Performance study of a new type of transmissive concentrating system for solar photovoltaic glass curtain wall

There are many problems in Building Integrated Photovoltaics (BIPV) system, such as contradiction between daylighting and electricity generation, unable to match the demand of light control, need to constantly adjust angle for tracking, and so on. A new type of transmissive concentrating system for glass curtain wall is proposed which can improve the performance of solar photovoltaic glass curtain wall. The concentrating characteristic was studied by a series of comprehensive simulation and experiment. The optical software is used to simulate the influence of concentrating characteristics in different incident angles. Compared with solid and trapezoidal structure compound parabolic collector, the concentrating performance of hollow with water structure is also simulated. Simulation results shown that the receiving rate of hollow with water compound parabolic collector is changing slowly when incidence angle is increasing between 0 and 20 degrees, and it can achieve 70% when the incidence angle less than 20 degrees, and it is better than other concentrator with different cross section shapes. Based on simulation results, the experimental samples were processed and tested in a typical sunny weather. The experimental results were in good agreement with the simulation results. The system had a minimum transmittance of 28.2% at noon, but before 9:40 AM and after 15:40 PM, the transmittance exceeds 55% and can meet lighting requirements of rooms. It can be proved that the new system has passive light control function, which is expected to replace the double-layer vacuum glass curtain wall that is widely used nowadays.