The Grid: Electrical Infrastructure for a New Era

by Gretchen Bakke

The singular advantage of alternating current is that low voltages, made at the generator, can be “stepped up” to much higher voltages by means of a transformer—a simple device made of two sets of tightly coiled copper wires that almost, but don’t quite, touch. Higher voltages can go farther than lower voltages. It has, if you will, a higher quotient of desire, it “wants” harder, and thus is propelled farther. The transformer is a simple if genius means by which this “stepping up” and “stepping down” of voltage is accomplished without any loss in efficiency. It only works, however, if the current traveling through it “alternates,” which is to say, moves in a series of rapidly reversing waves.