http://www.darden.virginia.edu/web/uploadedFiles/Dard en/Batten_Institute/Publications/Greentech_041212_Em ail.pdf

A recent Batton Institute Briefing on “Winning the Green Innovation Economy: A Guide to Worldwide Patenting” gives a breakdown of patenting activity by country, region, and technologies. The three leading countries, by number of greentech patents issued since 1990, are the US (67,432), Japan (53,217) and Germany (36,328). The strongest growth for greentech patenting is occurring in East Asia, with China, Taiwan and South Korea all averaging annual increases of 20% or more from 1990 to 2008.