  This paper presents the results of long-term experiments conducted on
fixed-tilt (FT) and single-axis tracked (SAT) open-rack photovoltaic (PV)
modules in South Africa. Utilizing Faiman's heat dissipation model and data
filtering method, the study demonstrates favourable comparisons of FT
experimental results with literature, while yielding novel heat dissipation
factors for SAT modules. Enhanced heat dissipation is observed in no/low wind
conditions for SAT modules compared to FT modules. Analyses reveal the
influence of plane-of-array (POA) irradiance, wind speed and direction on
module temperature, with SAT modules exhibiting greater heat dissipation
stability. An investigation into data filtering methods suggests minor
sensitivity for both configurations, with a slightly more pronounced impact on
SAT modules. Assessments comparing module temperature predictions using diverse
heat dissipation factors for FT modules reveal negligible sensitivity. This
suggests that exact heat dissipation factor values may not be crucial for
accurate predictions of module temperature in FT open-rack systems. Annual
power output simulations using PVsyst software demonstrate a 2.9% and 3.3%
enhancement for FT and SAT configurations, respectively, when employing
experimentally determined heat dissipation factors. These findings highlight
the importance of realistic, configuration-specific heat dissipation factors in
optimizing PV system performance, particularly in the competitive context of
modern PV power plant construction and techno-economic calculations.
