Floating Solar PV Systems Can Complement Ground-Mounted PV, Says IEA PVPS

If the projected lifetime energy yield is achieved, floating PV (FPV) systems on small inland waters, like ground-mounted PV systems, can significantly reduce the carbon emissions for electricity generation, according to a new report by the International Energy Agency Photovoltaic Power Systems Programme (IEA PVPS). 

Such FPV systems can become a valuable complement to ground-mounted PV, according to the Dutch research organization TNO which analyzes the detailed lifecycle inventory (LCI) of operational FPV in the report titled Carbon Footprint Analysis of Floating PV systems 2024.  

Published under Task 12, the report compares 2 FPV systems with different floater compositions—namely High-density polyethylene (HDPE) in Germany, and steel/HDPE floaters in the Netherlands—to hypothetical ground-mounted systems operational in Cologne, Germany. 

Both FPV and ground-mounted PV systems use the same 20.5% PERC modules made in China with a degradation rate of 0.7%/year, a performance ratio of 0.80, and 0 for both bifaciality and albedo. The only differences between these systems were related to their orientation, tilt and ground coverage ratio.    

According to the researchers, while both the ground-mounted PV systems had a carbon footprint of 1,100 kgCO2eq/kWp, the German and Dutch FPV systems were seen to have a carbon footprint of 1,280 kgCO2eq/kWp, and 1,300 kgCO2eq/kWp, respectively.  

The report writers explain that the carbon footprint of the floating PV systems was determined to be about 15% higher than that of a ground-mounted system with an east-west orientation, and around 25% higher than a ground-mounted PV system with a south orientation and optimum tilt.   

Delve deeper and the report claims the largest contribution of 60% to 70% to these carbon footprints is from the manufacturing of PV module. A shorter lifetime of the system translates to a higher carbon footprint/kWh.   

Hence, the writers recommend closely monitoring the degradation rate of the PV modules along with the performance and reliability of the overall system and its need for maintenance.    

Manufacturing PV modules within the European Union (EU) instead of China will further bring down their carbon footprint as will producing these using low-carbon electricity sources. Using recycled raw secondary materials for the support structure and recycling HDPE at the end of life, instead of incinerating, can further bring down the carbon footprint of FPV systems by over 40%, according to the recommendations stated in the report.  

However, the writers believe further research is required to understand the lifetime, performance ratio and degradation of modules in FPV systems. This understanding will eventually determine the system's performance.  

The entire report can be viewed for free download on the IEA PVPS website.  

TaiyangNews recently released its 1st Market Survey on Floating PV 2024 which is available for free download here.   

Speaking of carbon footprint that has a direct impact of making solar sustainable, TaiyangNews is set to host its 2nd Solar and Sustainability Virtual Conference on August 27, 2024. Registrations to the event are free and can be done here.