As a disruptive technology

5G will open the era of internet of things by significantly promoting the quality of user experience. While providing broadband and real-time services for the entire society

the energy consumption of 5G is expected to be doubled due to the large number of data centers

edge/fog computing nodes and base stations. Moreover

the existing power supply system is unable to satisfy the diverse yet pervasive requirements on energy use. To overcome these challenges

it is imperative to design a new 5G power supply system. In this article

a software-de? ned digital energy system based on the technology of energy digitalization and informatization has been proposed and discussed

in which the traditional analog energy ?ow will be digitalized as a new internet resource. Leveraged by the technology of virtual power plant and other energy internet technologies

various digital energy services can be supported and deployed at user side

which will signi? cantly improve energy ef? ciency and save OPEX and CAPEX.