Investigation on a spectral splitting photovoltaic/thermal hybrid system based on polypyrrole nanofluid: Preliminary test

The present work developed a spectral splitting hybrid photovoltaic/thermal (PV/T) system based on polypyrrole nanofluid. This hybrid PV/T system can overcome the limitation of temperature in traditional PV/T, and achieve a high-temperature thermal output. In this system, the polypyrrole nanofluid employed in the spectral splitting filter can absorb the solar radiation that can't be efficiently utilized by PV cell unit, and convert it into medium-temperature thermal energy. The principle and methodology of the experimental system design was discussed, and the effect of particle concentration on the performance of system was investigated as well. The present work not only verifies the application potential of polypyrrole nanofluid in spectral splitting PV/T system, but also obtains some important rules on the performance. The results indicate that the temperature of nanofluid and the PV efficiency of cell unit itself increases with the particle concentration, but the thermal efficiency decreases simultaneously. The maximum overall efficiency of this hybrid PV/T system with polypyrrole nanofluid filter was 25.2%, which was 13.3% higher than that without filter. More importantly, the medium-temperature thermal energy can be harvested in such a hybrid system. Furthermore, an optimal particle concentration can probably realize a higher overall efficiency. (C) 2015 Elsevier Ltd. All rights reserved.