So I've seen a couple different threads on here where people wonder which is more efficient when it comes to heating water, etc.
I'd wondered the same thing myself and since I have an energy monitoring system on my house, a couple years ago I decided to measure the difference.
Note: the stove in question is one of the flat top types with the burners below a glass top. The kind with exposed coils will likely be somewhat more efficient. The kettle is the plastic kind with a metal heating plate on the bottom.
At any rate, the stove used almost twice as much energy as the kettle and it took 4 minutes longer (~8.5 minutes on the stove, ~4.5 minutes in the kettle):
My opinions are barely worth the paper they are written on here, but hopefully they can spark some new ideas, or at least a different train of thought