Life-cycle assessment of solar fasades - The role of ethylene tetrafluoroethylene in building-integrated applications

The present article sets out to investigate two fasade-integrated systems with organic photovoltaics and ethylene tetrafluoroethylene, based upon life-cycle assessment. The proposed systems have been designed and experimentally evaluated at the University of Lleida, in Spain. The analysis involves two electricity mixes (Spanish; French), two cities (Barcelona; Paris), optimistic and pessimistic scenarios. In most cases, the energy-paybacktime values are around 1-2 years, i.e. lower in comparison to system lifespan (10 years). Energy-return-oninvestment values range from around 3 to 21. With regard to avoided greenhouse-gas emissions (lifetime), the results show around 1 t CO2.eq/kWp in Paris and about 5 t CO2.eq/kWp in Barcelona. Considering the Spanish electricity mix, the proposed solar systems offer: 1) avoided greenhouse-gas emissions which range from 76 to 157 kg CO2.eq/year, 2) avoided energy-demand impacts which, in most cases, are higher than 1500 MJprim/year, 3) avoided ReCiPe impacts which vary between 1.4 and 6.2 Pts/year (depending on the impact category). Results based on USEtox and Ecological footprint are also presented. Regarding limitations, the present study has been based on certain assumptions, embodied energy/embodied carbon, etc. Concerning future prospects, the proposed life-cycle model would be extended in order to include additional environmental indicators and methods.