Long term university-administration collaboration for assessing solar radiation resource in Catalonia

The Catalan Institute for Energy (ICAEN) is a public corporation of the Government of Catalonia whose mission, since 1991, is the promotion of energy efficiency and renewable energies, the elaboration of energy planning and policies of Catalonia, and the compilation of energy statistics. In particular, and with regard to solar energy, ICAEN established a solar radiation measurement network across the country and has kept it in operation until the present. This network includes 10 stations devoted to the measurement of global and diffuse radiation. Based on the data collected, which is made available on demand to interested users, two versions of Solar Radiation Atlas in Catalonia have been prepared in the past (1995, 2000). The maintenance of the stations, the updating of instruments and data loggers, and the processing of the data has been performed, over time, with the collaboration of academic institutions: the Universitat Politècnica de Catalunya, between 1990 and 2021; and the Universitat de Girona, from 2022 to the present. Researchers from these universities have provided their expertise in solar radiation and climatology. In addition, several selfless collaborators have taken care of each station. Currently, traditional Kipp&Zonen CM11 pyranometers (or similar models), one of which in each site is installed with a sun band for the measurement of diffuse radiation, are being replaced by DeltaLink SPN1 instruments that simultaneously measure global and diffuse radiation and upload the data, in real time via the internet, on a central server. All historical data are currently being reanalyzed with stricter quality control and a new Atlas of solar radiation in Catalonia is being drawn up. In summary, this long-term collaboration between university and administration is an example of success, resulting in very long (over 30 years in some cases) solar radiation data sets of high quality and with notable spatial density (1 station every 3000 square km approximately).