Boiling water

Rann23

the kettle vs microwave comparison was helpful but does anyone know how stove-top kettle on an induction hob compares?

Netexporter

Induction and electric kettle will be about the same. There is very little very little heat "spillage" from an induction hob, so it is probably more efficient than a kettle on a gas hob. 

MultiFuelBurner

https://www.youtube.com/watch?v=_yMMTVVJI4c

ArbitraryRandom

Netexporter said:

Induction and electric kettle will be about the same. There is very little very little heat "spillage" from an induction hob, so it is probably more efficient than a kettle on a gas hob. 

The only difference I can see is the conductive properties of the kettle - meaning it will take a little longer to heat and retain more heat than a plastic kettle... assuming that the kettles are otherwise of the same size and the volume of water heated remains the same (and, of course, a spherical cow in a vacuum ), I agree any difference will be negligible. 

MikeJXE

I did a stove top kettle on gas  v electric kettle 

1 Cup took 1 minute on electric and 1 cup on gas took 2 minutes so gas is the cheapest of the two 

Netexporter

What was the kW rating of the gas burner?

UnderTheCarpet

I've tested boiling 400ml of water in a stove top kettle, on my gas hob, a portable induction hob and a portable ceramic hotplate. I used the same kettle throughout, stopping the test when the kettle whistled.

Please check my work! It's been years since I sat in science class. 😂

Gas hob: according to the manufacturer, the auxiliary burner is rated at 1kw. It's the smallest burner, chosen to reduce heat loss up the sides of the kettle. It took 5m 12s to boil. According to my maths, that's about 83w. Gas is 7p/kwh, I make this about 0.6p to boil.

Portable induction hob: I used a P110 energy monitor this time. According to that, it took 53w. Electric is 27p/kwh, I make this about 1.35p to boil.

Portable ceramic hotplate: I used the same P110 device, this took nearly 150w to boil the kettle. This is partially because the hotplate is wider than the base of the kettle. I don't use this hotplate at all now I have the induction hob. It took longer and wasted more energy to boil the kettle. I only tried it for the sake of this experiment.

Conclusion: in my kitchen, using gas works out much cheaper. It's more cost efficient, but lower in energy and time efficiency. The heating vessel also matters - having a larger based vessel would have made the ceramic hotplate less inefficient. I doubt it would put it on par with an induction hob, as it was still quite warm several minutes after removing the kettle and being turned off.

Gerry1

UnderTheCarpet said

Please check my work! It's been years since I sat in science class. 😂

You seem to be stating watts when you mean watt hours, and it's Electricity not Electric.

Petriix

I use my gas hob unless there's enough solar export to cover at least half of the 2kW required to power the electric kettle. Gas is around 1/4 of the cost of peak electricity so (at worst) potentially wasting 50% of the energy still makes it half the cost. In the winter the excess heat isn't wasted because it heats the house usefully. 

ArbitraryRandom

UnderTheCarpet said:

It took longer and wasted more energy to boil the kettle. I only tried it for the sake of this experiment.

Thanks, that's interesting - especially the difference between the two electric methods. I guess that's mostly showing the losses caused by an incorrectly sized ring (and as you say the residual heat).

The only criticism I would make would be that the manufacturers rating doesn't accurately tell you how much gas (how many kWh) you were actually using during the test, because it will have been measured in specific lab conditions with a known gas mix - but that's me being pedantic; it's probably the best you can do in a domestic environment and your margin for error (the actual difference in cost) means it's unlikely to significantly alter the result. 

I also feel compelled to note that obviously no heat is 'wasted' in winter given you would be otherwise heating the house (slightly more)  

Netexporter

I'd still have an induction hob, rather than a gas hob, any day of the week, because you aren't filling the kitchen with noxious fumes.