A change in the tide for power generation

Brussels, 07 Oct 2003

Norway is the first country to produce a commercial solution to a major engineering challenge: how to tap the latent energy in tidal currents, according to a recent New Scientist report.

Our seas rise and fall like clockwork because of the effects of the sun and the moon on the Earth. As such a predictable and constant source of potential energy, authorities - including policy-shapers at the European Commission - have long sought a commercially and scientifically viable model to generate electricity from the tides.

The Norwegians have shown it is possible. On 20 September, representatives from Hammerfest Ström, the company behind the project, switched on the sub-sea power plant which, reports say, could be generating enough electricity for hundreds of thousands of homes in Norway within five years. But there is still some heavy research and engineering work to be done before this form of power generation becomes cost-effective.

Although still a demonstration version, this is the first commercial generator in the world to connect tidal power to the electricity grid. Bjorn Bekken, project manager at Hammersfest Ström, says the prototype should provide valuable data for building further sub-marine power stations in the coming years. "I hope to see underwater energy farms within five years," he is quoted as saying. The company envisages installing up to 20 tidal mills off the coast of Hammerfest.

Experts in Europe see the Norwegian achievements as a positive step in the battle to meet the world's Kyoto protocol commitments - to reduce the level of harmful gas emissions in the atmosphere. Despite costing more than wind-generated electricity at the moment, tidal power holds enormous potential alongside other renewable energy forms, such the sun, hydrogen power and nuclear fusion.

How it all works

The underwater device harnesses the sea's tidal movement much the same way a windmill generates power from air currents - huge blades resembling an aircraft propeller rotate as water passes around them, converting kinetic energy from the currents into electricity. Each propeller is coupled to a generator from which the electricity produced is sent, via a shore-connecting cable, to a transformer and then delivered to the grid.

Community interest in such renewable energy as tidal power has been building momentum since the announcement of the European Parliament and Council's directive ( 2001/77/EC ) on the promotion of electricity produced from renewable energy sources in the internal electricity market.

"The potential for the exploitation of renewable energy sources is underused in the Community at present. The Community recognises the need to promote renewable energy sources as a priority measure given that their exploitation contributes to environmental protection and sustainable development," states the directive.

This directive has been fleshed out in various Commission programmes, including applications in the Research DG's Sixth Framework Programme for research in the 'sustainable development, global change and ecosystems' thematic area. The Commission has also conducted studies to identify sites for tidal power generators. It concludes that there over 100 potential sites around Europe, some 40 of which are off the coast of the UK alone.

DG Research
http:///europa.eu.int/comm/dgs/research/i ndex_en.html
Item source: http:///europa.eu.int/comm/research/headl ines/index_en.cfm