The installation occupies an area of two parking spaces, i.e. 25 m². It is composed of a PV generator made up of 15 panels located on the roof of the shade structures, with a production of 4.5 kWc, if delivered under optimum conditions. The energy storage unit, installed in the bicycle room, consists of a hybrid inverter and a second-life battery pack with a nominal capacity of 4.2 kWh.
The unit is controlled by software built into the Eaton xStorage Home system, which automatically manages the distribution of energy flows between PV production, power demand from the vehicles and the building, and the storage or recovery of the surplus. The electricity produced by the solar panels is either stored in the battery as direct current, or transformed by the hybrid inverter into an alternating current to meet the demands of the electric vehicles or the building.
In winter, the system can also make some trade-offs, recharging the battery on the public electricity grid during off-peak hours and recovering stored electricity during peak times, to minimize the impact on the public grid and reduce energy bills. The software, built into the xStorage Home system via an embedded user interface, automatically manages power flows, optimizes system operation and delivers reports. It is hosted on a secure Cloud and can be connected to the La Poste intranet in future in order to better monitor how the installation is operating. The software allows flow to be displayed in real-time on a tablet or smartphone, with the ability to access data on electricity production or self-consumption over a day, and over the previous month. The installation monitoring data also includes a calculation of consumption.