The University of Oxford Department of Engineering Science, in conjunction with Kepler Energy, has developed a new horizontal axis tidal turbine that can operate in lower velocity tidal waters.
The Kepler Transverse Horizontal Axis Water Turbine (THAWT) is designed to be operated either in arrays or in stand-alone form.
The carbon blades of the turbine are configured in a way that doesn’t require the turbine rotor, called a triangulated stressed truss, to have an enveloping supporting structure.
This leads to lower parasitic drag, and hence low power losses, according to Kepler Energy.
The basic generating unit comprises two rotors with a central generator, with four supporting bearings and three foundation supports required.
The turbine is scalable to suit different marine sites, and has been designed for resources in shallower, low tidal stream velocity flows.
Kepler Energy states that a typical turbine rotor would be 10 m diameter and 60 m long sited in a tidal flow with a mean depth of 20 m.
Documented flume tests on a scale model have shown that the basic 10m diameter, 120 m long unit, consisting of two turbines with one generator, should generate more than 4.4 MW at a water velocity of 2 m/s, and more than 5.2 MW at a water velocity of 2.5 m/s, according to Kepler Energy.
To remind, Kepler Energy has announced tidal energy fence project that would feature THAWT technology and would be located in Bristol Channel, UK.
A tidal fence envisages a linear, connected series of turbines in a chain, placed to best exploit the available tidal flow.
The 30 MW tidal fence deployment will be subject to detailed environment and technical assessments to ensure that it safely co-exists with marine life and other users of the sea.
Take a look at the video of the scaled THAWT turbine testing.
Source/Images: Kepler Energy