Solar power significantly increasing in residential installations

Solar power In the U.S. is presently a minor contributor of electricity, but it is significantly increasing in residential installations.  The Solar Energy Industry Association (SEIA) estimates that the residential photovoltaic market in the U.S. doubled in 2009. The price of PV modules (which account for up to half of the cost of an installed solar system) fell by more than 40%, to between $1.85 and $2.25 per watt. A typical residential system for new homes can produce between 3.5 and 7 kilowatts at any given time.  SEIA also estimates that average installed costs fell by about 10% in 2009.