Making appliances—and energy grids—more efficient

Conserving energy with the ideal ceiling fan

The base shown here contains the motor and the power electronics being tested.Credit: Tata Center for Technology and Design

If every fan in India saved just two watts of electricity, that would be the equivalent of a nuclear power plant’s generation capacity.

James Kirtley

The ceiling fan is an appliance ubiquitous across the world—and it’s also highly inefficient. Determined to offer high efficiency at an affordable cost, MIT researchers are developing a single-phase motor design by using power electronics to optimize the flow of electricity through the motor. They are experimenting with two approaches: creating an improved version of the conventional induction motor, or switching to a brushless DC motor, which may be more expensive but can deliver superior efficiency. The brushless DC motor uses permanent magnets to establish a magnetic field that creates torque between the motor’s two main components, the rotor and stator. Induction motors, without using magnets, create a rotating magnetic field by sending current through the stator coils. The research process has also included conversations with people across the ceiling fan industry in Mumbai, leading to key insights on common maintenance issues. Ultimately, the more efficient and cost-effective motor will have applications for any number of common appliances.