Carbon, materials and energy footprint of a utility-scale solar plant in Aotearoa New Zealand
Isabella Pimentel Pincelli, Jim Hinkley, Alan C. Brent
Abstract
Photovoltaic (PV) technologies have evolved over time for higher efficiency, with the adoption of larger wafers, passivated emitter and rear cells (PERC), and bifacial panels. The advancements in the production of PV components call for updated life cycle assessments (LCAs) of PV systems. We undertook a LCA for a utility-scale solar plant in Aotearoa New Zealand using monocrystalline silicon PERC bifacial panels, establishing the carbon, materials and energy footprint associated with the life cycle stages of the solar farm and its components. By comparing different databases for silicon processing up to the wafer slicing our results show that the GHG emissions of utility PV systems are lower (26.2 gCO2eq/kWh versus 40.4 gCO2eq/kWh), and the Energy Return on Investment (EROI) is higher (38 versus 20) when using updated databases, which reflects the advancements in the silicon processing activities. Nevertheless, the production of PV modules continues to be the greatest contributor to the life cycle GHG emissions of the utility-scale PV system (contributing to 51.6 % of the total emissions). Further recycling of the materials from the components of the solar farm reduces emissions moderately. This study underscores the significance of updating LCAs for PV systems, which provide insights for further improvements within the system and guidance for decision makers regarding the adoption of PV systems.