Qualitative Assessment of PV System Cable Loss and Practical Cost Optimization

Photovoltaic (PV) Systems convert solar energy to electrical energy and constitute a number of systems like Solar arrays, batteries, inverters, cables and charge controllers or Maximum Peak Power Tracking Controllers. The energy yield of the PV systems is affected by several losses that are attributed to these components. In this work all the losses that influence the performance of the PV system due to dust, partial shading, reflection, thermal, module mismatch and DC cable losses have been described in detail and the practical possible solutions for these have been described. The major thrust of this study is in the aspect of cable losses as this is the designer has control over this loss. PVsyst 6.6.7 software has been used for estimating the system losses for a designed PV system and specially the energy losses due to cable has been assessed in detail. From the results it has been observed that the losses due to cable vary from 1.8 % to 0.2 % based upon the cross section of the cable and other significant losses are thermal and mismatch losses. However, using a higher cross section of the cable leads to higher costs in the designed installation and effects the pricing of the solar power. Therefore the optimization of the cable cross section with respect to cost has been performed mathematically by taking into account all the significant costs involved and the current pricing of solar power resulting in the informed decision of the size of the cable for lower cable loss without leading to better energy yield and without any economic compromise.