7 ноя 2010 г. - solar energy

Описание:

In many countries, the number of homes with solar power was growing exponentially during 2010, thanks to plummeting costs and new government incentives. This was particularly true in the USA, where the cost of a typical five-kilowatt rooftop system fell from $22,000 in 2007 to just $13,000 by late 2010. This technology would soon become affordable to the middle classes.

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