year anyway.
It's inspirational, aspirational and makes your muffins come alive
What olddog says.
In fact putting a power limit on a kettle could be counter-productive to saving energy.
Let's say a kettle's power is limited to 1KW, if I want it to heat as quickly as a 3kW one I could do this by designing the kettle to have a reservoir of water that is pre-heated at 60C, so that the 1KW of power could bring it up boiling in the same time as 3KW.
Fantastically wasteful of energy, but uses less power. I can't imagine people would make such a unit, but it highlights the problem of legislating on power rather than energy. I assume that they hope that by reducing power people will put less water in the thing in the first place.
My home is heated from electricity anyway, so at least with a kettle I get a cup of tea and an extra radiator.
We all need to be more efficient in our use of energy really so going after all the power hungry appliances that are more powerful than they need to be to mitigate poor design seems a good place as any to start
High powered kettles mean you can boil a larger amount of water in the same time as a low power kettle boils a small amount. Which probably explains why everyone in my office boils a gallon of water in order to make a cup of tea- if it took 5 minutes to boil, they'd put in less water to get it to boil fater, and use less water and less electricity.
Disposability seems like an issue too though. Are higher powered electrical items likely to have a shorter life? Do they consume more resources to produce?
Sounds nearly as silly as the day that UK "changed" to 230V AC +/- however many percent, instead of 240V. Remember the papers and BBC news saying how long extra it would take for kettle to boil. the voltage didn't actually change. As we proved a long time after by sticking a multimeter in the mains socket.
It did, but the variation in mains voltage is quite high anyway afaik.
I don't use a hair dryer and only one room in our house is carpeted anyway, so they can do what they like with appliances 😛
Isn't this all a drop in the ocean compared with air travel and people using great gas-guzzling monster trucks to go to sainsburys or to transpet a tiny child to nursery?
We all need to be more efficient in our use of energy really so going after all the power hungry appliances that are more powerful than they need to be to mitigate poor design seems a good place as any to start
I think a kettle or toaster's duty cycle is so low that it would make chuff all difference.
Now I've thought about it a bit more, it may well be more about reducing peak power usage than energy.
2 million 1KW kettles going on after Coronation street may mean you can use a different energy supply structure compared to 2 million 3KW kettles being switched on.
Isn't this all a drop in the ocean compared with air travel and people using great gas-guzzling monster trucks to go to sainsburys or to transpet a tiny child to nursery?
Is it? Why don't you do some calculations?
Most people boil kettles 2, 3 or 4x a day, but not everyone flies, and most of those will only go once a year...
Does anyone have a logical explanation?
Yes. Some people (including policy makers) don't understand the difference/relationship between power and energy. And you can enact virtually any legislation that makes things slightly worse if you remember to use the word "sustainable".
Even if we all didn't use anything during the day, we'd only reduce consumption by roughly a third:
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Diurnal variation is quite small, we use 20+ GWatts round the clock (I assume Industrial stuff).
It did, but the variation in mains voltage is quite high anyway afaik.
nothing changed to the actual supply. there is no big knob to turn, merely thousands/millions of substations to replace at midnight on harmonisation night. the variation was chosen to so that all EU existing supplies fall within the harmonised range.
Other considerations aside, a lower power kettle will actually be less efficient than a higher powered one. It'll take longer to boil the same amount of water, so more energy will be lost to the environment whilst it's heating the water, and more energy will be consumed overall bringing it to the boil.
It may discourage people from boiling more water than they need, but we've already got decent incentives for people to not do that.
Molgrips - My maths isn't up to calculations but lots of people drive huge cars short distances every day without thinking that they could walk that mile to the shops or take their child to nursery on the back of a bike.
And I think you're underestimating air travel. I travel abroad maybe 3 times a year for work and that's pretty infrequently compared with a lot of friends or people I work with.
I'd aim at things like aircon. By definition inefficient. On for extended durations, and a net heat generator whose job is to make cold.
edit: or at least rule that they must be solar powered or something
2 million 1KW kettles going on after Coronation street may mean you can use a different energy supply structure compared to 2 million 3KW kettles being switched on.
How about banning the likes of Coronation Street/Eastenders? - in a single stroke it would reduce the amount of kettles being boiled and crap TV.
lots of people drive huge cars short distances every day without thinking that they could walk that mile to the shops or take their child to nursery on the back of a bike.
Yes, I know, but you'd be surprised at how much other things add up. Look at the whole picture, don't just focus on the headline stuff.
Incidentally most people I know don't fly anywhere.
pdw - Member
Other considerations aside, a lower power kettle will actually be less efficient than a higher powered one. It'll take longer to boil the same amount of water, so more energy will be lost to the environment whilst it's heating the water, and more energy will be consumed overall bringing it to the boil.
as pointed out earlier it's a study not a law which means it's options being looked at. Perhaps banning kettles completely would be better. It also gives people the opportunity to look at designs.
The amount of water in the kettle is the important factor.
The amount of energy required to heat water of a certain volume is the same regardless of the the heating element power (energy = power x time).
higher power element = less time. Lower powered element = more time. Specific heat capacity of water = constant.
Pretty brainless policy (suprise surprise).
They'd have been better off making the volumetric capacity of the kettles smaller (say 2 mugs max).
Is it? Why don't you do some calculations?
Because if I did you'd only take issue with them 🙂
If I need to heat up a litre of water it takes a given number of joules -let's say 350Kj - that figure is assuming we've got a perfect insulator - which we haven't. The longer it takes to warm up the water the more energy leaks to the surrounds and the less efficient it becomes. For a given volume of fluid more power is more energy efficient (at the point of heating)
Now you could argue that it would encourage people to use less water, but if you're already a good ecologically minded person you're already using the minimum quantity, only now you have a less energy efficient kettle to do it with.
Making a kettle more efficient is certainly an interesting concept. Where is the waste energy going - heat?
Well I'm no expert (stereotypical STW IT bod) but can come up with a few ideas straight off (I'm sure a few others may have suggested some or all of these, I've not read every post)
-The casing of my kettle gets hot each time it's used, and that heat radiates into the room, that's wasted energy. The water could possibly be insulated somehow maybe, something like a jetboil? maybe
-Kettles are open to atmosphere so heat is wasted their. could that be sealed? Much like a litre of water on the hob boils quicker when it has lid on.
-Far too many people boil way too much water not just what they need (these include my wife despite much nagging, my mum, my grandparents). many people don't think! so need to be lead\pushed! So those boil water tap kettle things seem like a good idea too.
Many manufacturers making money doing what's cheap and easy often need a push to innovate. Some don't, Dyson for example. As I understand it not one of their vacuums use more than 1600w anyway....
Some people need pushing, it's a good thing IMO vacuums, kettles, irons, hair-dryers etc. Yes for most of those the gains might be small but look after the pennies and........
