Detailed Analyses of Meteorological Time Series for the Sizing of Storages in Renewable Energy Systems - Uncertainties Related to Inter-Annual Variabilities

Activity: Talk or presentationOral presentation


Dimensioning the storage is a central issue in the layout of renewable energy systems designed for a high level of autonomy and security of supply that has to handle with the interannual variability of the site specific renewable energy flows and the load. For this, data sets covering multi-annual periods ha been called into service see e.g. [1,2]. As shown in [3,4] the challenges for the storage system can vary considerately from year to year. Analyses show that the occurrence of situations with extreme storage depletion is not strictly linked to the year showing the lowest renewable generation potential, and, in addition varies with the combination of installed renewable capacity and storage size.
This contribution should cast a light on the uncertainties in sizing of systems related to to the long-term variability of the renewables. As case study the sizing of a PV-battery system for the supply of a constant load during the summer season for the the Faroe Islands is selected. For this location, a 56-year data set of daily irradiance sums derived from cloud cover observations is available. It is used for the assessment – on a daily time scale - of the performance differently sized loss-less PV-battery systems which are designed to to cover a constant load during the summer month (here Mai to August). Under inspection is the variability of the temporal location of situations challenging the storage in dependence to the system sizing, i.e. the combinations of PV and storage capacities necessary for the complete coverage of the load.
These analyses may give addition inputs to the discussion on a probabilistic handling of the application of projected climatic conditions in future scenarios going beyond the discussion of annual averages.

[1] R. Bryce, I. Losada, A. Kumler, B. Hodge, B., B. Roberts, C.B. Martinez-anido, Consequences of neglecting the interannual variability of the solar resource : A case study of photovoltaic power among the Hawaiian Islands. Sol. Energy 167, 61–75
[2] S. Pfenninger, I. Staffell, Long-term patterns of European PV output using 30 years of validated hourly reanalysis and satellite data, Energy, 114, 1251-1265 (2016)
Period28 Oct 2021
Event titleISES Solar World Congress
Event typeConference
Degree of RecognitionInternational


  • renewable enegy system
  • sizing
  • energy meteorology
  • Renewable Energy. system Sizing