For AC power, capacitors don’t effectively store energy for later, and would change the power factor to make the resistive load reactive which can bring down the efficiency of the power transfer. For AC power a big ol resistive heater is probably as efficient as you can get, which is part of why those kettles are so simple and boil water so fast.
A kettle that stores energy would need to use DC power, converting it from AC and probably have a very large capacitor, more likely a battery.
For AC power, capacitors don’t effectively store energy for later, and would change the power factor to make the resistive load reactive which can bring down the efficiency of the power transfer. For AC power a big ol resistive heater is probably as efficient as you can get, which is part of why those kettles are so simple and boil water so fast.
A kettle that stores energy would need to use DC power, converting it from AC and probably have a very large capacitor, more likely a battery.
Let’s make it even MORE complicated. Let’s make the kettle a heat pump powered by a bank of supercapacitors!