Heat from the sun boils water to run a steam turbine generator, which delivers power to the grid.

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To supply the extra juice, utilities turn on inefficient single-cycle gas turbines, which turn 25% of the fuel's energy into electricity, as opposed to 45% for combined-cycle plants that use turbine exhaust to make steam to run a second generator.

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Ivanpah is a solar concentrator project, using fields of mirrors, known as heliostats, to concentrate sunlight onto a solar receiver on top of a tower. (This project when finished will include 173, 000 heliostats.) The concentrated sunlight is used to heat water, generating steam which is used to turn a traditional turbine and generator to produce electricity.

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