The SEIA/GTM U.S. Solar Market Insight Report is a regularly cited source each quarter by over 200 top national media, regional news outlets, solar trade press, bloggers and U.S. government agencies. Photovoltaic (PV) installations continued to proliferate, increasing 41% over 2012 to reach 4,751 MW. Solar was the second-largest source of new electricity generating capacity in the U.S., exceeded only by natural gas. And the cost to install solar fell throughout the year, with average system prices ending the year 15% below the mark set at the end of 2012.