New tidal generator could mean cheaper electricity

Researchers at the University of Southampton have developed a new kind of marine generator they say could substantially reduce the cost of electricity generated from tidal power.

Dr Steve Turnock said the design was a new take on tidal energy generation: "This is a compact design that does away with many of the moving parts found in current marine turbines."

The principle of tidal power generation is simple enough: water flows over a propeller causing it to turn. This spins a shaft that is connected to a generator which in turn, generates electricity. However, normal tidal turbines are complex pieces of kit, with lots of gears, and other moving parts that need maintaining and replacing over time.

Because this new design will generate electricity whichever direction water flows through it, it has fewer parts than many turbines currently in use. This makes its build cost much lower, and reduces expensive underwater maintenance. It also means less downtime, since the generators don't need to be moved to face the direction of the tidal flow.

The prototype is also designed so that all the components are in a single package. This would make it much cheaper and easier to install, the researchers argue.

Although the current prototype is just 25cm across, the team is working on a larger version which it says will have even better propellers. It is optimistic that the design will be commercially available within five years. ®