The framework, developed as part of the EnrgyVille collaboration, has a higher accuracy compared to previous approaches by computing the energy yield of the individual cells and modules based on local and varying meteorological conditions and the way it is influenced by module frames, system components’ geometry, and varying albedo.
To enable implementation of advanced optical simulations (using ray-tracing) at system level, special care was also taken to optimize the computational flow and still operate quickly.
“An important achievement is that our tool will be capable of calculating the energy yield of an entire system, while maintaining a low error margin of < 5% (daily RMSE) even in complex scenarios and at high speed of calculation," said said Eszter Voroshazi, R&D manager of PV modules and systems at imec/EnergyVille. "The impact of technological and system configuration details on the non-uniformity at the rear side of the modules has a surprisingly important effect and can trigger major losses up to 40% due to mismatch between modules, hence we pursue the further development of our simulations combining a physics-based approach with high performance computing techniques."
"Our final goal is to calculate with high precision the bifacial gain at module, string and system level and enable a multi-objective and automated PV power plant design tool on
the longer-term,” he added.
Bifacial PV systems can annually generate 5 to 20 % more electricity than their traditional monofacial counterparts on little or no extra cost. Because of this benefit, bifacial PV installations are gaining market share. However, the limitations of the current simulation tools to precisely determine their expected energy yield could hinder further deployment as the data is not accurate enough for investors.
While the existing commercial energy yield simulation tools and approaches used for the design of PV power plants have become more and more precise for standard monofacial silicon solar modules, their estimations for bifacial systems still include high error margins. Calculating the energy yield of bifacial solar modules is more challenging because energy generation from light received at the rear side depends on many variables that are hard to determine and may vary during