Performance of grid-connected PV system in Southern Norway

This paper presents performance results from one of the first grid-connected photovoltaic (PV) systems in Norway. The 45 kWp system is mounted on top of a flat roof at the headquarters of a local utility company, Agder Energi, in the coastal town of Kristiansand. The system consists mainly of multi-crystalline silicon modules, with one thin film array. The system has been in operation since May 2011 and is instrumented for research and monitoring purposes. Data recorded include global and diffuse horizontal irradiation, tilted irradiation and other weather parameters, PV module temperatures, DC and AC current and voltage for three arrays, in addition to inverter power data and voltage quality measurements. Similar performance data has not yet been published for Norway. The results so far indicate good conditions for solar utilization at this location with global horizontal irradiation around 1065 W/(m2yr) and around 50 % diffuse fraction. The system produces as expected from a design perspective, with specific yield reaching 950 kWh/kWp and PR approaching 0.8 in 2014. Improvement in PR is seen as operational experience increases and system downtime is reduced. PR loss can be attributed to part-shading of PV arrays from the surrounding building structures, snow coverage in winter and inverter outages.