Battered by soaring energy costs and aghast at dwindling fish stocks, Japanese scientists think they have found the answer: filling the seas with giant “eco-rigs” as powerful as nuclear power stations.

The project, which could result in village-sized platforms peppering the Japanese coastline within a decade, reflects a growing panic in the country over how it will meet its future resource needs.

The floating eco-rig generators which measure 1.2 miles by 0.5 miles (2km by 800m) are intended to harness the energy of the Sun and wind. They are each expected to produce about 300 megawatt hours of power.

Some energy would be lost moving the electricity back onshore, but when three units are strapped together, scientists at Kyushu University say, the effect will be the same as a standard nuclear power station.

The eco-rigs' gift to the environment does not stop there: some of the power that the solar cells and wind turbines produce will be hived off to fuel colossal underwater banks of light-emitting diodes (LEDs).

The lamps are intended to convert the platforms into nurseries for specially selected seaweed that absorbs carbon dioxide and feeds fish and plankton. Deep-sea water that is rich in minerals will enhance the seaweed growth. The wind turbines will power pumps that will then draw the water to the surface.The rigs will be unmanned and comprise several hexagonal platforms.

Strapped between them will be large nets designed to support the weight of wind turbines and about 200,000 hexagonal photovoltaic generators — super-efficient solar panels that are about the size of a double bed. The LEDs will shine down from the panels.

As a country with virtually no fossil fuels, price rises in oil and gas have chilled the corporate sector and the Japanese Government.

Japan's faith in nuclear power has also taken a beating. An earthquake caused its largest nuclear plant to shut down in 2007 and engineers and seismic experts cautioned that the country's high susceptibility to quakes placed the industry at risk.

The Kyushu team says the plans are about three years away from becoming reality. It began tests on a scale version of the eco-rig last month, and full-scale official evaluation is expected to begin soon.

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