Electrifying the World: Faraday, Edison and Tesla

Electricity became a practical source of power in the late 19th century. In 1831 Michael Faraday discovered electromagnetic induction, the principle behind generators and motors. Improved dynamos from the 1860s made it possible to generate electricity on a large scale. In 1879 Thomas Edison and, independently, Joseph Swan in Britain produced practical incandescent light bulbs, and in 1882 Edison opened the Pearl Street Station in New York, an early central power station supplying direct current.

Nikola Tesla and George Westinghouse promoted alternating current, which could be transmitted more efficiently over long distances, and in the 'war of the currents' AC largely won. Electricity powered lights, trams, motors and new industries, and it allowed factories to replace central steam engines and belts with individual electric motors. Historians note that the full productivity gains from electrification took decades to arrive.