Analysis of Measured and Modeled Solar Radiation At the Taars Solar Heating Plant in Denmark
Abstract
A novel combined solar heating plant with tracking parabolic trough collectors (PTC) and flat plate collectors (FPC) has been constructed and put into operation in Tårs, 30 km north of Aalborg, Denmark in August 2015. To assess the operation performance of the plant, detailed parameters, such as solar radiation, inlet and outlet temperature for the solar collector field, flow rate and pressure, ambient temperature, wind speed and wind direction were measured. Global horizontal radiation, direct normal irradiation (DNI) and total radiation on the tilted collector plane of the flat plate collector field have been measured in Tårs solar heating plant. To determine the accuracy of modeled and measured solar radiation in Tårs solar heating plant, monthly comparisons of measured and calculated radiation using 6 empirical models have been carried out. Comparisons of measured and modeled total radiation on the tilted surface with different methods were also studied. The results have shown that the DTU model could be used to calculate the diffuse radiation on horizontal surface and the anisotropic models (Perez 1988 model and Perez 1999 model) with only 1% and 2% disagreement with measured data respectively were the most accurate to be used for the calculation of total radiation on the tilted collector surface under Danish climate conditions only based on global horizontal radiation.
Keywords
Tårs solar heating plant, Solar radiation, Diffuse radiation, Total radiation on tilted surfaces, Measurements, Calculations