Environmental Impact of SiC-Based Medium-Voltage Power Conversion for High-Power Renewable Energy Systems: A Cradle-to-Gate Life Cycle Assessment

Abstract

Environmental concerns arising from the exploitation of fossil-based resources in electricity generation have emerged as a pressing global issue. In order to achieve the objective of net-zero emissions in this sector, it is imperative to undergo an ecological transition, in which renewable energy sources (RES), such as photovoltaic (PV) and wind energy, assume a central role. However, the deployment of RES also necessitates the parallel operation of Energy Storage Systems (ESS) to compensate for their intermittent characteristics, thereby ensuring the stability of the power network. In the context of large-scale power plants, the construction of conventional low-voltage (LV) battery racks does not appear to be the most technologically advanced approach. Using medium-voltage (MV) racks could enhance the system’s competitiveness in terms of energy efficiency and cost. As the conversion system is a significant contributor to the overall cost of the BESS, this study analyzes DC/AC converters in order to clarify this aspect. Firstly, a comparison of the conventional LV and the proposed MV converter is presented in terms of electrical performance. Subsequently, a Life Cycle Assessment (LCA) analysis is applied to the constitutive components of the converter in order to evaluate their environmental impact based on the same delivered power (15 MVA). The findings suggest that the proposed MV DC/AC converter, which embeds state-of-the-art 3.3 kV Silicon Carbide (SiC) power modules, exhibits enhanced efficiency and a reduction in environmental impact when compared to the LV converter.