This paper studies the design and management of a distributed energy system incorporating renewable energy generation and heterogeneous end-users from residential, commercial and industrial sectors. A hierarchical framework is first proposed for the energy demand side management through peer-to-peer exchange of energy information in the real-time market. The heterogeneity of demand flexibility associated with different types of users is reflected in the framework with inter-sectorial interactions modelled by a non-cooperative game. The inherent uncertainty of renewable generation is also considered with the technique of receding horizon optimization. Subsequently, smart contracts and decentralized identifier guaranteed by blockchain technologies are implemented to create a seamless, secured and efficient distributed energy system. Finally, a Singapore-based case study is conducted and the results show that with effective interactions among participants, electricity consumption of the entire energy system closely tracks the generation pattern of renewable resources, resulting in a significantly flattened schedule of grid electricity procurement.