To increase the share of distributed renewable energy resources and enable a flexible energy transaction network with customer-engaged production, innovative energy-aware service as well as real-time balancing of supply and demand, Energy Internet is proposed to integrate advanced IoT-based architectures, ICT-based end-to-end digital energy chains, customer-centric energy efficiency programs, energy-aware real-time platforms and intelligent distributed control algorithms. But how can we achieve convergence and interoperability of all these heterogeneous resources from different levels and domains? This article comprehensively discussed how IoT-enabled Micrgrids as controllable units to help achieve energy digitalization from two perspectives: one is vertical convergence from things-based communication to energy-based automation and the other is horizontal interoperability from Home Area Network (HAN) to Wide Area Network (WAN). Finally, the IoT-MGLab at Aalborg University is discussed as a specific instance to show how to establish an IoT-enabled Microgrid based platform for achieving Energy Internet.