Electrical
Power Produced By Means of Tidal Generators and Its Consequences as They Relate
to the World in Which We Live
By: Joshua Smith
February 14, 2002
Of late, humankind has come to the
realization that the world is, in fact, quite fragile. As time progressed, technology advanced and
we began to exploit our environment.
With the industrialization of the world came the corruption of nature:
in our attempt to take full advantage of the planet we began unknowingly
destroying it. Ignorant of the
consequences of our exploitation, we continued ravaging the planet for
resources. The atrocities committed
against the planet are seemingly irreversible.
Unfortunately, it took the passing of the point of no return to realize
we had even reached it. Now, we hope
that by developing cleaner systems and managing resources more intelligently we
can make right our wrongs.
Since the industrial revolution,
electricity has become a necessity for any technologically advanced nation to
thrive. At the time of the
proliferation of electricity, the world was not environmentally conscious and
took advantage of the process of coal-produced electricity. Over time other methods were developed but there
were none that were totally safe to the planet. Near the end of the Twentieth Century, the intelligentsia of our
race saw the effects of “dirty” electricity began attempting to develop a “clean”
means of production. One such means
involved harnessing the power of the oceans’ tides and is the subject of this
analysis.
Tidal energy production is simple,
theoretically. The tides obviously
contain a large amount of energy and we can make use of this natural phenomenon
with tidal power stations. Tidal power generators could be placed over a delta,
an estuary, a beach or any other places that experiences the tides. First, a
dam (or barrage) is set across a beach or river. When high tide comes in, water
flows through a turbine to create electricity. A portion of the water passes up
and over the barrage. A gate is lowered and said water is trapped behind the
barrage. When low tide comes, the gate is raised and the water flows out, passing
through the turbines and producing more electricity. Coupled with this two-way
turbine, some tidal power stations (such as the one on the Rance River in
France) can produce 320 megawatts of electricity.
Superficially, tidal electricity generation
seems flawless. Utilizing a natural process
of the earth in order to garner a needed commodity appears quite acceptable. It is conceivable that whole coasts could be
lined with tidal generators and could power the world efficiently and without
damaging the environment. This is not
so, as at least a four meter difference in tides is needed to effectively
produce. In addition to the necessary
setting, there is a huge economical hurdle to be cleared: tidal power stations
are very expensive. More important than
the financial concern is the environmental impact of tidal power generators.
Marine and estuarine life forms will
be greatly affected by the implementation of a tidal power station. It is estimated that in the Bay of Fundy, one
of the most promising sites for a tidal power station with a mean tide
difference of 15 meters, the installation of a generator could potentially stimulate
growth of “red tide” bacteria. This
bacteria is known to cause paralysis in shellfish. At any given site a tidal power station would alter the migration
routes and the composition of food sources for aquatic organisms.
Tidal power stations may not produce gases
that contribute to acid rain and global warming (like the burning of fossil
fuels), and they may not produce harmful radiation (like nuclear power plants);
but they would have a negative effect on the already damaged oceanic environment. Simply put, tidal power is not
environmentally feasible. The
opportunities presented by solar and wind electricity production are much more promising. While they may not yet be able to generate
as much energy as tidal power stations, they are at least earth-friendly and at
this time, that is by far more important.
http://bigbro.biophys.cornell.edu/~duesing/work/ba.html
http://hydroelectricity.hypermart.net/tidal.html
http://www.iclei.org/efacts/tidal.htm
http://www.fisheries.org/resource/page15.htm
http://atschool.eduweb.co.uk/dcastle/tidal.html