Inventions and Inventors Volume 1 - Online Public Access Catalog

Electric Power from Tides
Tidal power plant / 771
Modern society requires tremendous amounts of electric energy
generated by large power stations. This need was first met by
using coal and by damming rivers. Later, oil and nuclear power became
important. Although small mechanical tidal mills are inadequate
for modern needs, tidal power itself remains an attractive
source of energy. Periodic alarms about coal or oil supplies and
concern about the negative effects on the environment of using
coal, oil, or nuclear energy continue to stimulate efforts to develop
renewable energy sources with fewer negative effects. Every crisis—for
example, the perceived European coal shortages in the
early 1900’s, oil shortages in the 1920’s and 1970’s, and growing
anxiety about nuclear power—revives interest in tidal power.
In 1912, a tidal power plant was proposed at Busum, Germany.
The English, in 1918 and more recently, promoted elaborate schemes
for the Severn Estuary. In 1928, the French planned a plant at Aber-
Wrach in Brittany. In 1935, under the leadership of Franklin Delano
Roosevelt, the United States began construction of a tidal power
plant at Passamaquoddy, Maine. These plants, however, were never
built. All of them had to be located at sites where tides were extremely
high, and such sites are often far from power users. So
much electricity was lost in transmission that profitable quantities
of power could not be sent where they were needed. Also, large
tidal power stations were too expensive to compete with existing
steam plants and river dams. In addition, turbines and generators
capable of using the large volumes of slow-moving tidal water that
reversed flow had not been invented. Finally, large tidal plants inevitably
hampered navigation, fisheries, recreation, and other uses
of the sea and shore.
French engineers, especially Robert Gibrat, the father of the La
Rance project, have made the most progress in solving the problems
of tidal power plants. France, a highly industrialized country, is
short of coal and petroleum, which has brought about an intense
search by the French for alternative energy supplies.
La Rance, which was completed in December, 1967, is the first
full-scale tidal electric power plant in the world. The Chinese, however,
have built more than a hundred small tidal electric stations