Compact tidal generator could reduce the cost of producing electricity from flowing water

Jun 13, 2006

What happens if you run an electric motor backwards? That is exactly what researchers Dr Steve Turnock and Dr Suleiman Abu-Sharkh from the University of Southampton asked themselves after they had successfully built an electric motor for tethered underwater vehicles, using funding from the Engineering and Physical Sciences Research Council.

The well-known answer to this question is that it stops being a motor and becomes a generator. Instead of using electricity to turn a propeller and drive the vehicle along, the flow of water turns the propeller, generating electricity. What's new about the Southampton design is its simplicity. "This is a compact design that does away with many of the moving parts found in current marine turbines. It's a new take on tidal energy generation," says Turnock.

Most current tidal stream generators are essentially wind turbines turned upside down and made to work underwater. They often include complex gearboxes and move the entire assembly to face the flow of the water. For example, they turn a half a circle as the tidal current reverses direction. Gears and moving parts require expensive maintenance, especially when they are used underwater. This pushes up the cost of running the turbines, a cost that is passed on to the consumers of the generated electricity. The Southampton design does not need to turn around because the design of its turbine blades means that they turn equally well, regardless of which way the water flows past them. The blades are also placed in a specially shaped housing that helps channel the water smoothly through the turbine.

Another beauty of the Southampton design is that everything is wrapped in a single package that can be prefabricated so there will be few on-site construction costs. "Just drop it into flowing water and it will start generating electricity. It will work best in fast flowing, shallow water," says Turnock, who foresees rows of these devices secured to sea floors and riverbeds.

The present prototype is just twenty-five centimetres across and the research team now plan to design a larger model with improved propeller blades that will further increase the efficiency of generating electricity. All being well, the team envisage the generator becoming commercially available within five years.

Source: Engineering and Physical Sciences Research Council

Explore further: LiquidPiston unveils quiet X Mini engine prototype

add to favorites email to friend print save as pdf

Related Stories

Tomorrow's degradable electronics

Nov 20, 2014

When the FM frequencies are removed in Norway in 2017, all old-fashioned radios will become obsolete, leaving the biggest collection of redundant electronics ever seen – a mountain of waste weighing something ...

Water bottle for bike collects moisture from the air

Nov 18, 2014

Kristof Retezár, an Austrian designer, has come up with Fontus, which was designed as a self-filling water bottle for your bicycle. This device collects the moisture from the air, condenses it and stores ...

Testing turbines to save energy

Nov 18, 2014

They say a little knowledge is a dangerous thing. But a little knowledge can also be comforting. For anyone who has sat on a jet airplane at takeoff, tense and sweaty-palmed, wondering how in the world this ...

October was 'bumper' month for Scotland's renewables

Nov 07, 2014

Any way you look at it— the solar PV panels, the solar hot water panels, the wind turbines—Scotland turned out to have a bumper month for renewables in October. Wind turbines generated an estimated 982,842MWh ...

Recommended for you

LiquidPiston unveils quiet X Mini engine prototype

Nov 21, 2014

LiquidPiston has a new X Mini engine which is a small 70 cubic centimeter gasoline powered "prototype. This is a quiet, four-stroke engine with near-zero vibration. The company said it can bring improvements ...

Novel robotic walker helps patients regain natural gait

Nov 21, 2014

Survivors of stroke or other neurological conditions such as spinal cord injuries, traumatic brain injuries and Parkinson's disease often struggle with mobility. To regain their motor functions, these patients ...

Tomorrow's degradable electronics

Nov 20, 2014

When the FM frequencies are removed in Norway in 2017, all old-fashioned radios will become obsolete, leaving the biggest collection of redundant electronics ever seen – a mountain of waste weighing something ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.