Two-Dimensional Hot Spot Temperature Simulation for c-Si Photovoltaic Modules

A two-step method to simulate the spatially resolved temperature of a partially shaded cell in a crystalline silicon photovoltaic (PV) module is presented and tested. First, an efficient module electronic simulation tool computes the operating conditions of a module's constituent cells. Second, a two-dimensional finite-element analysis simulation, utilizing forward-, and revers-bias electroluminescence measurements, is performed to spatially resolved cell temperature. With an outdoor experiment, un-encapsulated cell temperatures are directly measured under controlled heat transfer conditions. A peak local cell temperature of 144 °C is observed on a multi crystalline silicon cell dissipating 54 W heat in the experiment, 57 °C higher than the result from a non-spatially resolved simulation. Experimental results indicate cells without significant Ohmic shunts are suitable for temperature simulation with the aid of reverse bias electroluminescence imaging, which yields a maximum temperature prediction error of less than 15 °C. However, simulation for cells with significant Ohmic shunts is prone to underestimate the cell temperature by up to 45 °C. Multiple shading fractions from 12 to 80% lead to severe heating scenarios in such case.