Unveiling lifecycle carbon emissions and its mitigation potentials of distributed photovoltaic power through two typical case systems

With increasing global energy demand and the worsening climate change, photovoltaic (PV) power systems have attracted increasing attention as a dominant clean energy option. However, few studies systematically examined the whole lifecycle carbon emissions and reduction potential of PV systems, especially the distributed PV systems. Thus, this study is designed to quantify the whole lifecycle carbon emissions and reduction potential of two typical PV power systems in Zhuhai (Z-2.4) and Macao (M-4.5) by using life cycle assessment method. The results show that the whole lifecycle carbon emissions of Z-2.4 and M-4.5 are -17894.1 (impact: 4079.6; benefit: 21973.7) and -19629.6 (impact: 2090.4; benefit: 20720.1) kg CO2 eq./kW, respectively. Due to the production of energy storage batteries and aluminum materials, the PV solar cell materials are the main contributors to carbon emissions for both Z-2.4 (3967.9 kg CO2 eq./kW) and M-4.5 (2065.1 kg CO2 eq./kW). In terms of use phase, the annual carbon emissions of Z-2.4 and M-4.5 are -862.9 and -722.8 kg CO2 eq./kW, respectively, due to avoiding the raw electricity usage. It is found that carbon emissions offset by PV systems make more than 70 % (Z-2.4) /90 % (M-4.5) of its service life clean production.