Study on shaded factor of balcony wall solar collector unit

After solar collector unit integrating into balcony of high-rise buildings with large tilt angle (≥60°), the lower solar collector unit will be shaded by the upper one. The calculation model of the daily shaded factor has been developed in this paper. Daily shaded factor of representative days in summer months has been calculated by using this model and the daily shaded factor variations with latitude, tilt and azimuth have been analyzed and discussed. The results show that the maximal daily shaded factors of representative days in summer months appear at due south and they are approximate symmetrical distribution between East and West directions. Daily shaded factors and average shaded factors of summer months change smoothly at the azimuth angle range of -20°, 20°. Daily shaded factors decrease with the latitude and tilt angles increase. When solar collector units used at 20° N are integrated into the balcony at 60°, their maximal daily shaded factor is around 0.34; the daily shaded factors do not exceed 0.087 if the latitude equals to 35°. For all summer months, the average shaded factors are below 0.173. The azimuth angle should be controlled in -20°, 20° because large azimuth angle will reduce solar energy absorbed by the solar collector unit. For the sake of engineering applications, correlations with a high correlativity (R2≥0.99) of average shaded factors and azimuth angles have been given in this paper.