Alstom enters the Ocean Energy market, reinforcing its renewable energy portfolio
Clean Current tidal turbine technology
Various types of Ocean energies The oceans contain a tremendous amount of energy and are close to many - if not most - concentrated populations. Many researches show that ocean energy has the potential of providing for a substantial amount of renewable energy around the world. Oceans represent a vast and largely untapped source of energy, in the form of fluid motion (currents, waves, and tides--also termed hydrokinetics) and thermal and salinity gradients. There are a number of approaches to extracting energy from the ocean, though most remain in the investigation or demonstration phase: - Tidal Range Power exploits the difference in height of the tides, such as in the La Rance Power Plant, in France - Tidal Stream Power exploits the velocity of the tidal currents - Ocean Current Power exploits the velocity of the permanent ocean currents - Wave power exploits the motion of the waves - Ocean Thermal Energy Conversion exploits the difference between sea surface temperature and sea bottom temperature - Salinity Gradient Power exploits the different of salinity between fresh water and sea water in estuaries
Conditions required to install Tidal Stream Turbine Technology Tidal Stream Turbine Technology can be installed at places with high tidal current velocities (typically faster than 3 m/s) to extract energy from these huge volumes of flowing water. These flows have the major advantage of being an energy resource which is as predictable as the tides that cause them, unlike wind or wave energy which respond to the more random quirks of the weather system. Tidal Stream Turbines are usually installed in 30 to 60 m deep sea. Additional characteristics that make for a favourable tidal stream site are the flatness of the sea bed, proximity to the shore, the proximity to a robust power network, and the availability of good port and assembly facilities at a reasonable distance.
Tidal Stream Turbine Technology Tidal Stream energy refers to extracting electrical energy from currents of water generated by the gravitational pulls of the moon and the sun. The Clean Current turbine is governed by the same principles that apply to traditional wind turbines except that water is more than 800 times denser than air. Therefore, a 5 knot (2.5 m/s) tidal current contains more power per m2 than an 80 km/h wind. The water stream energy is converted to rotational mechanical energy through a bi-directional turbine. The turbine rotor assembly consists of 5 rotor blades with permanent magnets attached to the inner rim adjacent to the central hole ( see Figure 1). Rotational energy is then converted to electrical energy by Clean Current's proprietary direct drive, variable speed, fault-tolerant permanent magnet generator. The output electricity is then brought to shore in a sub-sea cable, rectified and inverted to produce electricity that can be delivered to customers. The turbine has only one moving part, the rotor assembly, providing unprecedented reliability. There is no gearbox. The Clean Current turbine is designed to minimise maintenance requirements, and to maximise reliability and lifetime. During its lifetime, it will generate electricity with zero greenhouse gas emissions, a modest footprint on the bottom of the ocean and negligible impact on marine life.
Bi-directionality and Efficiency The Clean Current turbine has been designed to extract power from both ebb and flood tides with equal conversion efficiencies. This is achieved through the use of symmetric blades, stay vanes and augmenter sections. Figure 1 above shows this symmetry. This view also illustrates the central hole that serves as both a bypass for fish and marine mammals as well as a method of increasing the overall performance of the turbine. The augmenter duct and hole design together increase efficiency by correcting directional changes, controlling turbulence and increasing the velocity of the water reaching the blades.
About Alstom Alstom is a global leader in the world of power generation and rail infrastructure and sets the benchmark for innovative and environmentally friendly technologies. Alstom builds the fastest train and the highest capacity automated metro in the world, and provides turnkey integrated power plant solutions and associated services for a wide variety of energy sources, including hydro, nuclear, gas, coal and wind. The Group employs 81,500 people in 70 countries, and had orders of €24,6 billion in 2008/09.
About Alstom Hydro * Alstom Hydro, has over 400 GW of turbines and generators installed worldwide which represent more than 25% of the total global hydropower installed capacity. As the world leader in the supply of hydropower equipment & services, Alstom Hydro offers products and turnkey solutions that cover all hydropower schemes, from large to small, from run-of-river to pumped-storage. With more than 6000 employees in 19 countries Alstom Hydro offers the broadest range of products and services for new installations, refurbishment, upgrading and services.
About Clean Current **Clean Current Power Systems Incorporated is a private Canadian company based in British Columbia that develops, designs and tests proprietary tidal energy technology that converts the kinetic energy of tidal currents into electricity.
Press Contacts philippe.kasse@chq.alstom.com, stephane.farhi@chq.alstom.com Susanne Shields (Press Relations Officer) – Tel +33 1 41 49 27 22
Investor Relations
Websites:
Contact Glen Darou, President and CEO Clean Current Power Systems Incorporated Email: glen.darou@cleancurrent.com Web: www.cleancurrent.com
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