[en] The operating regime of tidal power plants requires ecological monitoring of their associated water area.

[en] Tide energy and oceanic current energy represent a strong potentiality for a few countries in the world including France. In the domain of tidal energy there are 2 strategies. The first one is based on the search for the lowest power production cost in order to contribute efficiently to the country's energy mix. Generally this strategy leads to the construction of tidal dams. The second strategy is based on the search for the lowest environmental impact. This strategy is economically competitive only in places where electrical power is expensive like isolated islands. This strategy is illustrated by the tidal power station of the Alderney island. In fact the amount of energy delivered by a tidal power station depends on the rise of the tide and on the surface of the dam. It appears that tidal dams require less surface that hydroelectric power plants. The energy of oceanic currents like Gulf Stream or the thermal energy of oceans or wave power are very little exploited now but represent a potentiality higher by several orders of magnitude than tidal energy. (A.C.)

[en] Further observations were made on the great potential for tidal power developments in NW Australia. Discussion on the Severn Barrage paper and environmental effects of tidal power plants centred mainly around the impact on bird populations. The topics covered were: the adaptability of birds to changes in their environment with particular reference to the importance of inter-tidal areas for wildfowl and wading birds in the United Kingdom; the creation of mudflats as replacement feeding areas for wading birds; whether there is a danger that pressure from the construction industry might result in a barrage being built before the uncertainties in the environmental impact assessment are removed. Separate abstracts have been prepared for the three papers under discussion. (UK)

[en] Emerging channel two year ago, the wave energies is today a booming sector with an appropriate technology. This document presents an economic analysis of this energy sector, the technology assessment, the projects in Europe and brings a special attention to the french activity in the domain. (A.L.B.)

[en] The world's first tidal power station is scheduled for stat-up in the spring of 2003. It is located in Kvalsundet, off Hammerfest, Norway. This is a pilot installation of a 300 kW tidal turbine at a depth of 50 metres. When fully developed in 2007, the tidal power plant will deliver 32 GWh per year. Hammerfest Stroem has patented the energy and the company hopes to be able to install similar power stations both in Norway and abroad. The potential worldwide is claimed to be more than 450 TWh per year

[en] The anticorrosion and halobios control is the key techniquesrelated to the safety and durability of tidal power generating units. The technique of material application, antifouling coating and cathodic protection are often adopted. The technical research, application, updating and development are carried on Jiangxia Tidal Power Station, which is based on the old Unit 1-Unit 5 operated for nearly 30 years, and the new Unit 6 operated in 2007. It is found that stainless steeland the antifouling coating used in Unit 1- Unit 5 are very effective, but cathodic protection is often likely to fail because of the limitation of structure and installation. Analyses and studies for anticorrosion and halobios control techniques of tidal power generating units according to theory, experience and actual effects have been done, which can be for reference to the tidal power station designers and builders.

[en] One describes a new approach to design tidal power stations free from certain drawbacks and boiling down to application of free ebb-tide flows in the water areas where the rates of the mentioned flows are the maximum ones. The implementation of the described idea may qualitatively change the structure of the power balance of Russia. Commissioning of the mentioned power stations does not require long terms and essential one-time investments and poses no ecological problems

[en] Together with wave energy, ocean thermal energy, and the often overlooked energy from ocean curents tidal energy belongs to those renewable energy sources that can be subsumed under the generic term of ocean energy. All that these energy sources have in common, however, is that they are found in the ocean. The present article discusses tidal energy with respect to the four principal factors determining the scope of a renewable energy source, namely global, technical, and economic availability and ecological acceptability. (orig.)

[en] Hammerfest was the first city in Norway with hydroelectric power production and the first city in Northern Europe to have electric street lights. Recently, technologists within the city's electricity supply industry have suggested that Hammerfest should pioneer the field of tidal energy. The idea is to create a new Norwegian large-scale industry. The technology is being developed by the company Hammerfest Stroem. A complete plant is planned to be installed in Kvalsundet. It will include turbine, generator, converters, transmission to land and delivery to the network. Once fully developed, in 2004, the plant will be sold. The company expects to install similar plants elsewhere in Norway and abroad. It is calculated that for a tidewater current of 2.5 m/s, the worldwide potential is about 450 TWh

[en] The challenge posed by climate change and the predicted scarcity of fossil fuels is so great that energy questions are increasingly in the headlines. There has, in this context, been an increasing promotion of renewable energies, as is attested by France and the EU's stated objective of producing 20% of consumed energy from renewable sources by 2020. Among the different renewable energies, the ocean represents an immense reserve (tidal and tidal-stream energy, wave and wind power, marine biomass etc.) and a genuine asset for those countries like France which have the good fortune to have many seaboards (both at home and overseas). In order to gauge the potential of marine renewable energies, Ifremer began an enormous foresight exercise in March 2007 examining scenarios to the year 2030 in partnership with the main actors in the maritime world and with methodological support from Futuribles. Denis Lacroix and Michel Paillard, who were members of the steering committee of that study, present the broad outlines of this foresight exercise and the possible prospects for marine renewable energies. After reviewing the various forms of marine energy, they set out the methods followed and the range of possible scenarios selected, together with the potential of the different technologies associated with marine renewable energies. They then show the extent to which these energies could contribute to the French energy supply to 2030, before developing a ''normative'' scenario that can serve as a strategic axis for French energy policy so far as marine renewable energies are concerned (on the basis of a contribution of around 3% to the French energy mix in 2020). (author)