US wave developer Columbia Power has received its first European patent for its Stingray device.

The patent covers the wave energy converter’s direct drive power take-off.

The Stingray uses two floats to capture wave energy and two rotary permanent-magnet generators to convert the energy into electricity.

Each float is directly coupled to its own generator, which enables a single energy-capture/conversion cycle.

A land-based test of the generator and air-gap control system is currently underway at the National Wind Technology Center in Colorado.

The rotary generator has a diameter of over 6m with a 4mm rotor-stator air-gap.

A large-scale Stingray will be deployed at the US Navy’s Wave Energy Test Site in Hawaii next year.

Image: Stingray wave device (InterMoor)