Ocean Current Technologies

Transcription

1 Ocean Current Technologies

2 1 Tidal power At Voith Hydro Ocean Current Technologies The power of water presents great potential for clean, renewable energy generation. Water covers 71% of the earth s surface, and the World Energy Council estimates that the harvestable energy from the world s oceans is equal to twice the amount of electricity produced in the world today. Voith Hydro Ocean Current Technologies (VHOCT) is an innovative company developing a technology that harvests tidal current energy. VHOCT was founded as a joint venture in 2009 by Voith Hydro, with an 80% share, and Innogy Renewables Technology Fund, with 20% share. Our vision The rising demand for energy and the need for reducing emissions will encourage the implementation of new forms of renewable energy. Ocean Energies primary wave and tidal fulfill the requirement of providing new renewable energy at reasonable cost. Voith Hydro with its expertise in traditional hydro power, its R&D excellence and its value-oriented customer solutions, is a strong player in the development of this industry. 2

3 MW turbine during installation 2 Turbine in Nacelle Retrieval Module prior to installation 3 Tidal current turbine (110 kw) Harnessing The power of ocean currents The design approach Estimates indicate that power from tidal currents could add approximately 100 GW to the world s electricity supply. Voith Hydro has developed a comprehensive solution for harvesting this energy, centering around a horizontalaxis turbine and including a simple deployment and retrieval system. The design addresses technology reliability, which is a key factor in the industry s advancement, considering the harsh marine environments to which turbines are subjected. In addition, its oil-free seawater lubrication system ensures environmentally friendly and low-maintenance operation. Technology overview Voith Hydro s solution for tidal current energy utilization is a robust horizontalaxis turbine with a three-bladed rotor and a customized deployment apparatus to provide for reliable access to the system. The turbine can be mounted on any type of foundation, including monopiles, gravity-based foundations, floating structures, or bridge attachements. The rotor diameter can be adjusted to ensure optimal energy extraction, according to site-specific conditions and water depth. 3

4 Encapsulated generator (electrical parts statically sealed) Bearings (sea water lubricated) Rotor Connection to tower Schematic representation of turbine technology The 1MW commercial scale turbine installed on a drilled monopile which represents one of several possible foundation types A tidal turbine must operate and produce power reliably in one of the harshest conditions on earth. This incredible challenge requires a low-maintenance solution that minimizes the e xpensive offshore operations involved in maintenance and repair work. Therefore VHOCT s driving is to keep complex systems and components out of the turbine and to focus on simple, robust and reliable technology. The bearings need no sealing against the external medium of sea water. Instead they use the sea water itself to create a lubricating hydrodynamic film. Thus both complex measures for sealing and peripheries such as leakage water pumps are avoided. The machine is protected from corrosion and marine fouling by proven coatings and sacrificial anodes. Advantages of our turbine Robustness through minimization of failure-prone and maintenance-intensive parts: Direct drive, gearbox-free coupling Permanent magnet excitation Variable speed to accommodate fixed-pitch blades Symmetric blade profile for bidirectional operation avoiding pitch and yaw requirements Elimination of grease through seawater ubrication technology Elimination of dynamic seals 4

5 Acoustic Doppler Current Profilers are used to measure the speed of the tidal stream at site Resource Assessment In power plant design, it is of highest importance to match the power conversion technology to the energy transport medium. In tidal currents, the harvestable energy is the kinetic energy of the tidal flow. Hence a comprehensive and accurate description of the tidal currents is paramount for the determination of annual electricity production potential, as well as for extreme and fatigue loading design for the power plant s estimated 20-year lifetime. The environment in which the turbine operates is impacted not only by constellations of the earth, sun, and moon s gravitational forces, but also by meteorological phenomena. The celestial influences can be described by collecting and analyzing long-term measurement data to define the tidal constituents that correspond to cyclical movement of the heavenly bodies. Of equal importance for design is the description of met-ocean conditions, such as wind and waves, which can occur at the installation location. For this, weather station data and longterm wave buoy measurements are used to inform numerical simulations. Extreme care must be taken during these endeavors in order to ensure reliable operation and economic viability over the lifetime of the project. 5

6 t3365e Voith Hydro Holding GmbH & Co. KG Alexanderstrasse Heidenheim, Germany Tel Fax A Voith and Siemens Company