According to a report by the Solar Energy Industries Association (SEIA), the U.S. market for rooftop PV increased 41% in in 2013 over its 2012 level—nearly fifteen times the amount installed in 2008. California continues to lead the U.S. market and installed more than half of all U.S. solar in 2013. In fact, the state installed more solar last year than the entire United States did in 2011. The top five states—California, Arizona, North Carolina, Massachusetts, and New Jersey—accounted for 81% of all U.S. PV installations in 2013.

As demand for rooftop solar has increased, the cost to install PV panels fell throughout 2013, ending the year 15% below the mark set at the end of 2012. Read more.