It may not be news that U.S. solar energy markets continued to boom last year. In fact, solar installations accounted for 31 percent of all electric power installations in 2013. It is always interesting, however, to look at public data for insight into why and how – what the trends and challenges are – the drivers of the growing solar markets. After collecting and analyzing available data for the seventh year, as author of IREC’s recently published U.S. Solar Market Trends 2013, the answer is quite clearly a combination of factors.