Solar modules aperture area

Fig. 8.6. Aperture area efficiency of different silicon thin film solar modules (aperture area 8 x 8 cm2) as function of light exposure time. The a-Si 11/pc-Si H tandem and i< -Si H single junction solar modules on texture etched ZnO Al were prepared at the FZJ, the a-Si H/a-Si H tandem solar module was cut from an industrially produced (0.6 m2) module...

The aperture area of a solar module is defined by the inner boundary of total laser scribed area. For every kind of series-connection, the active solar cell area is reduced by the area of the interconnection structure. Area losses increase if the cell width is reduced. On the other hand, electrical losses in contact layers become more severe with increasing cell width due to increasing cell current. Hence, optimization of the cell width must consider both area losses (dead area) due to patterning and series resistance losses due to TCO sheet resistance. These power losses can be described by the loss factors /, which is the sum of the loss factors /d (area losses) and /tco (resistive losses in front TCO) [69] ... 

Fig. 8.12. Calculated active area (gray) and aperture area efficiencies (black) of a-Si 11/jLif- Si 11 tandem solar modules as function of cell width for different TCO sheet resistance values Rtco 5 0 (dashed), 10O (solid), and 20 0 (dotted)...

The best stabilized cell efficiencies on ZnO Al obtained at the FZJ in a PECVD reactor for 30 x 30 cm2 substrates were 8.0, 8.9, and 11.2% for a-Si H p-i-n, )LLc-Si H p-i-n, and a-Si H/)j,c-Si H tandem cells, respectively [152], The best initial efficiency for pc-Si H single junction solar cells was achieved by Mai et al., who reached 10.3% for an absorber layer thickness of 1.6 J,m, which was deposited at a high deposition rate of 11 As-1 [153], Initial aperture area module efficiencies of 10.8 and 10.6% were achieved for a-Si H/pc-Si H tandem modules with an aperture area of 8 x 8 and 26 x 26 cm2, respectively [154,155]. The efficiency of the small area module stabilized at an efficiency of 10.1% after lOOOh of light soaking as confirmed by the National Renewable Energy Laboratory (NREL, see Fig. 8.29). 

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