In association with Oxford University’s Department of Engineering Science, UK-based Kepler Energy has developed Transverse Horizontal Axis Water Turbine (THAWT) technology, which can generate tidal energy in shallow water.

The horizontal axis turbine can be economically installed underwater at depths of up to 30m.

Once operational, it can eliminate expensive set-ups of large dams and barrages, and reduce unpredictability of the results, reports Reuters.

Testing of the second-generation tidal turbine has indicated that it has a higher potential than existing axial flow designs.

THAWT is equipped with carbon composite hydrofoil blades, and has been designed for use in shallower, lower velocity tidal waters, unlike convention propeller-type turbines, which have large blades that limit their deployment to waters of at least 30m-deep.

The design is claimed to be a modified version of the vertical Darrieus wind turbine.

Oxford University civil engineering professor Guy Houlsby was quoted by the news agency as saying: “The original Darrieus turbine has blades that are parallel to the axis of rotation, and that means that the loads in the blades are carried entirely by bending of the blades.

“That results in very high stresses.

“The re-design that we’ve done changes the blades so that they form this triangulated structure, and that’s a very stiff and very strong structural form. And that means that the loads in the blades are principally carried by axial forces and that means that the stresses are much lower.”

According to Kepler Energy, the turbine design has minimal moving parts in the water, with the majority of its parts being installed in dry columns, such as the generator and other electrical equipment.

Generating units of THAWT include two sets of blades set on three columns, with a single generator between them.