Life-cycle Assessment Applied to Photovoltaic Energy: A Review

The aim of this study is to evaluate the environmental performance of different photovoltaic solar energy systems through a review of the scientific literature concerning the life-cycle assessment applied to different photovoltaic systems and using the ISO 14040 and ISO 14044 standards. A comparison between solar photovoltaic systems and conventional systems, power generation is performed. Through the LCA the environmental impacts associated with the analyzed throughout their life cycle systems were tested. These results show, in terms of cumulative energy demand (CED), that for the case of monocrystalline silicon (mc-Si) as one of the most used raw materials, 75.8% of 5150 MJ corresponding to the manufacture of 1m2 of photovoltaic module is required. As for the environmental performance, this technology produces only 0.7 g/GWh of greenhouse gas emissions, compared to 3.7 g/GWh and 44.3 g/GWh produced from sources such as oil and coal, respectively. Photovoltaic technology generates lower emissions corresponds to Cadmium - Tellurium (CdTe) solar cells with 0.3 g / KWh of greenhouse gas emissions. First, it was found that, during manufacture of photovoltaic panels, a contribution of CO2equ emissions is mainly related to the transformation of silicon micro granular and it corresponds to 47.61% of emissions per GWP. Second, emissions are related to the assembly of the panels (18.39%) and, thirdly, casting and production of wafers (16.54% of GWP emissions).