If a potential difference exists, then energy can be extracted. Property of material that helps prevent the flow of electrons in it. Metals are good conductors due to low resistance. Wood is a poor conductor due to high resistance. Resistance, R , is measured in ohms and depends upon both the type of material and its size.
R is also temperature dependent.
We can control this buy putting the right resistance in the circuit for a given battery Voltage. This is a linear relation. Standard US household voltages in an outlet is 120 Volts. Your electricity bill essentially measures the amount of current that you use but you use this current as Power . To cook your food you need to have so much power radiated by the stove.