The U.S. greentech sector saw 353 transactions completed in 2011 for a reported $13.9 billion—down 6% from the $14.7 billion posted in 2010. While greentech funding rose 4% to $10.6 billion, mergers and acquisitions slumped 29% to $3.3 billion. Some of the major developments (or lack thereof) included the rollout of electric vehicles from Chevrolet and Nissan, the shocking demise of thin-film solar manufacturer Solyndra, and another year of stalled progress in the area of U.S. energy policy. To learn more about how greentech M&A fared in 2011, make your way over to our 2011 Greentech M&A Review.