The New Paper 11 Nov 08;
This week, Singapore hosted the International Energy Week where policy makers from all over the world met academics and industry players to talk about energy options and strategies for the future.
CHNG CHOON HIONG looks at tidal energy as it is used in the UK while TEH JEN LEE asks whether it could work here.
PICTURE a 37m-tall, 1,000-tonne windmill that is submerged under the sea and you get a good idea of what the SeaGen Tidal Energy generator is.11 November 2008
PICTURE a 37m-tall, 1,000-tonne windmill that is submerged under the sea and you get a good idea of what the SeaGen Tidal Energy generator is.
Situated in Strangford Narrows, off the coast of Northen Ireland, the SeaGen is the world's first commercial-scale tidal energy turbine, harnessing the virtually inexhaustible energy carried by tidal currents.
Tidal currents are caused by the gravitational interaction between the earth and the moon arising from their relative motion.
As such, the tidal cycle is perfectly predictable, an advantage over power generated by wind and sunlight.
There are, however, some drawbacks in harnessing tidal power.
It has some prerequisites which limit its use to just a few regions in the world.
There are also worries such as the possible disruption of marine life and the ecosystem. However, the concerns about damaging the ecosystem are yet to be firmly established.
Costing more than £8.5 million ($20 million) in development, the SeaGen is commissioned for operation till 2013. During this time, it will generate 1,200kW of clean renewable power, enough to provide for the electrical needs of 1,000 UK households.
Can this work in Singapore?
USING current technology, Singapore cannot harness tidal energy because our mean tidal range of about 1.7m is too low.
The New Paper 11 Nov 08
USING current technology, Singapore cannot harness tidal energy because our mean tidal range of about 1.7m is too low.
Mean tidal range is the difference in height between mean low water and mean high water levels during spring tides, which occur during new moon and full moon, when there is greatest variation in tides.
The tidal range is low all around South-east Asia because of the configuration of the land - fairly straight coastlines which are surrounded by seas.
In contrast, there are beaches in some countries elsewhere with a tidal range of more than 10m.
For example, in the Bay of Fundy on the Atlantic coast of North America, home to the world's highest tides, the tidal range has been measured in excess of 15m.
These high tides produce swift-flowing currents when the tide is coming in and going out.
In Singapore, because of the low tidal range, the tidal currents are not strong enough to generate electricity. It would be like trying to get power from water flowing through a monsoon drain.
Professor Teh Tiong Sa, visiting senior fellow at the Tropical Marine Science Institute, said: 'To have viable energy from tides, the higher the tidal range the better.
'For Singapore, it's too low to even think about it now, unless technology changes and things become more efficient.'