That said, does anyone know if it takes more electricity
to reheat water than to maintain it at a given temperature?
How long is a piece of string? It depends on how quickly your kettle loses heat, how warm the room is, and how long the interval between pours is. I have a generic Japanese thermos kettle, with vacuum insulated walls, so it holds heat fairly well.
It should be pretty easy to figure out precisely what the tradeoff point is with a datalogger and a thermocouple and some math, or a clamp ammeter and slightly less math.
It should be pretty easy to figure out precisely what the tradeoff point is with a datalogger and a thermocouple and some math, or a clamp ammeter and slightly less math.