Sustainability Improvement of C-Si PV Manufacturing through Technology Choices

The work presents the estimated CO₂-eq foot-print of PV modules produced in an integrated PV factory located in Germany based on different technologies and Bill of Material (BOM). The Life Cycle Assessment (LCA) analysis was performed using SimaPro software and background data of Ecoinvent 3.9.1, foreground data (mg-Si & poly-Si) from Fraunhofer ISE studies & internal data for the remaining production factories. The CO₂-eq foot-print for TOPCon Glass-Backsheet (G-B) and Glass-Glass (G-G) modules for a production capacity of 5 GW were calculated as 329 kg CO₂-eq/kWp and 316 kg CO₂-eq/kWp, respectively. The highest share of ≈ 30% and ≈ 20% were from the module and solar cell production factories, respectively. It is observed that the share of electricity usage for integrated manufacturing, glass production and Al frame production have the highest share of ≈ 50%, 11%-13% and 9%, respectively from BOM point of view. Comparison of different technologies indicate that the CO₂ foot-print for HJT G-G module is lower by ≈ 8% compared to TOPCon G-G module and PERC G-G module. This is attributed mainly to the reduced wafer thickness for HJT technology and also the leaner solar cell process flow compared to the TOPCon or PERC cell technology.