Energy Rating for Evaluating Performance of Perovskite and Perovskite-on-Silicon Tandem Devices in Real-World Conditions

We present an independent analysis of expected real-world performance of single junction perovskite cells and tandem perovskite-on-silicon devices relative to single junction silicon cells. As energy-rating of perovskite devices is not yet realised and the technology is still rapidly maturing, this is a theoretical study. We create an “optimistic” scenario, which represents successful upscaling of current record-efficiency perovskite lab cells. Our model considers temperature, spectral, angular and junction mismatch effects. In this scenario, we find that single-junction perovskite cells perform better in many real-world climates than under standard test conditions; in one climate, the single junction perovskite cell has a higher absolute energy yield than a silicon cell that had 3 % higher efficiency under standard test conditions. For tandem cells, we find that tandem energy gains of between 29 % and 40 % are achieved when the band gap of the front cell is optimised to the climate. We also simulate less optimistic scenarios by reducing the performance of both the perovskite or silicon sub cells. We find that tandem energy gain is strongly affected by the initial choice of sub-cell efficiency, which largely explains the large variations in published modelling studies.