The book contains select proceedings of the International Conference on Smart Grid Energy Systems and Control (SGESC 2023). The proceedings are divided into 02 volumes, and this volume focuses on the Decarbonisation and Digitization of the Energy System. The book covers the important topics on the smart grid/microgrids and control aspects, optimal energy scheduling, distributed generation, wind energy for remote electrification, forecasting of loads and daily energy demand, reactive power management, Volt-Var control, reactive power procurement, and ancillary services, the role of FACTS devices for reactive power management and control, feasibility study of PV/Wind hybrid systems, electricity markets, stability of the power system network, energy storage systems and electrical vehicles. This book is a unique collection of 27 chapters from different areas with a common theme and will be immensely useful to academic researchers and practitioners in the industry.