1. State Grid Hebei Electric Power Co., Ltd., Shijiazhuang 050057, China
2. Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, China
3. Development Research Center of State Grid Hebei Electric Power Co., Ltd., Shijiazhuang 050057, China
4. Department of Management Science and Engineering, Central University of Finance and Economics, Beijing 102206, China
5. China Forestry Group Corporation, Beijing 100036, China
6. CSCEC-TAISEI Construction, Ltd., Beijing 100029, China
7. Institute of Energy, Environment and Economy, Tsinghua University, Beijing 100084, China