Compact Underwater Turbine

Julie Kalista
Online Editor

The minimal components of the integrated electric generator.

The tested prototype.

Researchers at the University of Southampton turned an electric motor upside down to create a more efficient generator. The idea came from their tethered underwater vehicle with much smaller and more powerful electric thrusters for propulsion, with the new generator made from its electric motor.

Most current tidal stream generators are just wind turbines that work underwater. The new generator eliminates complex gearboxes used in current marine turbines, the parts that often require expensive maintenance. Because it requires less power it is also cheaper to run. Turbine blades work equally well no matter what direction water flows past them so there is no need to turn to face the direction of the current, according to the team.

"Just drop the generator into flowing water and it will start generating electricity," says one of the researchers. "It works best in fast flowing, shallow water." The current prototype is 25-cm. across but the team has plans to build a larger model with improved propellers to increase efficiency.
The team hopes the generator will
be commercially available within five years.

More Information:
University of Southampton

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