Standardization of LCA for environmental Performance Assessment of High Voltage Switchgear: A critical Evaluation of current Challenges and Needs

SF6-free high voltage (HV) switchgear across the voltage ratings from 145 kV to 550 kV, primarily through the replacement of SF6 gas by C4F7N, a synthetic gas additive in combination with CO2 as a background gas, as the insulating and arc quenching medium. Alternative nonSF6 HV technologies such as vacuum interruption (VI) have thus far not proven to be scalable beyond the rated voltage of 145 kV. Furthermore, VI-based HV switchgear development cannot be justified based solely on global warming potential (GWP), since its significantly larger size and weight compared to its C4-FN + CO2 based counterpart unavoidably results in adverse environmental impact. This paper presents the results of an LCA of three types of SF6-free double busbar HV gas insulated switchgear (GIS) bays, namely: (i) 145 kV gas-based conventional bay, (ii) 145 kV gas-based compact bay, and (iii) 72.5 kV dry air VI-based conventional bay. These SF6-free

HV GIS bays are part of the HD Hyundai Electric GREENTRICTM portfolio. Further, the LCA results of a 145 kV dry air VI-based conventional GIS bay, estimated from physics-based scaling laws and development data, are included for comparison. The analysis is conducted with SimaPro LCA software, with integrated access to the latest Ecoinvent background database. The EN 15804:2012 + A2:2019/AC:2021 method is used to obtain life cycle impact assessment (LCIA) results in terms of 19 indicators, grouped into different product life cycle stages. The key parameters that strongly influence the product environmental performance are highlighted, and a detailed parametric study is performed to investigate the sensitivity of the

LCIA indicators to each of these parameters. Finally, the characteristic features of the prominent indicators are summarized along with future recommendations for planning and decision-making.

The product environmental performance evaluated through LCA is only one of several factors in assessing its overall market competitiveness, including functionality, reliability, and life cycle cost. It is important to note the complexities encountered when relying solely on the bill of materials (BOM) as a comparative metric between products to evaluate product carbon footprint and environmental impact, when faced with a wide variety of product and customer specifications, particularly in terms of rating differences, test duties and flexible design concepts. Further, the narrow view of considering GWP as the key metric tends to grossly oversimplify the holistic discussion of the real product environmental impact.

This study presents examples from publicly released LCA reports of SF6-free HV GIS bays highlighting multiple inconsistencies and, at times, selective presentation with limited transparency of product environmental performance. This serves as a stark warning against illformulated and poorly regulated policies that promote greenwashing resulting in a potential future risk for the stability of the European electrical network, and in turn, irreversible adverse economic and human impact. There is an urgent need for transparency, standardization and accountability in the LCA methodology and reporting process for effective comparison of HV switchgear environmental performance.