Why cant we use small transformers in electric transmission?
Any transformer wastes a small portion of the power that goes through it. At a power station, large amounts of power are going through them. Therefore, the small portion is a fairly large amount of heat which has to be radiated off or otherwise removed. And the transformer has to be designed to not over heat in the midst of the hottest days of summer, when it is most needed for air conditioning, which is also when it is hardest to cool the unit so it must have considerable volume with lots of surface area to get air flow to cool it down.
