Motor aids power storage

A new way of storing electric power is using ABB motors as a generator.

Developed by Highview Power Storage, the Highview CryoEnergy System uses a cryogenic process to store energy. The system works by taking in cheap rate electricity and using it to operate an air liquefaction plant, storing liquefied air in an insulated tank at -196°C.

When the stored energy is needed, liquefied air or liquid nitrogen is released from the tank, pumped to a high pressure and allowed to warm and expand to gaseous state. High pressure air is used to drive an expansion turbine, which turns an ABB motor acting as a generator.

The ABB motor, in a pilot plant hosted by Scottish and Southern Energy, is a 500kW induction motor.

This is large enough to supply electricity to several hundred homes.

Gareth Brett, CEO, Highview Power Storage, says: "ABB provided transient torque plots under fault conditions, as well as the torque speed relationship at a part of the curve which would not normally be looked at for a motor application."