Estimating climatological variability of solar energy production

•We estimate climatological variability of solar energy production.•We introduce MERRA reanalysis as a data source for photovoltaic power modelling.•The estimation is based on 33 years of simulation with hourly time step.•Resulting estimates also include quantiles of monthly and yearly power production.

A method is presented for estimating the climatological variability of yearly and monthly photovoltaic power production per 1 kWp of installed power. This quantity is computed for a specified portfolio of sources on the basis of historical data. Its climatological variability is derived from a simulation of 33 years of power production with hourly time step. Underlying meteorological variables are taken from the MERRA reanalysis for the years 1979–2011. Since the MERRA reanalysis is not a traditional data source for photovoltaic power modelling, various comparisons to available and more frequently used data sources are included. The method of estimation has the advantage of wide applicability due to the global coverage of the meteorological data.