This paper regards an experimental assessment of a smart polygeneration grid including atmospheric water generation, renewable sources and storage technology for water and cooling energy. Special attention is focused on a cooling thermal energy storage that is based on phase-change material. Moreover, the grid is managed by a devoted real-time optimization software: a specifically designed Energy Management System (EMS).
Following component modelling and EMS development activities, an experimental validation is essential, not only for the components, but also for the EMS performance during operations in a real system. Since a complete demo site is not available, the experimental approach considered in this work is based on a real-time hardware-software coupling to operate in cyber-physical mode. As previously demonstrated, it is an effective approach to have experimental results when full demo sites are not available or a direct application of new controllers could be a risk. In this case, the experimental tests presented here were carried out in the Innovative Energy Systems laboratory of the University of Genoa. In details, the test rig used in this work included a 11 kW heat pump (used for the cooling side), a 100 kWh thermal storage vessel based on phase-change material (pipes with a water/ice system), and a 30 kW electrical heater for generating the effect of the cooling demand (dissipating the cooling energy). The experimental results reported in this paper demonstrated the robustness and the effectiveness of the proposed EMS applied in a real environment, affected by disturbances and measurement uncertainties. Moreover, the tests showed significant variable cost decrease due to the application of the EMS.
