Press Release

Enertis Applus+ analyses short-term albedo variability to optimise bifacial PV modules profitability

  • Albedo is the percentage of radiation reflected by a surface and it is an essential input parameter to estimate bifacial PV modules performance and profitability.
  • Enertis Applus+ conducted a comparative study analysing the variability of onsite short-term albedo and its correlation with onsite long-term albedo and satellite albedo values.
  • Results show that onsite short-term albedo matches onsite long-term data with a higher degree of accuracy than satellite measurements.

Madrid, March 19th, 2024.- Global consulting, engineering and quality control firm Enertis Applus+, with extended expertise in the renewable energy and storage sectors, investigated the variability of albedo, the percentage of radiation reflected by a surface, in short-term measurement campaigns and compared it with satellite measurements and onsite long-term measurements obtained from nearby meteorological stations. This study was carried out in collaboration with the Technological Institute for Microelectronics (TiM) of the University of the Basque Country (UPV/EHU).

Albedo is an essential input parameter for bifacial PV modules lifetime performance estimation, a factor that directly affects the profitability of photovoltaic (PV) projects.

Up to now, the reasons causing albedo variability were not well known, and it seemed to be partly random and due to several factors, such as changes on the surface due to its nonuniformity, seasonality and humidity. Results obtained in this study suggest that albedo variability is not completely random and that it increases considerably closer to the solstice in all measurement methods analysed.

As part of the study, Enertis Applus+ and TiM developed a statistical model comparing short-term measurement campaigns with long-term ones and satellite ones. This model defines the minimum number of required measurements for each surface or climate type to ensure that onsite short-term albedo matches with onsite long-term measurements with a previously defined admissible error. Therefore, this methodology allows to optimise the duration of onsite measurement campaigns according to surface type and seasonality, providing more accurate data than satellite measurements.

The developed statistical model allows not only to determine the optimum measurement number and duration, but also to provide clients with an admissible error and uncertainty factor, as well as the real degree of albedo variability depending on the time of year. This improves the accuracy and reliability of periodic, short-term albedo measurement campaigns, as an alternative to satellite measurements with a lower spatial resolution and provides a more accurate estimate of a project’s production and profitability.