Coal-fired floating power plants proposed off Japan

The development of coal- fired power stations that would float off the Pacific coast is being considered as an answer to some of Japan's most pressing problems.

First, these stations could help the government achieve its plan to wean the country off oil and on to coal as a major power source.

Second, they would overcome the acute shortage of land for power stations, while making better use of the surrounding ocean areas, one the few spaces Japan has in abundance.

The idea of "floating coal energy centers" is being examined by the Ocean Development Council of the Federation of Economic Organizations (Keidanren -- an organization involving top business leaders which has enormous influence on the government). It is supposed to present a detailed plan to the Transport Ministry by spring.

According to the ministry officials, the present proposal outlines a semicircular breakwater to be built in the ocean 30 or 40 kilometers from the coast.

A floating power plant would then be constructed within this breakwater. Japanese shipbuilders have considerable experience with such structures, as they built a combined floating pulp factory and power plant for installation on the Brazilian plantation of American billionaire Daniel Ludwig in the late 1970s.

Sites of comparatively shallow water depth -- 20 to 50 meters -- would be sought. There are several sites along the Pacific coast that qualify, with the additional benefit of close proximity to the two major urban-industrial conglomerations of Tokyo and Osaka.

Each floating center would have a pier capable of handling coal freighters of up to 10,000 deadweight tons.

In the government's longterm energy plan to promote use of thermal coal, environmental considerations such as waste disposal have been among the most bothersome questions. Ministry officials say that for every 100 tons of coal burned in a power station, 20 tons of cinders are produced.

The floating power stations, however, have no such problem -- "The cinders will simple be dumped over the side," one informed source said. The idea as that the ash will be sunk inside the breakwater until an artificial island has been created.

Proponents of the plan envisage the eventual emergence of the whole string of such man-made islands off the coast. If they are placed carefully, it should be possible to create a calm "inland sea" conducive to extensive fish cultivation, they claim.

Fish cultivation -- which is now being developed in Japan's naturally created "inland sea" stretching from Osaka to the southern island of Kyushu -- has become necessary since 200-mile offshore economic zones have made it difficult to supply enough fish to meet Japanese dietary demands.

It is unlikely the first floating power station will emerge much before the end of the decade. As a first step, the Transport Ministry will probably spend the next three years building a model about one-tenth the size of the proposed full-scale plan to investigate the technical problems involved.

There are bound to be questions of possible environmental damage to fishing areas, officials admit. Also, the ocean areas involved are prone to extremely violent typhoons at certain times of the year, making the safety of the proposed structure an important consideration. In addition, there is the question of how to connect the electricity output to the major urban centers.

Experts believe the building of one such floating power station, including its conversion to a man-made island, would be at least $3.5 billion.

But proponents of the idea believe the cost is justified by the better utilization of surrounding ocean and the freeing of land that could be used for the government's ambitious alternative energy program for residential and industrial purposes.

One hurdle to be overcome is the total indifference that the electric power industry has so far displayed. The Transport Ministry is hoping that Keidanren and the Ministry of International Trade and Industry will somehow be able to whip up the necessary enthusiasm.