Is my understanding correct that if the supplied voltage to appliances are lessened, would that mean that the power consumption would also decrease? Like I have an Electric stove at 3000W at 220V, what would it's power consumption be at 180V? Would this mean that the output heat of the stove would decrease? Would it hold true for other appliances in the house?
I think, yes, it works that way. Power = CurrentxVoltage, if the stove is purely resistive, following that, at 180V the power should be around 2000W. It would just mean that it would take longer to heat up to a certain temperature.