I know they use transformers on power polls and transformer stations along the power line grid to boost the electricity along the way. I was wondering if it's possible to use a transformer/s between the wall socket and electrical device to reduce electrical consumption from the grid while still supplying enough wattage to run the device. Or will the transformer just increase voltage while consuming wattage?
An example of what I mean is a 500 watt window AC unit running 24 hours a day will cost $1.20 a day to run (using the national average of 10 cents per kilowatt hr), $36 a month. Would it be possible to use a transformer between the AC unit and wall outlet to reduce the actual wattage consumed from the grid, while still being able to supply 500 watts the AC unit consumes?
If so, that could reduce the actual electrical cost of heating and cooling devices, as well as artificial light fixtures by reducing the wattage consumed from the grid.