Schottel creates hydrokinetics subsidiary

Triton semi-submerged floating platform

NOVEMBER 7, 2014 — Spay, Germany, headquartered marine propulsion specialist Schottel has created a new subsidiary to handle its hydrokinetic energy business, Schottel Hydro GmbH.

The new company will be active in three segments: hydrokinetic turbines, semi-submerged platforms and components, such as turbine hubs and drives.

“We have been working on the development of highly efficient, reliable and cost-effective solutions for gaining instream energy for several years,” says Schottel CEO Prof. Dr. Gerhard Jensen. “Schottel Hydro allows us to dedicate even more to hydrokinetic energy solutions. By now we are involved in projects around the world and aim at a full penetration of the emerging hydrokinetic energy market with our solutions and products.”

Hydrokinetic turbines

Schottel hydrokinetic turbines are lightweight, yet robust instream generators, with a rotor diameter between three and five meters. Depending on the current velocity, one turbine produces between 54 and 70 kW rated, grid-ready electric power. Higher power demands are met by combining several turbines in one installation. Each of the turbines is connected to a frequency converter feeding into a common DC bus installed on the tidal platform. The turbines can be implemented in rivers, sea straits and tidal races offshore in jetty, semi-submerged or submerged platforms in varying numbers. Even installation at sites with restricted water depth is possible thaks to the small size of the turbines.

Turbine carrier platforms

Together with subsidiary TidalStream Ltd., Schottel Hydro offers the Triton semi-submerged floating platform. Triton platforms can be adapted to host turbines of different designs and sizes. Effective use of tidal energy in water depth up to 90 meters and a generating power of up to 10 MW in a single installation are feasible.

The platform is attached to a gravity-base, drilled pile or pinned frame anchor point. A universal joint allows the platform to align to the direction of the flow. Buoyancy is provided by two spar buoys which hold a variable number of cross arms. The turbines are mounted on the cross arms. The platform is particularly maintenance friendly: The electronic system is accessible in the spar buoys and by emptying or filling of ballast tanks the platform easily switches between operating and maintenance position. This platform will be installed in 2016 in the Bay of Fundy, Canada.

Turbine components

Schottel Hydro can draw on 60 years of Schottel experience in the design and production of underwater equipment and offers high quality engineering and manufacturing for in-stream power solutions, e.g. gear boxes, shafts, sealing systems, hub and pitch mechanisms for tidal turbines.

Schottel Hydro components can be found in the three-bladed Andritz-Hydro-Hammerfest HS 1000 turbine. Schottel provided the turbine shaft, shaft sealing, hub and pitch mechanism for this 1 MW tidal generator. The HS 1000 is designed for installation on the seabed at 40 to 100 meter depth in tidal streams. The pitching system allows optimal harnessing of tidal currents in both ebb and flood directions.