Analysis of the efficiency and performance of half-cell solar modules

Abstract: Solar photovoltaic energy has gained great importance in the last couple of years, as its costs getlower and the total installed capacity increases. As a result of this, new technologies are arisingwithin the field, with the objective of increasing performance and reducing costs. One of themis the half-cell solar modules which, among other advantages, are said to perform better undershaded conditions compared to standard modules.This project checks the veracity of this statement. For that, a Matlab/Simulink model capable ofrepresenting the behavior of the JAM60S21-365-MR solar module has been created, andexperimentally calibrated with measurements performed in an actual panel. After the modelaccuracy has been checked, it has been used to simulate various shaded scenarios for standardand half-cell modules, to carry out an equivalent comparison between the two.The results for the model show a maximum error of 0.62% for the reference case, and of 6.06%for the worst 4-module-string simulation. This has been found to be an acceptable error, whichis created mainly as a result of temperature measuring inaccuracies and the rough estimation ofsolar cell model parameters. To reduce it, it is recommended that these issues are addressed.Which module does better under shading has been found to be dependent on multiple factors:The temperature and irradiance at which the module operates, its constructive parameters, thenumber of series or parallel connected devices and the shape and size of the shadow. This lastone is the one with the biggest impact in electrical power output. Because of it, the most usualcases for shadowing in PV facilities have been compared. For equivalent modules, shading in thedirection of the string of a single cell is less detrimental in half-cell modules; however, if thatshadow covers a whole row, it is equally damaging. If a full cell is 50% shaded in this scenario, a20% less power is lost in the half cell module compared to the normal one. On the other hand,shadowing in the direction on the bypass-diode line tends to slightly benefit standard modulesfor equal cell parameters if the shadowed full-cell percentage is below 50%, for both cell androw shading. However, as this value increases, half-cell modules tend to gain an advantage overstandard ones.