Originally Posted by ajdelange
Your belief flies in the face of physics as it does not include the amount of energy being delivered to the water/wort. If, in a boiling kettle, you double the energy per unit time (power) delivered to the kettle by switching on a second element, increasing the gas flow to a burner, increasing the amount of steam delivered to a jacket or whatever where can that energy go? It cannot go into increasing the temperature or pressure in a vessel open to the atmosphere (though it can in an enclosed boiler e.g. a pressure cooker). It cannot be lost through the sides of the vessel as the heat loss there is proportional to temperature and the temperature is fixed (though in an improperly skirted gas system some of the heat from the bigger flame would be lost). It can't go into the creation of mass. The only place that energy can go is to increased rate of vaporization. I don't see how you could have failed to observe that if you put a pot on the stove it boils more vigorously when you turn up the heat. Same surface area - more steam production.
If that was directed at me, of course you are correct. I was trying to point out that with everything else held constant, the boil-off rate is a function of the open surface area. I failed to explicitly point out that the heat applied must also be held constant. Holding that constant is much easier with electric than propane, lol. I will edit the post accordingly.