he integration of photovoltaics into power grids requires increasingly better forecasts, especially with increasing capacities, because uninterrupted grid operation does not accept avoidable errors. In this context, rare meteorological events still present particular challenges. In addition to volcanic ash and Saharan dust, a solar eclipse requires the attention of grid operators, electricity traders and forecasting service providers. At the Fraunhofer Institute for Energy Economics and Energy System Technology IEE, a solution has now been developed to combine the degree of occultation with established weather forecast models specific to the location and time.