[1] Asia Alternative Energy Program, Energy and Mining Unit, East Asia and the Pacific Region, World Bank #172 Xizhimennei Avenue, 100035 Beijing, China
[2] Center for Renewable Energy Development, Energy Research Institute, State Development Planning Commission Muxidi Beilijia #11, 100038 Beijing, China
[3] Clean Energy Commercialization, 1816 Crosspointe Drive, Annapolis, MD 21401, United States
[4] Princeton Environmental Institute, Princeton University Princeton, Washington Road, Princeton, NJ, 08544-1003, United States