Differences in temperature and irradiance variations in no 'dramatic' ways adversely impact the performance of perovskite solar cells. Even though the efficiency of the cells may come down slightly during the day, it recovers during night. These findings by the École Polytechnique Fédérale de Lausanne (EPFL) of Switzerland helped the scientists quantify the energy yield of perovskite devices under realistic conditions when these were tested within the lab.
The research team led by Wolfgang Tress of the lab of Anders Hagfeldt at EPFL along with colleagues from the lab of Michael Grätzel re-created real-world temperature and irradiance profiled from specific days into the laboratory environment using data from a weather station near Lausanne. This approach helped them reach an understanding about the potential of perovskite solar cells in varying and actual weather conditions.
Pointing out the fact that stability of perovskite devices acts as a major deterrent in the commercialization of the technology, the scientists said outdoor tests show that encapsulating these cells to protect them against extreme weather conditions is not a very good idea since encapsulation only addresses parasitic failure mechanisms that may not be related directly with perovskite itself.
At the same time, testing these cells in the lab has its own limitations as these do not factor in real-world variation in irradiance and temperature. Hence, devising a way to create real-world conditions within a lab setting helped the team build a case for the technology.
"The study provides a further step towards the assessment of the performance and reliability of perovskite solar cells under realistic operation conditions," said Tress. Findings by the team were published in the journal Nature Energy on June 17, 2019.