Harnessing the power of rivers and tides
Researchers from the University of Southampton are developing a renewable energy scheme using water-powered generators.
Thanks to commercial backing from private investors, Dr Suleiman Sharkh and Dr Stephen Turnock from the University’s School of Engineering Sciences are working alongside Hampshire-based engineering company TSL Technology Ltd, to build and assess a prototype generator.
The generator began life as an electric motor for rim-driven thrusters, which are used on tethered underwater vehicles. The academics saw the potential to run this backwards as a generator, instead of using electricity to turn the propellers and drive the vehicle along, the flow of water turns the propellers, generating electricity.
What’s unique about the design is its simplicity and compact rim-driven design without a gearbox. Additionally, thanks to symmetrical blades and duct designs, the device is bi-directional, saving the cost of a turning mechanism to change the orientation of the device if the flow of water reverses. All of this makes the design potentially more robust and cost-effective for energy consumers.
Dr Turnock says:
“The challenge is to develop technology that is rugged and reliable but still cost-effective for electricity generation. This new investment will allow us to take the tidal generator to the next level of realisation. The rim-driven generator will work most effectively in fast-flowing, shallow water, and an array of these devices could provide a locally generated and sustainable energy source for riverside and coastal communities.”
If the prototype proves economically and technically viable, the team envisage a 10-50kW generator becoming commercially available within the next three years.
The generator has received worldwide interest from communities in New Zealand, Canada, Central America and more recently a town of 600 in Alaska who live alongside a wide, fast-flowing river driven by glacier meltwaters.
More locally, a similar generator was used in a pilot study in the summer of 2007 under Yarmouth Pier on the Isle of Wight to see if the site is suitable for capturing energy from the tide. The 1.2m diameter turbine was installed underneath the Pier to assess how much power can be generated from the tidal flow and to investigate the practical issues of leaving such a device in the water for a long period.