HTS for PowerBuoy

Ocean Power Technologies (OPT) and Converteam have signed an agreement to develop high temperature superconductor (HTS) linear generators for use in OPT’s PowerBuoy wave energy converters.

Under the agreement OPT and Converteam will jointly develop the technology on an exclusive basis for at least five years. During this time the companies will explore commercial opportunities and potential customers for the HTS linear generator PowerBuoys.

OPT is a wave energy technology developer with PowerBuoy projects in Spain, the UK and the US. Customers and partners include Iberdrola, TOTAL and the US Navy.

Converteam is also a supplier to the US Navy, renewables, marine and industrial markets, specialising in the development, design and supply of electrical motors and generators, power converters and cryogenic systems.

The proposed power take-off for the OPT PowerBuoy will employ Converteam’s proprietary linear generator system with high temperature superconductors to provide the magnetic field.

The companies expect to convert the linear up and down motion of waves into electricity using OPT’s PowerBuoy and Converteam’s HTS linear generator. This system is expected to have the advantage of improved efficiency, reliability and maintainability over traditional power take-off or linear permanent magnet based systems.

Life cost analysis is said to predict that the use of high temperature superconductors provides the necessary magnetic field at much lower cost and weight than conventional linear permanent magnet generators.

‘HTS offers a linear generator of unprecedented power density and efficiency enabling significantly more energy to be converted to electrical power,’ said Converteam technology director, Derek Grieve.

‘Converteam already has ongoing HTS projects in hydro, marine and wind. These are all migrating to second generation HTS wire which has a much higher flux density, lower cost and operates at higher temperatures than first generation wires allowing the use of a cheap coolant medium. HTS is a truly disruptive technology the advantages of which will radically change wave energy capture.’