Boiling kettle vs running hot tap

Raxiel

falcieri wrote: »

My shower is electric and I have one of those 4 minute timers from United Utilities to time me. Needs must. The water in the shower runs through hot pretty fast so I don't worry about that. As for the tap, I do feel that the kettle is still the best option (at least after Economy Energy have put my prices up next month).

That is one of the advantages of an electric shower, the water is heated at the point of use. So with electric heaters being 100% efficient there's no wastage (not counting producing and transmitting the power of course). But that 3x unit price premium blows it all away.

Cardew

I have lost count of the number of times this subject has been raised and, as the stated in the points above, the conclusion is that it depends on the configuration of your heating system; thus there isn't a 'one size fits all' answer!

silverwhistle

ajbell wrote: »

Personally I wait for my pv output to reach 2.5kw and flick the switch on my kettle but this does mean I can only have a cup of tea on a sunny day.

AJBell is teasing folks, what PVer would have a 2.5kw kettle when 1.8kws are available?


But it does illustrate that different circumstances give different answers. I've got a hot water tank which is normally heated by spare solar PV and I use virtually no gas for 6/7 months of the year (1 unit/10kwh each for the two summer bills).



Upstairs there's a short pipe run and it comes through very quickly, downstairs I have to run the tap a bit, but during the summer months do that into a small bucket for watering the garden. I could go upstairs I suppose to fill the bowl... Even with water metering I don't notice the cost.

[Deleted User]

Chris, i've just read that article, and to be honest, it dosen't make sense.

They say a dishwasher uses between 0.87 and 1.59kwh of energy per cycle. And 18 litres of water.

My sink takes 0.6kwh to fill with gas powered heating, (which is 5 times cheaper than the electricty it would cost ME to use a dishwasher), and 7 litres of water.

So, even on their most 'efficient' 'Energy Star rated' cycle of 0.87kwh.
0.87x 15p = 13p
0.6x2.8p = 1.68p

Plus the more than double amount of water used in the dishwasher obviously.

How they draw their conclusion is anyones guess!

chrisw99

I think they are going off the assumption that it's a full load of very soiled dishes, which would probably require several sinkfuls of hand washing and lots of rinsing. And probably lots of rinsing first to get the major soiling off.

Dishwashing is one of those areas where I'd gladly pay the 13p to give me an easy life, than 2p and waste half an hour of precious time.

[Deleted User]

Lol Chris, as i said in other thread, cost v convenience.


Major soiling? What on earth are you eating!


Scrape plates into bin, don marigolds, straight into bowl of hot soapy water, quick scrub with sponge, 6-10 seconds, bish bash bosh - job done. Next!

RedbullRJ

As others have said, electric is approx. 3 times the price of gas. However, with either a combi or convetional boiler, you will be leaving hot water in the pipe work between the tap and source.

If combi is in the kitchen this, is likely a small run of 15mm pipe, if conventional, then a longer run of possibly 22mm pipe to the airing cupboard. With the combi though, it will have to heat up the boiler's primary and secondary heat exchangers as well and so these may cancel each other out depending on your varibles. In the winter though this waste heat goes to heating your home up and the boiler is likely already warm from heating the rads.

Therefore very rough guide: Summer when heating off kettle likely cheaper, winter when heating on hot tap likley cheaper.

The differnces will be very small though, so also need to consider time wasted waiting for the kettle, wear and tear on boiler v kettle and replacement costs of each and the safety of each, i.e. more likley to scald yourself with boiling water from a kettle.

S0litaire

surprised no one has mentioned those "Instant Hot Water taps" you can get now...

https://www.amazon.co.uk/s/ref=nb_sb_noss?url=search-alias%3Ddiy&field-keywords=instant+heater+tap&rh=n%3A79903031%2Ck%3Ainstant+heater+tap

Mains voltage into a water pipe... what could possibly go wrong. lol

Raxiel

S0litaire wrote: »

surprised no one has mentioned those "Instant Hot Water taps" you can get now...

https://www.amazon.co.uk/s/ref=nb_sb_noss?url=search-alias%3Ddiy&field-keywords=instant+heater+tap&rh=n%3A79903031%2Ck%3Ainstant+heater+tap

Mains voltage into a water pipe... what could possibly go wrong. lol

You mean, like an electric shower?

S0litaire

Raxiel wrote: »

You mean, like an electric shower?

Yeh....
but an Electric shower over the sink would just look silly...