Regenerative drives represent one of the most significant innovations in the latest generation of energy-efficient elevator technology. When an elevator goes up with a light load and down with a heavy load, the system generates more power than it uses. That power is lost as heat in traditional elevator drives, wasting substantial amounts of energy over the life of the elevator. Regenerative drives capture the heat generated by elevators during use and convert it into reusable energy for the building rather than wasting it as heat.
When power flows into the elevator motor, it creates a lifting torque on the shaft and elevator sheave, lifting the cab. When the cab travels down, the motor acts as a generator, transforming mechanical power into electrical power and pumping current back into the facility's electrical grid where it can be reused by another elevator or to power other electrical loads.
Over time these small amounts of power generated during the deceleration of each elevator add up to noticeable savings. Regenerative drives can reduce the energy consumed by building transportation systems by up to 70% and can even reduce the strain and cost of the HVAC system by eliminating excess heat in the building.