The aim of this chapter is to describe the use of satellite-derived surface solar irradiance (SSI) from the continuous optical image acquisition of geostationary meteorological satellites to produce solar power forecasting, typically for intraday time horizons from 0 to 6 h ahead. Different approaches and products of satellite-based SSI retrieval used for solar power estimations are first presented. Then two families of satellite-based solar forecasting method are described: The one considering only the temporal variability of SSI observed in quasi real-time by the satellite for a single location or an aggregated region. The one exploiting the ability of the satellite to observe the correlated spatial and temporal variability of SSI (cloud motion vectors or statistical approaches). The different possibilities of using in situ SSI or solar power monitoring in combination with satellite are also presented.