Can we harness ocean energy
Thursday, 07 March 2013 00:00 - Last Updated Tuesday, 05 November 2013 17:48
Written by Glendon Glasgow
Information Officer - Institute of Marine Affairs
As seen in recent times, the ocean contains massive amounts of energy. Tropical storm Sandy
which devastated portions of the Caribbean and Northeastern United States during late October
2012 was able to harness just a fraction of the ocean’s energy to produce strong winds and a
massive storm surge, securing its place in history as one of the most unique storms recorded.
Many clean energy enthusiasts believe that the ocean as an energy source is often over looked.
Water covers approximately three quarters of the earth’s surface. The World Energy Council
estimates that the energy that can be harvested from the world’s ocean is twice the amount of
electricity that the world now produces. Trinidad and Tobago is still heavily dependent on
non-renewable resources such as oil and gas for the generation of electricity. The largest
percentage of electricity generated from oil and gas in Trinidad over the past 38 years was
99.81% in 2003, while the lowest value was 96.47% in 1971. Although the use of energy
generated by the ocean is increasing across the globe, Trinidad and Tobago and other islands
of the Caribbean have not as yet exploited this potential source of clean energy.
Renewable energy resources are the future as they are available in significant amounts and are
by far the cleanest sources of energy available on planet earth. These alternative sources of
energy generally require startup capital which is a challenge for many Caribbean islands. Tidal,
wave and ocean thermal energies are all within the realm of reality. The ocean can produce two
types of energy: thermal energy from the sun's heat, and mechanical energy from the tides,
waves and ocean currents. It is important that we understand some of the technologies that can
produce ocean energy and what it could mean for us in Trinidad and Tobago.
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Can we harness ocean energy
Thursday, 07 March 2013 00:00 - Last Updated Tuesday, 05 November 2013 17:48
Tidal energy is generated from the power of changing tides caused by the magnetic pull of the
moon. This may be achieved by building a dam across a bay or an estuary where there is a
significant difference between high and low tide. The high tides allow immense amounts of
water to rush into the bay. The gates of the dam then shut when the water level is at its
maximum height. When the tides fall the gates open and the water flows out and spins a turbine
which creates electrical energy. The world’s first Tidal Power Station, Rance opened on the 26 th November 1966 in France and
takes advantage of tidal water flow to produce electricity. A major drawback to tidal energy is
that it is not a constant source of electricity as it relies on the rise and fall of tides to work and
there are only two tides per day. For tidal energy to be considered economical a range of at
least seven metres at high tide is needed. Unfortunately in Trinidad waters, the highest tides
reach only two metres. So what does that mean for our future with tidal energy? Rather than
using a change in water height, offshore turbines are made to work just like wind turbines but
underwater, harnessing water currents to turn the turbines and produce electricity. These Tidal
Current technologies extract energy from the high tide bulge created by the gravitational pull of
the Moon and Sun moving horizontally around the Earth’s surface. Unless taken to extremes, it
does not require blocking of any waterways, and hence does not have the adverse
environmental effects associated with Tidal Barrages. Trinidad’s east coast is close to the
Guiana Current the second largest ocean current in the world, which has speeds between 0.2
and 4.2 knot that is sufficient to produce electricity using submarine turbines. Currently the
Institute of Marine Affairs (IMA) recognizes the potential for these ocean currents to power
submarine turbines and as such has embarked on a project that entails a detailed study of
ocean currents around Trinidad and Tobago especially in the Columbus Channel and the
Galleons Passage.
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Can we harness ocean energy
Thursday, 07 March 2013 00:00 - Last Updated Tuesday, 05 November 2013 17:48
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Can we harness ocean energy
Thursday, 07 March 2013 00:00 - Last Updated Tuesday, 05 November 2013 17:48
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This
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Trinidad
Express
Newspapers
on
Thursday
References
http://oceancurrents.rsmas.miami.edu/atlantic/img_mgsva/guiana http://powershift.anetce.com/tidal_dam1.gif
http://www.evwind.es/wp-uploads/2012/07/Pelamis-Wave-Energy-Converter
http://www.indexmundi.com/facts/trinidad-and-tobago/electricity-production
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