New power storage method uses ABB motor 11 February 2011

A revolutionary new way of storing electric power, developed by Highview Power Storage, uses a cryogenic process to store energy.

Dubbed CryoEnergy, the system works by using cheap rate electricity to operate an air liquefaction plant – then storing the liquefied air in an insulated tank at -196C.

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

Says Highview Power Storage CEO Gareth Brett: "With the drive for a low carbon economy, there is increasing emphasis on wind and solar sources. However, by their nature, these forms of generation are intermittent, and there is thus a need for a viable energy storage method to act as a buffer."

The generation stage is accomplished by an ABB motor, which, in a pilot plant currently being hosted by Scottish and Southern Energy, is a 500kW induction motor deemed large enough to supply electricity to several hundred homes.

"The application required the use of an induction motor as a generator, so a simple robust machine was required with no special starting or cooling requirements. The ABB range offered us exactly what we needed," comments Brett.

ABB supported development of the application with advice about the motor's operation. "Our prime mover is very sensitive to torque transients as well as speed excursions," explains Brett. "ABB were able to provide transient torque plots under fault conditions, as well as the torque speed relationship at a part of the curve that would not normally be looked at for a motor application."

Highview now plans to scale the system up to the 3—5MW range. "We will probably need to change to a synchronous generator and, based on past performance, we will certainly be talking to ABB about that scope of supply," says Brett.

Brian Tinham

Related Companies
ABB Ltd

This material is protected by MA Business copyright
See Terms and Conditions.
One-off usage is permitted but bulk copying is not.
For multiple copies contact the sales team.