|
TIDAL ENERGY
One of the newer forms of sustainable energy is tidal
energy, a form of hydroelectric power. Like other
renewable sources, it was first used to grind grain in
small-scale operations, and is now used to turn turbines
to generate electricity. The first commercially viable
tidal power plant was in France in1966, and it has seen
continuous growth since then as technology improves.
Though they are similar to windmills, tidal generators
offer some significant advantages over their land based
counter parts. First, tides are more steady than the
wind; they are predictable, occurring twice a day every
day, everywhere in the world. Second, they offer greater
potential energy production because water is denser than
air, and thus can generate far more turbine power than
air. Third, tides occur in every ocean of the world, and
are available on far wider geographic scale than wind
power.
UK based?
Check here for information about
how to save money on car insurance
There are basically three types of tidal generators.
Barrages are dam-like structures that are built across
an entire bay or inlet; the changing tides force water
over the barrage and onto the turbines. Of course, the
environmental impact of these structures is
considerable. They often cause damage similar to that of
conventional dams, such as stagnation, plant
decomposition, and destruction of fish populations.
Additionally, there is a lack of viable sites in the
world.
A second tidal generator uses the tides to directly turn
the turbines, just as a windmill used the wind. These
are much simpler to construct, and cause far less
environmental damage. They look very similar to
windmills and can be built with much less surface area
than barrages.
The newest technology is known as dynamic tidal power. A
long dam is built perpendicular to the shore, straight
out into the ocean. This causes a disparity in water
level on either side of the dam, and the changing tides
can again force water over a turbine. The primary
disadvantage of dynamic generation is that it requires a
substantial structure (usually a minimum of thirty
kilometers long) to be economically viable, and be
strong enough to withstand severe ocean weather. The
long-term ecological impact of such a massive structure
is still under investigation.
Published by Carol Foss - in the hope that it will make
a difference, however small. |
