Experimental investigation and annual overall performance comparison of different photovoltaic vacuum glazings

Abstract

Photovoltaic vacuum glazing is a novel choice for low-energy buildings that can generate electricity and reduce air conditioning load. To stimulate the overall performance of such glazing, a further integration of an air layer is proposed and investigated in this study. Hollow photovoltaic glazing, photovoltaic vacuum glazing and hollow photovoltaic vacuum glazing are evaluated through experiments and numerical simulations, with double glazing as the baseline. A test rig is built for both indoor and outdoor experiments to study the thermal and electrical performance of different photovoltaic glazing. Physical parameters including thermal conductivity, optical and electrical properties are measured. A simplified heat transfer model is proposed based on detailed thermal analysis and reasonable assumptions. The model is verified against the experimental data, proving the adequate ability to accurately predict the performance of photovoltaic glazing with various structures. In this context, the climate suitability is analyzed for targeted glazing in terms of heating load, cooling load and power output. Results show that hollow photovoltaic vacuum glazing performs better if the Low-E coating is applied in the vacuum gap rather than in the air gap, and outperforms photovoltaic vacuum glazing in severe cold regions while being comparable in other areas.