WATER POWER
The Force That Flows Water
power, used for centuries to turn mechanical waterwheels, can now
be harnessed to generate electricity and heat. Water is constantly
moving, flowing downhill from land to sea, where it is swept by
tides, washed upon coastlines, and channeled into vast oceanic currents.
In 1882, the world's first hydroelectric dam began producing electricity,
and by 1975, water power yielded one quarter of the world's electric
power. Around the world, water power exists at thousands of potential
new dam sites ranging from streams to large rivers. Likewise, existing
dams wirthout turbines and generators carry an enormous possible
capacity to make electricity and although many small dams that once
produced power have closed, there is a growing trend to reopen such
plants, as in Massachusetts and New York.
Tidal power, another form of water power, was first used hundreds
of years ago in England to mill grain. In 1966, the French built
the first commercial facility on the Rance River in northern France.
Rising and falling waters there spin turbines to generate 240 million
watts of electricity. Potential tidal sites have been identified
along the shore of 23 countries so far.
New forms of unutilized oceanic water power are being explored
. For example, floating ocean thermal energy conversion (OTEC) plants
can generate electricity by utilizing the temperature difference
between sun-warmed surface waters and colder deep waters. A samll
OTEC plant pilot plant is operating in Hawaii and there are no technical
barriers to building large OTEC plants. Also, further research and
development will enable countries ike Japan and Ireland to capture
the force of rising and falling waves along their coastlines. Creative
engineering is turning up other sources of water power. For instance,
some American towns have installed hydroelectric generators flowing
through city water mains, as in Philipsburg, Montana.
Together, these new and old technologies will maintain and increase
water power's role as an unending source of renewable energy.