UK: SCHOTTEL Presents STG 50 at International Tidal Energy Summit

At the occasion of the International Tidal Energy Summit in November in London, SCHOTTEL presented the first SCHOTTEL TIDAL Generator (STG 50) to the public.

Optimum generator size

The SCHOTTEL Tidal Generator is a new approach on the market, focussing especially on high efficiency at relatively low investment and maintenance costs. STG 50 is the result of in depth research and test trials.

The light-weight and robust tidal generator is based on the fact that reducing turbine size leads to a better ratio of power and material use. High overall power can be reached with a higher number of turbines. STG 50 is a horizontal free flow turbine with a rotor diameter of 4.0 to 4.5 m and a rated power of 45 to 50 kW. It can easily be composed in arrays of various types and sizes depending on the available space and the output expectations.

Grid ready and tailored installations

The turbine is equipped with an asynchronous generator converting the variable rotation into electric power. Each of the turbines is connected to a frequency converter feeding into a common DC bus installed on the tidal platform. Finally a common frequency converter together with a large transformer is used to produce grid-ready electricity.

Thanks to the modular approach, STG 50 can be implemented in rivers, sea straits and offshore in jetty or floating platforms. The latter are developed by TidalStream Ltd. in which SCHOTTEL holds shares.

New developments based on experience

The name of SCHOTTEL traditionally stands for quality engineering in the maritime sector with over 90 years in design and precision workmanship. SCHOTTEL propulsion systems can be found all over the world in almost any kind of vessel. With this knowledge the STG turbine was designed with a focus on high efficiency with respect to both hydrodynamics and electrical components. Power train engineering too, was lead by the decades of experience with offshore propulsion systems combined with the latest design and simulation tools.

 Drive train and full-scale tests successfully finished

The turbine design has been supported by various model tests and RANS-CFD simulations. The drive train was subjected to extensive laboratory tests. Two complete STG drive trains were installed in a submerged back-to-back configuration. One was used as a motor driving the second which acted as a power generator.

Full-scale tests have been performed with the entire converter including the rotor. For this purpose, with the unit was fixed to a tug. This setup allowed for the adjustment of various flow conditions. Different sets of rotor blades as well as the entire power generation chain have successfully been tested.

Tidal energy – an economic contribution to the energy mix

Ocean energy from tidal and river currents is an attractive part of the future energy mix. It is a reliable, predictable and inexhaustible energy source. SCHOTTEL aims to make this energy source economically competitive with well established energy sources.

[mappress]
Press Release, February 21, 2013; Image: schottel