© Uni Oldenburg, Meteocontrol (2012)
world-wide modeling of irradiance
Our method to determine solar radiation based on satellite measurements is well established in Europe and can be applied to data from other geosynchronous satellites. ThePVKLIMAproject examines areas in the USA, India, South-Africa, China and Japan.
As the real performance of thin-film and multi-junction photovoltaic cells is heavily dependent on the spectrum of incoming radiation, we develop models to derive spectra from the atmospheric composition and cloudiness.
© von Bremen et al. (2009)
Ideal Usage Scenarios of renewable energies
Time series of power input from renewable energies in Europe and North Africa are generated with high spatio-temporal resolution (1 h, 10 km x 10 km). Based on these time series, criteria are developed for optimizing the mix of wind and solar power and the spatial distribution of the power plants.
High-resolution data for Grid Simulation
Especially for planning and simulating micro grids with a high share in decentralized renewable energy production, we study the spatio-temporal distribution of solar radiation on a small scale (10 x 10 km) and with very high resolution (1 s, < 1 km x 1 km) and its dependency on cloudiness and atmospheric conditions.
Cloud motion from satellite images
Based on satellite images cloud motion vectors are calculated that allow for extrapolating cloud movement and thereby predicting irradiance for several hours in advance. Methods to improve the cloud motion detection, for example on the basis of infra-red images, are being tested.
Uncertainty of ensemble-predictions
Forecasting solar radiation several days in advance is based on the analysis of ensemble predictions that contain information on weather-dependent uncertainties and allow to evaluate the reliability of the forecast.
Optimizing Predictions by means of statistics
Statistics can be used to improve predictions of solar irradiance based on different models. Key aspects are the identification and processing of foggy conditions that cannot be modeled accurately by numerical weather prediction models, as well as the optimization of model combination as a function of forecast-time.
PV-Modeling and regional forecast
Based on solar power predictions tailored to a representative selection of solar energy plants with specific configurations and orientations, regional forecasts of power input are calculated by means of PV-simulation- and upscaling-models.
Shortest-term solar irradiance forecasts based on sky images
Local, high-resolution forecasts with high update rate can be processed from local camera images. The usage of fish-eye lenses allows forecast horizons up to 30 minutes. Our research focuses on methods to process images for irradiance forecasts as well as the investigation of new fields of application.
The methods developed in our research team are implemented in operational processes that generate products on different time-scales. The recent past ("yesterday") and the near future ("intra-day", "day-ahead") are of special interest in this context and the service focusses on reliability, availability, and margin of error.
Based on long-time satellite data (> 17 years), "historic" products of solar irradiance can be generated, for example for site appraisals.