Rooftop photovoltaics perform best in spring and summer in the Arctic region, while vertical soalr perform best in autumn and winter, according to a new study 

from the University of Oulu in Finland.

  The researchers reported in "Experiences from seasonal Arctic solar PV  generation- An empirical data analysis from a research infrastructure in Northern Finland" - which was recently published in Renewable Energy - that they carried out an analysis of solar PV data from an experimental facility located in Oulu over four seasons between 2021 and 2022.

  The system consists of 24 solar panels - 12 deployed vertically and 12 installed in a typical roof configuration with tilt angles ranging from 23 to 46 degrees. All panels have an output of 275 W, are based on 60 monocrystalline cells and have an efficiency of 18%.

 According to the report, the best months for photovoltaic power generation in the Finnish Arctic are June and July. In winter, vertical photovoltaic panels outperformed roof panels by 98.36% and in autumn by 30.25%, while in summer roof panels outperformed vertical panels by 30.44% and in spring by 20.2%.

  "Extreme weather and climate conditions, significant variations in day length leading to polar nights and days, sub-zero temperatures, snow and significant seasonal temperature variations characterize Arctic and sub-Arctic regions," said the researchers, adding that the data collected provides accurate information for future investments and improves the predictability of solar simulations.

  As for the preferred tilt angle for photovoltaic panels on the roof over the two years, the research concluded that 28 degrees was the optimum angle. According to the researchers, panels with this inclination generated 3% more energy than those without, in an annual comparison.