Tidal Power: Array Wave of the Future?

Tidal power is using the tides to extract energyThere is hope that this would be used specifically
to convert into electricity. The tides are the resultin remote areas such as the Highlands and Islands
of the gravitational force between the Earth andof Scotland.
Moon. On a daily basis this force pulls up tons ofWorld wide only about 20 sites have been
water, thus the tides. The tides are also broughtidentified as having the potential to harness the
back down, allowing for tidal power to be usedpower from the waves. This is due to the fact
twice daily, which would sum to about 10 hours.that between 12 and 18 feet difference (called
Tidal power is catching this water when it is at'head') between high and low tide is needed, and
high tide and storing it in reservoir type structuresvery few areas experience this range of heights.
until the time of low tide. During low tide, the(In the United States one of the only usable sites
water is released, allowing it to flow back out tois at Nantucket, though it is unlikely that they will
sea through the turbines, and thus generatingbegin construction due to the unpleasing
power. In order to create a tidal plant, we build aappearance of the plants)
dam, called a barrage, at the bottom of a tidalAnother option yet to be completely explored
basin. This includes a device called a sluice, whichwould be to use offshore turbines
opens up allowing the tide to come in at high tide.(Somewhat comparable to an underwater wind
This water rushes past a turbine that is attachedfarm.) These would be quite a lot cheaper than
to a generator, or in some cases the waterbuilding the large-scale bridges and wouldn't pose
pushes air through tunnels that then act like windsuch risks to the environment. There are many
through a turbine. When it is time for the tide tomore potential sites for this type of technology
go out at low tide, the function of the sluicethan the current tidal technologies. Some would
reverses and the water flows back out throughspeculate that these would pose risk to marine
the turbines.life, but it has been pointed out that they pose far
Historyless risk than the propellers on ships, as they are
Utilizing the tides was first done in the 18thboth stationary and rotate 10 times more slowly.
century to compete with windmills and anotherAdvantages and Disadvantages:
water technology--water wheels. Water mills wereOnce constructed, it is a free source.
quite popular but became scarce once the steamNo greenhouse or other gas emissions.
engine gained its popularity. Tidal power plantsReliable.
have not traditionally been a popular way toInexpensive to maintain.
convert energy into electricity.Tides are very predictable.
Current UsageNeeds to be close to the coast.
Presently France is the only country thatNot a continual energy supply throughout the day.
successfully uses the tides as a power source. InNot aesthetically pleasing.
their country, tidal power accounts for just aboutTidal power has the potential to one-day account
240 megawatts of power at the world's largestfor one fiftieth of our total power consumption,
tidal plant--the La Rance. This facility wasso they could never solve our current energy
constructed in 1966, and is currently Europe's onlydilemma. They could provide assistance, but never
tidal plant. This plant provides roughly enoughmore than that--we could not totally rely on this
energy to fuel 240,000 homes. Though thetechnology. The greatest drawback is that we
energy source is both reliable and plentiful,know little about the effect this has on marine life.
extracting usable power from it is not.There is always a potential threat to the natural
Futureecosystems when we disrupt nature's processes,
The comparison between tidal energy now andand the ocean is no exception. The reduced tidal
wind energy 10 years ago has been made.flow that Tidal energy systems cause has
Researchers are hopeful that developments toenvironmental impacts on tidal basins because
the technology can be made. One offshoot ofthey decrease the flow of the tides and also silt
tidal power that is currently being researched isbuildup. There is speculation that if we use this
the possibility of using the energy extracted fromtechnology to a great degree the tides will slow
waves to produce hydrogen for fuel or fuel cells.down, posing a great treats to the ecosystem.