Environmental analysis of a nano-grid: A Life Cycle Assessment

Renewable energy sources are fundamental to face the problem of climate changes. Unfortunately, someresources, such as wind and solar radiation, have fluctuations affecting the electrical grids stability.Energy storage systems can be used for a smart energy management to accumulate power from renew-able sources. For such reason, these devices play a key role to achieve a sustainable electric system. Onthe other hand, they are affected by some environmental drawbacks mainly connected with the depletionof rare and expensive materials. Based on these considerations, in this study a nano-grid composed by aphotovoltaic plant, a backup generator and an energy storage system is analysed by an environmentalLife Cycle Assessment approach. A Solar Home System is designed, and its environmental profile is eval-uated considering several Lithium-ion batteries. Among them, nickel-cobalt aluminium oxide cellsresulted to be the most suitable solution for a Solar Home System (46.66 Pts/MWh). Moreover, a sensi-tivity analysis of the Solar Home System is performed and a hybrid energy storage plant integratinghydrogen and batteries is proposed to face the problem of seasonal solar radiation variability. Four sce-narios having different gas pressure levels and lifespan of the devices are considered. Results show thatcurrently the most sustainable configuration is represented by the Solar Home System, but in the future ahybrid nano-grid equipped with 700 bar hydrogen storage might be the best off-grid configuration forminimizing the impact on the environment (37.77 Pts/MWh). Extending the perspective of our analysisto future on-grid potential configurations, an efficient connection of the Solar Home System with a smart-grid is assessed as it looks more sustainable than other off-grid solutions (22.81 Pts/MWh).