On off-grid green solar panel supplied edge computing

We consider the case of a group of communicating edge nodes only supplied with photovoltaic (PV) panels. This configuration makes the deploy green if all the data is elaborated locally, but a minimal (if nothing) communication with a remote server. This model has several characteristics. Since the amount of storable energy is limited by the battery capacity, the solar energy at an edge node with fully charged battery cannot be further accumulated, which is an indirect source of inefficiency. On the other hand, the energy consumed by edge nodes is tied to the activity of the nodes. Roughly an edge node in an idle state consumes less than one third of the power consumed when elaborating data, while the energy cost to move data among the edge nodes is usually less than the one required to elaborate them (which is the case in many applications). As a consequence an edge node which is running out of green energy can conveniently offload its computations to energy richer nodes in idle states. This paper reports some preliminary results of this form of green cooperation.