Using an Electric Tea Kettle to Save Propane ?

[StuM]

Originally Posted by sailorchic34

Propane has a heat rating of 21,600 btu's per pound of fuel (91,000 btu per gallon). It actually varies a bit from location to location. Butane is 21,300 btu per pound, which is pretty close to propane.

The typical galley stove burner is rated at 6500 or 7000 btuh. The energy required to heat one quart (~liter) of water from 45 degrees to 212 degrees is roughly 347 BTU's or 0.101 KWh.

The nitty gritty is a resistive immersion heating element will give you right near 100% eff. That is all the heat goes to the water. A kettle on the stove is probably only capturing 40% ( my WAG or wild a$$ guess of heat transfer efficiency) of the heat of the burner. It could be less then that, probably not much more. Most of it is going around the kettle, heating the stove top, etc.

So right off the top, the propane will need about 868 BTU's per quart (~liter), which with propane being $3.50 a gallon here would be roughly 3.48 cents of propane.

Electrical cost in California at 0.16 cents per kw would be 1.61 cents if your paying for electric use. Of course an electric stove would have similar efficiency's of a gas stove. So if your heating the kettle on an electric stove the cost rises to 13.8 cents (ouch).

But a kettle with an immersion heating coil would be very efficient.

Absolutely spot on!