The average price of a solar panel has declined by 60% since the beginning of 2011

Solar power systems generate electricity at peak power usage times (during the day) when the value and cost of electricity is the highest. Modern grid-tied home solar power systems can use the cheap rate grid power at night and reduce or eliminate the need for the high rate electrical power during the day.  Home based solar power is a quiet, nearly maintenance free, continuous source of electricity.

http://solarenergy.com/