Efficient way to boil water

RumRat

welshbookworm wrote: »

An acquaintance of mine boils a full kettle, makes a tea and then puts the rest in a flask to make tea throughout the day
Says that's the cheapest way.

How sad....:sad:

neilmcl

Naf wrote: »

Depends if you're talking about energy efficiency or cost efficiency. Since there is a large disparity between the cost of electricity and gas it is quite possible for the less energy efficient gas hob to be more cost efficient than the electric kettle.

The cost saving of the cheaper gas is outweighed by the lack of energy efficiency. Taking everything into account it's still cheaper to use a modern energy efficient kettle than a gas hob.

Raxiel

neilmcl wrote: »

Fair enough, I slightly misread the post. The element itself will be pretty much 100% efficient at converting energy to heat but that's the same with pretty much all kettles. Heat dissipation and transfer to the kettle body itself will reduce the overall energy efficiency down to around 80-90%.

Yes, that's kind of what I was getting at. Electrical resistive heating elements are all pretty much the same in terms of generating heat, but the kettle in the link traps a lot more of it.
It's not perfect, the ring of black plastic at the base gets warm to the touch after boiling (though not so hot you can't leave your hand on it) while the rest of the steel skin remains at (or close to) ambient. The lid is cool at first but eventually the heat soaks through it, and it's by that route I suspect the kettle eventually looses most of it's heat over the course of several hours.

I couldn't say how much electricity (and therefore money) it's saved since we got it, we've implemented a whole raft of energy efficiency savings over the last couple of years, but I don't regret paying the £25-30 premium over a 'normal' stainless steel kettle.

forgotmyname

Slight flaw with that kettle and its energy saving idea.

It keeps water hot for upto 4 hours? But that means you boiled more water than you needed which would take longer and use more energy in the first place.

So will it actually save any power??

With ours 2 mugs worth is above the minimum and barely leaves anything behind to keep warm.

Is that more efficient?

NaughtiusMaximus

welshbookworm wrote: »

An acquaintance of mine boils a full kettle, makes a tea and then puts the rest in a flask to make tea throughout the day
Says that's the cheapest way.

That's a recipe for a crap cup of tea, the water in the flask will remain hot but not boiling which is what you need for a decent brew. Most Americans have yet to figure this out which is the reason a cup of tea in the states is generally awful.

Naf

neilmcl wrote: »

The cost saving of the cheaper gas is outweighed by the lack of energy efficiency. Taking everything into account it's still cheaper to use a modern energy efficient kettle than a gas hob.

Sure. That's why I said "quite possible", not that I did the maths haha. You could be on a good gas tariff and poor electricity one for example.

Raxiel

forgotmyname wrote: »

Slight flaw with that kettle and its energy saving idea.

It keeps water hot for upto 4 hours? But that means you boiled more water than you needed which would take longer and use more energy in the first place.

So will it actually save any power??

With ours 2 mugs worth is above the minimum and barely leaves anything behind to keep warm.

Is that more efficient?

Well, you don't have to brim it every time. We generally half fill it. If it's more than you need, then yes, you've used more energy than you need now, but if I come back to it an hour later to make a coffee (which I don't want scalding hot anyway) it's free. SWIMBO on the other hand can bring it back to boiling for her tea for a fraction of the energy she'd need for a fresh cup.

It depends how organised you are, predicting how much you need and when. We used to be pretty bad at heating the water, getting distracted with something then having to re-boil - we still are, but now it's not as wasteful :rotfl:

Gloomendoom

Raxiel wrote: »

Well, you don't have to brim it every time. We generally half fill it. If it's more than you need, then yes, you've used more energy than you need now, but if I come back to it an hour later to make a coffee (which I don't want scalding hot anyway) it's free.

It's not free, it's cost you money. You just haven't wasted it.

that

Raxiel wrote: »

We bought one of these http://amzn.eu/aPI40b0

At close to £70, that is a fair amount of electricity you have to recoup. Perhaps not financially efficient? My kettle is a genuine plastic one that I got free from Esso tokens some 25+ years ago

Raxiel

Gloomendoom wrote: »

It's not free, it's cost you money. You just haven't wasted it.

Thanks captain obvious. Effectively free, compared to boiling it, letting it cool, and boiling it again.

that wrote: »

At close to £70, that is a fair amount of electricity you have to recoupe.

I did infer in my first post that it's not necessarily cost efficient. Just Energy efficient.
It depends on your goal. As has been discussed, OP didn't make it clear what kind of efficiency they were talking about so both have been discussed.

That said, the model we got was the £55 model. I won't buy S**ty cheap plastic kettles any more because I only want to taste my beverage, not the water it's made with so that rules out the £5 specials.

A quick browse of well made steel kettles on Amazon puts the price around £26 which narrows the premium. Will it pay for itself fully in terms of kWh saved? Probably not. Do I care? No.

I'm not telling anyone to rush out and buy one, just saying it exists and folk can make their own decision.