Modelling of solar power production at 65° 35′ N

Distributed generation feeds into the distribution part of the electric grid. As it is constructed with power flows going from higher to lower voltages, there might be problems with overloading and high currents, caused by more production than consumption in the area fed by a substation. To estimate the impact of generation connected to the distribution system, there is need for a statistical description of the production. Five years of data from a solar power plant in Luleå have been analysed statistically. Also, a physical model has been applied. The results show that the physical model manages to predict reasonable the data. Of the five years, one has apparently a lower production, but it is due to the lack of data. There is a marked seasonality, where the power drops considerable in September and vanishes during winter. The variation at a certain day and a certain hour is large, as the interquartile distance is about one half of the maximum power in summer. Key words. Solar power generation, power generation planning, time series analysis, extremes.