PV-Thermal Window Breakthrough: 3.6% Efficiency, 50℃ Water, Optimizing BIPV

Researchers from Imperial College London in the UK and Karlsruhe Institute of Technology in Germany have published a study titled “A Building-Integrated Hybrid Photovoltaic-Thermal (PV-T) Window for Synergistic Light Management, Electricity and Heat Generation,” in Advanced Science. The team has developed a window using a semi-transparent amorphous silicon PV layer - the building-integrated hybrid PV-thermal window (PVTW), which can simultaneously generate electricity and domestic hot water (DHW).

PVTW consists of a semi-transparent PV layer and a selectively absorptive liquid-based thermal absorber. Only a portion of sunlight is absorbed by the PV layer for power generation, while the rest is transmitted to a 4mm thick water layer below it. The research team conducted tests on a rooftop in London at different tilt angles and compared its performance with a solar thermal window (STW) reference module lacking photovoltaic modules. Compared with an independent STW, PVTW not only provided higher hot water temperatures, but also increased thermal efficiency by 10% with increasing power generation. Tests have shown that the PVTW system can achieve a maximum electrical efficiency of 3.6% and a maximum thermal efficiency of 17.6%.

Due to the limited roof space required for installing ordinary solar panels and collectors in the building environment, PVTW technology can maximize space utilization and energy supply. The hot water generated can be used for household applications, and power generation can support the energy needs of buildings.