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Retrospect

Difficult to tame

Since the 18th century, people have been trying to generate energy from the sea

The attempts to make energy from the sea by using the movement of the waves or of the tides are not a mere reflection of the tireless search for cheap and nonpolluting sources, intensified in the last 35 years.

The idea is centuries old and has been registered in documents, drawings and photos in several countries of the world. Two Frenchmen from the 18th century – Phillip Girard and his son, whose first name was lost – registered the first patent that one knows of an engine moved by waves. The French text is dated July 12, 1799, but it is not known whether the two Girards tried to put their own invention into practice. This, incidentally, is the rule for the patents of machines thought up to work as maritime power plants. Between 1855 and 1973, the English totted up 340 in Great Britain alone on the same subject. In the United States, there have also been numerous patent registrations, a good deal of them back in the 19th century. There, it is possible to find collections of photos with the various experiments of dilettante inventors. The one that illustrates this page is of an engine built in 1891 by Henry P. Holland, installed on a large rock on the beach of San Francisco, California. The waves moved a large float, which activated a pump, to make the water from the sea pass through mechanisms that ought to generate electricity. It was probably the first engine built  in that region with a commercial proposition, but it did not work as planned, and the project was abandoned in the following years. The structure remained spiked into the rock for 59 years, before being definitively destroyed by a storm.

“The first power plant really to work was installed in the port of Huntingdon, also in California, in 1909”, says engineer Eliab Ricarte Beserra, from the Submarine Technology Laboratory of the Graduate Engineering Project Coordination (Coppe) of the University of Rio de Janeiro (Coppe/UFRJ). This machinery also ended up destroyed by the force of the sea. After the intense activity at the end of the 19th century and beginning of the 20th, the problem was only taken up again forcefully during the oil crisis of the 1970s. “It was in this period that British engineer Stephen Salter, from the University of Edinburgh, Scotland, ascribed to the academic world the responsibility for designing an effective, long-lasting and commercially viable wave power station.” Thanks, in good measure to Salter’s successful experiments, around 20 countries are investing today in wave power stations, although only Scotland, Portugal and Holland have commercial models in operation. In Brazil, a pilot power plant will begin to work before the end of this year, in Ceará, under the charge of researchers from UFRJ.

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