World statistics show that around 30 million tons of oil equivalent (MTOE) of primary energy is consumed per day by mankind, nearly one-third of which is devoted to generating electricity. Over half of all the electricity in the world is consumed by electric motors. Combined, electric motors consume greater than 10,000 trillion watt-hours (TWh for terawatts) of energy each year. Electric motors power our homes, offices, plants and factories - machines, pumps, fans, air conditioning, refrigeration, robots, data storage, electronics, etc. In the future, new massive demand will come from electric vehicles, and will continue to grow as electrification takes to the air and other mobility platforms throughout society.
Electrical machines have an enormous influence on the management and reduction of energy consumption. Just today, with over half of the world’s electricity eventually flowing through an electric motor, decisive gains in power and efficiency will have untold benefits in terms of performance, energy savings, and the environment. It has been estimated that in developed countries today, roughly 20% of electrical energy can be saved by using more efficient motors and control strategies for electromechanical drives. A 3% increase in motor efficiency, for example, can translate to 2% savings for all energy being consumed overall. Improving the energy efficiency of the world’s electric motors by just 1/10th would save enough electricity to run the entire country of Japan for an entire year, dramatically reducing the world’s carbon footprint and cutting harmful CO2 emissions by more than a billion tons.
Now imagine the technology to make electric motors more efficient is already here: Nd-Fe-B magnets. Most energy is consumed by three-phase induction motors rated at below 10 kW. Consider a small three-phase, four-pole, 1.5-kW, 50-H~cage induction motor. The full load efficiency of such a motor is usually 75%. By replacing this motor with a Nd-Fe-B magnet motor, the efficiency can be increased to >90%. This means that the three-phase Nd-Fe-B motor draws from the mains only 1700 W instead of 2000 W drawn by the three-phase cage induction motor. The power saving is 300 W per motor. If in a country, say, one million such motors are installed, the reduction in power consumption will be 300 MW; or, in other words, one full-scale turboalternator can be disconnected from the power grid.
The latest designs are extremely efficient: some large electric motors using Nd-Fe-B magnets can now turn 97-98% of the electricity input into mechanical energy output. Even the best internal-combustion engines can manage only about 45%. Small gains in efficiency mean big savings in cost. The cost of an electric motor and its drive represents less than 1-1.5% of the cost of the electricity it will consume over a 20-year operating lifetime.