Gigaom: This year has turned out to be a boom year for the solar industry, thanks in no small part to lucrative government subsidies in Europe, particularly in countries such as Germany and Italy. New solar project installations shot up from 7.2 GW in 2009 to an estimated 15.8 GW in 2010, according to iSuppli. But analysts are predicting slower growth in 2011 because incentives in these key European markets are set to fall quite a bit. At the same time the U.S. market could grow faster. Here are key trends I expect to see in 2011.