Knowing and predicting the available solar resources at a given location is essential for determining the potential yields of a solar plant. Precise meteorological parameters are therefore essential for the development and operation of solar power plants.
Researchers in the Qualification Department of the Institute of Solar Research determine the parameters relevant for solar power plants and analyse to what extent they influence the performance of the plants. In addition, standards and guidelines for the evaluation of solar resources are being developed to improve the quality of meteorological data.
We are mainly concerned with the following measurements and meteorological parameters:
Assessment of solar irradiance components: The accuracy of solar irradiance data is critical for resource analysis, yield forecasting, monitoring, performance evaluation and control/regulation of solar power plants. Sophisticated sensor calibrations are necessary to minimise the errors of solar irraciance measurements. We also measure and model the spectral distribution of solar irradiance. In addition, we develop new robust optical measurement methods.
Measurement of soiling: Dust deposits on mirrors or photovoltaic (PV) modules significantly reduce the efficiency of the systems. The TraCS system developed at the Institute of Solar Research enables regular measurements of the degree of soiling of mirrors in order to avoid performance losses. For photovoltaic applications, uncleaned reference cells or modules are compared with cleaned ones. Based on the measurements, we create models for the development of soiling over time. Such data sets are crucial for resource analysis and yield prediction of solar power plants. By implementing optimised cleaning strategies, yields can also be increased.
Aerosols/suspended particulate matter: Atmospheric attenuation effects and pollution are significantly influenced by suspended particulate matter. Our researchers measure their occurrence using an AERONET sun photometer, LiDAR systems and particle counters.
Short-term forecasts and investigations of dynamic effects of clouds: We use LiDAR systems and various cloud cameras to investigate the influence of clouds on solar resources. These analyses enable short-range forecasts of solar irradiance with high temporal and spatial resolution.
Wind measurements: Dynamic wind loads on collector structures and receivers also influence the efficiency of solar power plants. In order to be able to determine this effect, we carry out wind measurements with high temporal resolution.
Circumsolar radiation: Due to the forward scattering of direct sunlight, a considerable amount of radiation is contained in the circumsolar region near the solar disk. The radiation from this region is called circumsolar radiation. It is almost completely recorded as effective direct normal irrradiance (DNI), but only reaches the receiver in part via concentrating collectors. The actual DNI is therefore systematically overestimated, depending on collector type and atmospheric conditions. Therefore, measurement techniques and models are being developed to determine the circumsolar radiation and to investigate its effects on concentrating power plants.
Agrivoltaics: Combining agricultural activities with solar energy production creates a synergetic use that offers both environmental and economic benefits. Models are currently being developed to determine the optimal integration of agricultural practices and photovoltaics to ensure both maximum crop yields and efficient power generation.
Based on our research results, we offer the following services to solar plant operators: