This special issue is going to include selected high quality peer reviewed articles from 5th International Conference on Energy Economics and Energy Policy (ICEEEP 2021, April). The prosed special issue is aiming to publish high quality research articles covering techno-economics aspects of sustainable energy systems and feature clean energy technologies and its implications on developing sustainable energy policies for achieving the UN’s sustainable development goals. The key topics are going to cover technological, economical and policy aspects of sustainable energy generation and effective utilization. It covers the sustainable integrated energy system (e.g. renewable energy technologies, energy storage, smart grid, design and control strategies for clean energy technologies, grid integration of environment friendly energy technologies, etc), combined heat and power system, sustainable transport, smart cities, energy environment, energy efficiency and management, etc.