Dynamic life cycle assessment of an on-field tested DC-nanogrid for the environmental evaluation of Renewable Energy Communities

Abstract

A DC-nanogrid is a small-size DC smart grid (not over 10 kW) generally for residential applications, based on a DC bus, which can interconnect different generation plants with electric storage systems and at least an inverter to supply uninterruptible critical loads. In the next future, Renewable Energy Communities are intending to serve the power system in terms of flexibility, reliability and optimal management of distributed energy storage. The DC-nanogrids are the key technologies to the smart functioning of microgrids and key factors for building Renewable Energy Communities. In this study the environmental evaluation, via Life Cycle Assessment (LCA), of a DC-nanogrid for home application (called in ComESto project nGfHA) has been carried out. The focus of the study is twofold: the analysis of the nGfHA hardware and the use of a targeted approach for the detailed evaluation of the nGfHA operation. An experimental approach based on a four days’ timeline has been implemented for the dynamic LCA evaluation of the nGfHA operations. The results highlight that the hardware of the nGfHA has secondary effects on the environmental impacts of the complete nGfHA configuration; the highest contribution to the environmental impact comes from the Li-ion energy storage, followed by PV, use phase and nGfHA hardware. Nevertheless, a sensitivity analysis shows that an extended lifetime of energy storage leads to equivalent environmental performances.