Gas hob vs electric kettle

Krakkkers

Just boiled 400ml on gas hob in saucepan with lid vs 400ml in electric kettle and results are.
Electric kettle 55 seconds and 45wh which is 1.51p
Gas hob 3 minutes and 0.011 units (0.123 kwh) which is 1.26p

ariarnia

closer than i would have thought given the price difference between gas and electric. was there much difference in the amount of water left after boiling for three mins (was a lot boiled away or was it still a full mug full?)

Krakkkers

There was not much evaporation as i used a saucepan with a lid on and turned the gas off the second it started boiling.
Almost 3 times the energy in kws used to heat by gas but slightly cheaper overall, may be a hob kettle would be more efficient than a saucepan and lid but it is what it is.

ariarnia

i don't know about that. it was why i asked. we have a log stove and sometimes i will use a stove top kettle to boil water for hot water bottles or a cup of tea. its free heat. but i also see the steam coming out of the kettle and you are supposed to let it boil so its standing a hand away whistling loud (because you can't see the water to see when its properly boiled) and it always looks like so much more steam than comes from the kettle when its done so i wondered how much water it was putting into the air (we ventilate regularly so i'm not all that worried. just curious). 

thanks for trying it and letting us know. 

mmmmikey

In the interests of science I just tried it too, comparing a 3kW electric jug kettle with a stove top kettle and a butane gas hob. I used 400ml of water for each test. Csts are EPG rates for East Midlands.

My figures are:

Electric kettle: 1 minute 5 sec, 55Wh, at 33.02p/kWh = 1.82p

Gas kettle: 1 minute 35 sec, 82Wh, at 10.237p/kWh = 0.84p

Not the most scientific experiment but I'm in the same ball park as @Krakkkers for the electric kettle but more efficient using the gas kettle.

C_Mababejive

If using the gas hob it seems to me there are far more variables ie the size of burner, how well you keep it turned down so that all the flames impinge on the base of the kettle, the type of kettle or saucepan etc. Also the heat from the flueless hob is discharged into the room to heat the home whereas most of the kettles energy is more directly discharged into the water save for radiant heat from the body of the kettle and any steam that is vented.

Krakkkers

Agreed,  more variables when heating water with gas but it seems to be cheaper overall at least on small quantities like a mug full.

facade

I have a hob kettle. It takes ages to boil compared with the 3kW electric, so I put it on, sit down and forget all about it (literally) until it whistles, whereas the electric boils in around a minute- I flick it off when it sounds boiling (the noise of the collapsing bubbles stops) as it takes about 10s to switch off by itself.

I've gone back to electric since reading about the deadly fumes from the gas hob and their effect on my health

mmmmikey

Just a quick aside whilst we're discussing kettle costs.

I have about 7 hot drinks per day at 300ml each = 2100ml per day. Using the above figures for electricity that equates to 2100/400*55 or about 0.3kWh per day. Which is about the same as my fridge or internet router......

ariarnia

mmmmikey said:

Just a quick aside whilst we're discussing kettle costs.

I have about 7 hot drinks per day at 300ml each = 2100ml per day. Using the above figures for electricity that equates to 2100/400*55 or about 0.3kWh per day. Which is about the same as my fridge or internet router......

do you think boiling less but bigger cups of water would make a difference? i know its a fixed amount of energy to heat a fixed amount of water 1 degree but is there a difference in heat loss if you boil 500ml versis 300? 

if so you could save by switching to a sports direct mug maybe? and less steps to the kitchen and back!

mmmmikey

ariarnia said:

do you think boiling less but bigger cups of water would make a difference? i know its a fixed amount of energy to heat a fixed amount of water 1 degree but is there a difference in heat loss if you boil 500ml versis 300? 

if so you could save by switching to a sports direct mug maybe? and less steps to the kitchen and back!

In the interests of science, I'll try tomorrow whilst I have the bits and pieces to hand and post an update. Having said that, the costs I gave are the EPG standard rates which I used for comparison because they're most relevant to most people. I actually pay 6.9p/KWh because I buy my electricity overnight at E7 rates and store it in a battery. There are some efficiency losses so it probably costs me about 10p/Kwh = 3p/day or about £11 per year - a price well worth paying to feed my tea addiction