New solar arrays from SolFocus generate more power than conventional solar panels but use just one-thousandth as much expensive semiconductor material. The arrays' curved mirrors focus sunlight onto one-square-centimeter solar cells, concentrating the light 500 times and improving the cells' efficiency. SolFocus's first power-producing installation will be generating 500 kilowatts of electricity by the end of the summer. The company expects that by 2010, electricity from its arrays will be about as cheap as electricity from conventional sources.

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