Nation's clean energy market brings new investors

US entrepreneur Tom Watson doesn't regret not investing in China over the past three decades. "Time was not on our side then," said Watson, whose company sells air filtration systems.

"But we can catch up now." Watson is in China with a US delegation seeking clean energy and environmental investment opportunities in China and India. US Assistant Secretary of Commerce David Bohigian is leading the delegation of 19 US companies.

Watson's Filter One designs and manufactures industrial air filtration systems for the likes of military bases in the United States, airlines, and aircraft and engine manufacturers such as Boeing and GE. It employs less than 50 people.