Building turbines on land can be just as controversial, suitable locations for fixed-base shallow-water turbines are limited and a new generation of big turbines will need lots of space: only a couple can be placed in each square kilometre.

ECONOMIST: Monitor

The moldy walls and water-damaged ceilings in one building on base have already been repaired.

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The firm, partly funded by Statoil, Norway's energy giant, estimates that each will cost about as much as a fixed-base turbine placed in 30 or 40 metres of water.

ECONOMIST: Monitor

However, the installed base of solar thermal electricity generation uses twice the water as coal and five times the amount as gas-fired plants.

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