This book will be a collection of the papers presented in the 2021 International Joint Conference on Energy, Electrical and Power Engineering (CoEEPE'21), covering new and renewable energy, electrical and power engineering. It is expected to report the latest technological developments in the fields developed by academic researchers and industrial practitioners, with a focus on component design, optimization and control algorithms in electrical and power engineering systems. The applications and dissemination of these technologies will benefit research society as new research directions are getting more and more inter-disciplinary which require researchers from different research areas to come together and form ideas jointly. It will also benefit the electrical engineering and power industry as we are now experiencing a new wave of industrial revelation, that is, electrification, intelligentization and digitalisation of our transport, manufacturing process and way of thinking.