A little background; the line voltage supplied here in my part of India varies as a function of the load. At dusk, the measured value is as high as 248V. Household appliances are rated at either 220V, or 240V.
A friend and I were talking; my take is the bill is for Energy (kWH). Ergo, regardless of whether the line is 220, 240, 250 - the energy consumed will be constant. His take is that the higher voltage means a lower current drawn - less heat, and less energy consumed.
How do I, as a consumer, gain or lose when the utility line voltage swings above or below the rated value?