dpb

Microwaved coffee and put the rest toward your inheritence

ricardo

From ScoTTyB's tests I'd say the efficiency difference between electric kettle and gas hob is much larger than the 0.9 and 0.7 used by warrenm2.

If the kettle used 220 kJ and the gas hob used 720 then the gas hob is about 3.3 times worse, so if the kettle stays at a nominal 0.9 the gas hob ends up at 0.27.

Then warrenm2's total for gas is 526kJ instead of 203kJ.

Therefore price to boil a cuppa on

gas = 526*453/3600 = 0·66p
leccy =158.12*66/3600 = 0·555p

In other words, we can't tell without an exact measurement of the amount of gas and elactricity used

warrenm2

mmm I'd be REALLY surprised at that transfer efficiency! Infact looking around the web I found eBay.co.uk Guides - Buying a Hob Electric or Gas which gives a restated efficiency of gas hob as 0.55, giving an energy requirement of 258.5kJ and making my revised gas cost at 0.248p

(my B.Eng coming in useful at last! )

warrenm2

And to all the other people commenting on different ways of making/heating the cuppa, you are forgetting your GCSE physics. Sure there are some differences in the efficiencies of these devices but the fact remains, that the amount of energy required to heat a set amount of water, a set amount of temperature always requires the same amount of energy. The differences in efficiency are small compared to the cost differential between electricity and gas

speedking

Don't forget this is a Subaru site.

Drive home at 100mph. Spray water onto front discs and exhaust. Catch hot water as it drips off. Virtually free hot water, (although the flavour is an acquired taste )

AndyC_772

iTrader: (2)

Whether or not that's true is exactly what all the above calculations are trying to determine!

You're right that the same amount of energy has to be transferred into the water in each case, but the amount of energy that doesn't end up in the water is considerable. If you don't believe me, make yourself a nice cup of tea, then before it's had chance to cool down, firmly grasp the kettle element or gas ring. Report back when the smell of frying bacon has subsided

warrenm2

Andy,

Check the link that I posted, it gives the efficiencies. the difference between 0.55 and 0.9 is a factor of 1.6. The difference between gas and leccy prices are 3.453 to 12.66, a factor of 3.7, hence the price is the largest factor - easily outweighing the efficiency issues

Boost II

iTrader: (1)

The calculations are too simple. You gotta first establish the boiling point of the water which will vary with altitude and the weather. Also you have to allow for energy which escapes as water vapour and steam before your kettle gets up to the boiling point. I suspect the boiling point of the water is going to vary depending on the dissolved mineral content too. I expect there is a whole load of other real world stuff to consider in addition.

sarasquares

iTrader: (1)

has anyone mentioned a tea pot yet?

Steve Whitehorn

iTrader: (13)

What have I started LOL

ronjeramy

iTrader: (1)

Tea pot

Leslie

But it is so interesting!

Les

J4CKO

iTrader: (1)

Anyone just considered drinking tap water instead ?

I am getting tight now things are getting more expensive, like using the showers at work after cycling in, its great, save the petrol, the water and the electricity !

I am so hoping that the British public embrace the energy saving and thrift mentality in conjunction with companies providing more efficient appliances, vehicles and renewable energy, then at some point in the future we are less reliant on Fossil fuels, to the point where the price plummets and they cant give it away, might take a long time but you never know.

dunx

iTrader: (3)

Speedking, you need BTC spec water cooled calipers, once flushed thro' will make a fine cup of coffee !

LOL

DunxC

P.S. Energy efficient my RS, my new washer has a cold feed only....

jonc

Yeah but which method creates more CO2, (since that is a hot topic these days!)

Shark Man

Tricky that, I'm going for eleccy being the more polluting (excluding nuke and renewable/green sources):

Fuel source-->process fuel--tranport fuel-->Burn fuel-->boil water-->create steam-->drive turbines->step up tranformer-->national grid-->step down transformers-->home-->kettle-->water.

Its just one huge circle: Boiling water to boil water somewhere else!

Gas reserve-->Process-->pressurise-->network-->storage-->network-->house-->hob-->kettle-->water

At least that is a little more direct.

Steve Whitehorn

iTrader: (13)

Well here I am sippingmy cup of tea....and after all that....

Sod it....

...I will just stick with Gas


(Interesting points about the CO2 thing Shark Man)

dunx

iTrader: (3)

Back to chop down a tree and boil pan over fire = CO2....

LOL

DunxC

P.S. I'm drinking cider from now on !

Gav

You all need to but one of THESE. They cost about Ł800 to buy but you soon make back the costs on the energy you save. Instant boiling water and you only use what you need i.e you want a cup of tea, you just fill your cup directly from the tap!

Plus we sell them so if anyone wants one, come to me

warrenm2

LOL - That would absolutely never pay for itself unless you brim your kettle every time you want a cuppa!

Gav

The fact that people often boil more water than they use and has been said on this thread boil it twice due to forgetting, they significantly save energy. Why waste the energy on boiling a litre of water to fill one cup of tea? The fact is they are proven to save energy and money

warrenm2

Proven is not a word I would use - try doing the sums for yourself!

AndyC_772

iTrader: (2)

When I worked it out a while ago, boiling exactly enough water for a cuppa cost about 1p in electricity. Assuming the actual cost were 2p - hopelessly wasteful, really - your Ł800 gadget would have to make 80,000 cups to pay for itself. At 3 cups a day that's payback in a mere 73 years

Might make more sense on a building site!

[edit]: just checked the site, apparently it uses a continuous 10W, or 3p a day, whether it's used or not - so in fact at 3 cups a day it'll pay for itself... never!

WRX_Dazza

isnt' electricity cheaper at night on some tarrifs??

make all you tea between 11pm and 4am. sorted !!!



some great calculations on here btw. !!

powerwrx

iTrader: (11)

get up, fill the kettle (electric or gas) and boil.... take a thermos flask,and fill with your favourite tea or coffee...and there you have it, one flask full of your favourite to last throughout the day and your only using the kettle once ooooohh the money ull save

Shark Man

I do that when out camping: thermos of boiling water. And reheat it on the stove when I want a proper hot brew.

Couple times I've had a few peeps who hadn't gone with me before admiring my stove at how quick it boiled water (they didn't see me fill the kettle from teh thermos).

Coffin Dodger

Why hide this URL in the post

Worst spammer ever

StickyMicky

On another note, look at the posts from GAV


he hit 5000 posts and then stopped posting last year?

how random

StickyMicky

he has just logged in, i have awoken him

ALi-B

iTrader: (1)

Allow me to do the honours