(Boulder, CO – September 14, 2010) – With 648 community solar tours registered to date, momentum is building to make the 2010 American Solar Energy Society National Solar Tour the most successful grassroots solar event in history, engaging tens of thousands of solar-interested citizens across 48 states.  The 648 tours featured in this year’s National Solar Tour is nearly triple the number of tours featured in 2009, and more communities continue to join the movement each week.  Last year, 150,000 people across 49 U.S. states, Washington, D.C. and Puerto Rico participated.