This paper describes the methods for forecasting solar irradiance by using geostationary meteorological satellite (GMS) images. As the first attempt the authors forecasted the cloud albedo for a basic study of irradiance estimation by estimating the driving drift vector of clouds using GMS images. A new procedure is also proposed for removing the effect of ground albedo, which disturbs cloud movement analysis. This time, annual forecastable probability was estimated as 81.3% for Ih ahead, 71.0% for 2h ahead and 59.3% for 3h ahead, (C) 2001 Published by Elsevier Science B.V. All rights reserved.