This data-file estimates the efficiency of electric motors and power generators, using specific examples and data-points.
This matters as there are around 50bn motors in the world, consuming c45% of global electricity.
Efficiency ratings are generally high, above 90%, although lagging and non-optimized motors can be in the 70-80% range, suggesting huge scope for improvement.
Power generators are effectively just motors wired in reverse. Notes on the functioning and efficiency of motors follow in the final tab .