Water-floating solar photovoltaics (FPV) add to renewable energy capacity building without additional land requirements. We quantify the environmental impacts of FPV on inland water bodies with a focus on greenhouse gas (GHG) emissions and water consumption. We harmonize and compare all existing peer-reviewed life cycle assessments on FPV and add two case studies. We consider the full life cycle of FPV, including future (prospective) material recycling options, as well as changes in water evaporation and aquatic GHG emissions at the FPV location. On average, we computed an overall GHG footprint of 36 gCO2 kWh–1, similar to ground-based PV. Biogenic aquatic GHG emissions at the FPV location are expected to contribute a relatively minor share (1%–8%) to the GHG footprint of the FPV systems. Water savings due to prevented evaporation are much higher than the FPV systems’ water consumption. Collectively, our findings support the continued development and deployment of FPV technology to aid the transition toward renewable energy supply.
Seitz et al. (Mon,) studied this question.