Electricity Cost Versus Gas Camping Canister Cost.

Butane is about 13,640 Wh per kg.


So your 227g can will be around 3kWh assuming the combustion liberates all that energy.

EDIT It looks like the catalytic heaters are very efficient at extracting energy, so about 3kWh per can. We're not in the UK (it's a balmy 30C here in Bangkok) so I can't compare with the cost of power there.

You won't stay very warm with a heater like that Zoom, and if it is cold it will freeze the gas solid, so not much use! 47kg propane are much better with a nice big heater. Propane will work ok to at least -20C.

In the longer term, electricity from the mains is going to be a bit cheaper in price compared to the butane cylinder, but if you had it, then methane from the gas mains in the street would be cheaper still.

In metric units all the hydrocarbons end up being 48-50  Megajoules per kilo. Although propane and methane are smaller molecules than butane, and you get less energy per molecule from burning, this is almost perfectly compensated by the fact you get more molecules per kilo of the smaller molecules.


A megajoule is not that much - a kilowatt for a thousand seconds, so the l kilo of the gas will be 50 000 000joules / 3600 seconds per hour, or as per Crossy above, 13800 watt hours, or 13.8kWhrs per kilo.

your can will be


so 14 units of electric per kilo, but that is 4 cans  at £1 each - call it £4/14  =  28 p per  unit. Somewhere above day rate.


It is cheaper to buy bigger bottles of propane, but you need a different type of burner.. (well maybe not, I have used butane boiling  rings on propane in the past, just adjusting the air flow for a non yellow tipped flame.)


Do take care with camping stoves indoors - they are built to a value engineered standard that assumes use in a  well ventilated outdoors, and small leaks are not uncommon.


I've seen the odd one go up with Scouts (who are very rough with them however), and it can be scary, I'd hate anything like that to be indoors.


For keeping warm, really, 100m thick celotex slabs are your friend.


Mike.

Thanks Mike for your very useful and detailed answer to my question.


Z.