Electric motors consume 64% of the electric power generated in the United State, with about half of this amount used by large motors (greater than 100 hp or 75 kW power). The efficiency of the average motor is 92%, and that of large motors about 96%. Conventional electric motors have reached their optimum in terms of power density and efficiency, and only the application of new materials can lead to further improvements. Superconductors offer the ability to carry very high direct electric current density without losses, and rotating apparatus (motors and generators) represent some of the most promising applications for superconductivity.