  The development of Internet of Things (IoT) technology enables the rapid
growth of connected smart devices and mobile applications. However, due to the
constrained resources and limited battery capacity, there are bottlenecks when
utilizing the smart devices. Mobile edge computing (MEC) offers an attractive
paradigm to handle this challenge. In this work, we concentrate on the MEC
application for IoT and deal with the energy saving objective via offloading
workloads between cloud and edge. In this regard, we firstly identify the
energy-related challenges in MEC. Then we present a green-aware framework for
MEC to address the energy-related challenges, and provide a generic model
formulation for the green MEC. We also discuss some state-of-the-art workloads
offloading approaches to achieve green IoT and compare them in comprehensive
perspectives. Finally, some future research directions related to energy
efficiency in MEC are given.
