Corrections for Rotating Shadowband Pyranometers for Solar Resource Assessment

Solar irradiation data is scarcely available in regions suitable for solar energy applications. For the design of solar power plants, accurate but affordable measurements are indispensable. Accurate sensors are little appropriate for remote stations due to soiling, high power consumption and elevated costs. Rotating shadowband devices represent a prospective alternative. This paper describes new corrections for the systematic deviations of a Rotating Shadowband Pyranometer (RSP) with an integrated temperature probe. The correctional functions were developed on data from 23 different RSPs over an entire year. An average reduction of the root mean square deviation of direct normal irradiation from above 6.5% to below 2.5% was achieved.