Visitors look at a 2.5 MW wind turbine of the Northern Power Systems during the Wind Power 2009 Conference and Exhibition in Chicago, Illinois, the United States, on May 5, 2009. The Wind Power 2009 Conference and Exhibition, taking place from May 4 to 7, featurs the lastest industry development and technologies of wind energy professionals from the US, Germany, Norway, Korea, China and so forth. [Xinhua]

Visitors visit the Vestas Wind Systems pavilion during the Wind Power 2009 Conference and Exhibition in Chicago, Illinois, the United States. on May 5, 2009. The Wind Power 2009 Conference and Exhibition, taking place from May 4 to 7, featurs the lastest industry development and technologies of wind energy professionals from the US, Germany, Norway, Korea, China and so forth. [Xinhua]