Scrubbers used in thermal power plants, for instance, require limestone to capture sulphur from their exhaust.

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BrightSource was founded in 2004 by American-Israeli pioneer Arnold Goldman, whose Luz International built nine solar thermal power plants in the Mojave Desert in the 1980s and 1990s.

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But without Belo Monte, Brazil would probably have to build nuclear power plants or invest in coal-fired thermal energy.

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This was after the leak at the Fukushima nuclear plant resulted in other nuclear plants being shut, forcing it to rely on traditional thermal power stations to produce electricity.

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Apart from nuclear power plants, the Japanese utility has shut down thermal plants in the Tohoku and Kanto areas, also afflicted by the intensity of the massive 9.0-magnitude earthquake and ensuing tsunami.

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The earthquake and tsunami last year resulted in 15 of its 17 nuclear plants being closed, forcing Tepco to turn to thermal stations for power generation.

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It is developing giant off-shore wind turbines, biomass power plants (including projects in Florida and Washington with Duke Energy), and, with its Ausra acquisition, solar thermal power plants.

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However, since Brazil switched on more gas-fired thermal plants in October, to cope with growing demand and ease the pressure on the hydroelectric power system, costs have increased significantly.

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