Performance Investigation On Semi-transparent Monocrystalline Silicon Photovoltaic Fa?ade Under The Influence Of Building Shadow

The combination of photovoltaic power generation and construction is a common form of renewable energy utilization currently.In particular,the photovoltaic curtain wall is used as a modern building envelope to fully utilize the vertical surface so lar radiation.The semi-transparent monocrystalline silicon photovoltaic facade has the advantages of good light transmission,stable performance and long service life.But it is often blocked by buildings so as to be under the shadow during work,which ea sily leads to system mismatch and makes the power generation efficiency of the system drop significantly.At the same time,the photovoltaic cell will also produce hot spot effect,which will reduce the reliability of the photovoltaic syst em and shorten the service life.This study focuses on the electrical and thermal properties of semi-transparent crystal silicon photovoltaic facades in natural eaves shadows and artificially set local shadows.By setting up an experimental test platform in Changsha,the performance test of semi-transparent monocrystalline silicon photovoltaic facade under different working conditions was carried out.And the effect of shadow on the performance of semi-transparent monocrystalline silicon photovoltaic facade was studied.Then the relevant conclusions about electrical performance and thermal performance of photovoltaic facade under different working conditions was obtained.The main research contents and results of this paper are as follows:Firstly,the working principle and power generation model of the photovoltaic cell are introduced and the performance parameters of the semi-transparent crystal silicon photovoltaic facade under standard test conditions are provided to obtain the five parameters under the standard conditions.On the basis of the five parameters of the standard condition,the correction method of the five parameters of any working condition is obtained.The effect of local shading on the output characteristics of photovoltaic modules is also explained.Secondly,a semi-transparent monocrystalline silicon photovoltaic curtain wall experimental test platform was built,and the measurement data,measuring instruments and measuring point arrangement of the experiment were expounde d.Then the experimental scheme was introduced.In addition,the process of simulating experiments using Ecotect software is described.Finally,the results of semi-transparent monocrystalline silicon photovoltaic facade system are analyzed and analyzed under the natural eaves shadow conditions and artificially set shadow conditions in summer.With regard to the electrical characteristics of the semi-transparent monocrystalline silicon photovoltaic facade,the experimental results show that the power generation performance of the photovoltaic curtain wall system is significantly reduced under the influence of artificially set shadows.Under the influence of artificial shadow,the percentage of power generation reduction of the photovoltaic facade system is at least 30% and the highest reaches 67.85%.The hourly power generation efficiency is basically less than or equal to 9%;under the influence of natural shadows,the percentage of power generation reduction of photovoltaic facade systems is up to 32.13%,and the power generation efficiency of time-lapse is basically greater than 9%.With regard to the I-V characteristics of the semi-transparent monocrystalline silicon photovoltaic facade,the experimental results show that the effect of artificially setting the shadow and the natural shadow of the eaves on the I-V curve and the P-V curve of the photovoltaic facade system is quite different.Under the influence of artificial shadow,the I-V curve of the photovoltaic facade appears “multi-knee” shape,the PV curve has multiple peak points,and the selection of the maximum power point is different under different experimental conditions;the I-V and P-V curves of the semi-transparent monocrystalline silicon photovoltaic facade under the eave shadow are basically the same as those under normal conditions.The IV curve is a "one knee" shape,and the PV curve has only one peak point.With regard to the thermal performance of semi-transparent monocrystalline silicon photovoltaic facade,the experimental results show that the maximum temperature of the shadow photovoltaic cell under artificially set shadow conditi ons is above 42 °C.And when a cell is blocked 75% of the area and another is blocked 25% area under artificially setting the shadow condition,the shadow photovoltaic cell is reverse biased at noon.As the power consumption of the load,the shadow cell temperature is significantly higher than the non-shadow cell temperature,and the maximum temperature value is the largest among all experimental conditions.But due to the protection of the side diode.,the shadow cell does not cause a hot spot effect.The fill factor value is less than 60% under the influence of artificial shadow.That means local shading makes the quality of photovoltaic cells worse.Under the influence of the natural shadow of the eaves,the maximum temperature of the shadow photovoltaic cells is lower than 41 °C,and the fill factor values are 66% and 82%,respectively,all in the range of 0.6~0.85,indicating that the quality of the photovoltaic cells is good at this time.In this study,the electrical and thermal properties of semi-transparent monocrystalline silicon photovoltaic facades under the influence of architectural shadows were studied.The research results provide reference for the design and optimization of translucent monocrystalline silicon photovoltaic curtain wall systems.