The Effect of Reduced Silver Paste Consumption on the Cost Per Wp for Tab-based Modules and Conductive-foil Based Modules

Currently Ag-paste consumption the most important cost factor for cell processing. Cell manufacturers are putting a great deal of effort into the reduction of Ag-paste usage. This leads to higher line resistances of the Ag-paste fingers and results in a trend in the photovoltaic market to apply more busbars per cell. More busbars mean more tabs in the module causing less resistive losses on module-level. In this work we perform cost-per-Wp computations using a model that treats cells and module in an integral way, based on analytical calculations. We show that the cost-per-Wp of tab-based modules can be reduced by applying lower and/or narrower Ag-paste fingers. We compare the reduced cost-per-Wp values of a tab-based module to an innovative conductive foil-based module. We show that the conductive foil-based module has a lower cost-per-Wp despite the extra cost of the foil. Furthermore, the use of lower and/or narrower fingers results in a further reduction of the cost-per-Wp values for the foil-based module as well.