Performance Assesment of a Solar PV-Grid Connected Installation in Ås, Norway

Abstract

The Norwegian government is committed to increase the renewable energy share of the Norwegian primary energy consumption to 67.5%, and to increase the share of energy in transport to 10% renewable by 2020. In order to achieve these targets, investment in renewable energy resources such as wind and solar energy is essential. Even though observation of solar irradiation show that the solar resource in the south-eastern parts of Norway is better than earlier believed, less focus has been placed on utilization of solar energy resource in Norway. In this study, the results obtained from field monitoring the performance of a 2.07kWp photovoltaic grid-connected system installed at the Norwegian University of Life Sciences, Ås, Norway, is presented. The PV-system is mounted on the flat section of the roof of a laboratory building at the Department of Mathematical Science and Technology of the University. Detailed performance measurement of the system started in February 2013, and still on going. However, the analysis presented in this study consists of the data recorded between March 2013 and February 2014. The electricity generated by the system is fed directly into the grid. The in-plane irradiance, array power output, system power output and other parameters are measured and averaged every 1-minute by a data logger integrated in the inverter. The measured data was utilized to estimate the reference yield, array yield and final yield, as well as other performance parameters of the system. The specific yield of the system through to recording period was found to be 931.6kWh/kW-year. The monthly average array yield varied between 0.04kWh/kWp-day in January and 4.8kWh/kWp-day in July, with an overall average value of 2.73kWh/kWp-day. The monthly average final yield was found to vary between 0.02kWh/kWp-day in January and 4.5kWh/kWp-day in July, with an overall average value of 2.54kWh/kWp-day. The overall annual capacity factor, performance ratio and system efficiency are 11%, 83% and 13%, respectively. The findings from this study show that the performance of this system is comparable with similar systems installed in northern Europe.