Tidal current power stations

Tidal current power stations

Voith Hydro Ocean Current Technologies, Heidenheim, is a Center of Competence for the development of ocean current power stations (tidal and permanent currents). Voith Hydro Ocean Current Technologies is an 80:20 joint venture with the RWE Innogy Venture Capital Fund1.

Technology: Freely flowing around the horizontal axis turbine

The kinetic energy from ocean currents (tidal or permanent currents) is transformed into electrical power using freely flowing, three-bladed horizontal axis turbines.
Because of their similar physical properties, sea current turbines are similar to wind power turbines. However, since water as their driving medium has an 800 times higher mass density than air, they are equipped with much shorter rotor blades.
In order to meet the special requirements as regards installation and maintenance, the tidal current turbine from Voith differs significantly from a wind turbine in terms of its interior. The system is particularly simple, sturdy and low-maintenance. A deliberate effort was made to avoid using any high-maintenance elements, such as blade angle adjustment, current tracking, gears, dynamic seals, electrical simulation and lubrication of the bearings, etc.
For applications in tidal currents, where the direction of flow is changed every six hours, rotor blades are used which operate from both sides. Thus, the turbine changes the direction of rotation at each tidal change.

Contact

Hannes Hornung

Business Development Manager
Voith Hydro Global

Telephone
Telephone: +49 7321 37 9684

Test power stations

110 kW test power station in Korea

Since 2011, a first test turbine has been in operation near the South Korean island of Jindo. This test facility was built as a 1:3 scale model and is used primarily to demonstrate the new technology developments under real operating conditions. The turbine has a rotor diameter of 5.3 m, and achieves a rated capacity of 110 kW with a current speed of 2.9 m/s.
The test power plant fully meets the expectations of Voith's engineers. The calculated power curves have been confirmed. In addition, the system is able to keep the turbine running at the optimum power generation point at all times, even in the exceptionally turbulent currents that occur at this location.
The Jindo power plant stands on a gravity base foundation due solely to its intrinsic weight. For recovery during maintenance, a special recovery module on a drive chain slides down to the turbine nacelle, grasps it from below and then lifts it out of the gravity structure. The nacelle is then lifted by winding up the guide chains to the water surface

1MW test power station at the European Marine Energy Center (EMEC) in Scotland

The construction of a full-size machine and the installation of a 1 MW turbine in EMEC was the consequent continuation of our test program. It allows the low-maintenance current turbine systems to be developed in a commercial size.

With the exception of a number of small modifications, the EMEC turbine is basically an up-scaled version of the system in Jindo. The simplicity and sturdiness of the optimized system has been consistently maintained. The turbine reaches its rated capacity of 1 MW at a current speed of 2.9 m/s. It has a rotor diameter of 16 m.
Unlike the Jindo turbine, the test system is mounted on to a monopile drilled into the seabed. The turbine rests under its own weight on the support structure and is installed and removed with the help of crane ships.