This book is a collection of research findings presented at 2023 2nd International Joint Conference on Frontiers of Energy and Environmental Engineering (CFEEE 2023), held in Sanya, China on September 1-3, 2023. The conference was co-organized by Hainan Institute of Zhejiang University, Sanya Global Energy Research Institute, South China University of Technology, IEEE PES China Satellite Technical Committee - Smart Buildings, Loadsand Customer Systems, and supported by CoreShare Academy Exchange Center. The book covers topics including Planning, Operation, Economics and Market in Modern Power Systems, Renewable Energy, Energy Storage, Advanced Power System Technologies, Electric Vehicle, Integrated Energy System, Energy Internet, Environmental Analysis and Monitoring, Energy Security and Clean Use, Environmental Pollution and Pollution Control. The contributions from leading experts in the field highlight innovative solutions and strategies developed to address pressing global challenges. It offers valuable insights into the latest technologies and future directions of the frontiers of energy and environmental engineering fields, making it a must-read for researchers, practitioners, policymakers, and students interested in these fields.