Low voltage and high energy yield thin film solar module

Abstract

The silicon thin film solar module (TFSM) is gaining popularity over crystalline silicon (c-Si) solar modules because of it's less energy consumption during production, only 1% amount of silicon is needed, superior low light performance and low temperature coefficient. The traditional silicon TFSM is all solar cells series connected configuration which can be easily achieved through laser scribing process; however, the all series connected configuration results in high module voltage (Vmpp ∼ 96V) and non-optimized module output power due to the current limit issue. To reduce the PV system installation cost, it is necessary to have the low voltage TFSM comparable to c-Si solar module. In this study, we present the development of 1.3×1.1m2 parallel-and-series connected low voltage (Vmpp∼32V) silicon TFSM, called Auria Solar C-series module (patent pending). The C-series module also passed the IEC 61646 and 61730 qualification tests by TÜV Rheinland certification. Through the analysis of the current limit issue of the silicon TFSM, we optimize the solar cell numbers to get the best module output power. The small dead zone width ∼180μm (from P1 edge to P3 edge) achieved via the precise laser scribing is also shown in this paper. The comparison of module performance between C-series module and traditional TFSM reveals that C-series module has 1.5% higher Pmpp output. The 900kWp system using the C-series module was installed in Verona, Italy; the PVsyst simulation shows high energy yield and 92.1% high performance ratio.