IFAC - CONFERENCE ON CONTROL METHODOLOGIES AND TECHNOLOGY FOR ENERGY EFFICIENCY 29/03/2010 Vilamoura, PortugalA family of models that can be applied to various types of renewable energy plants is proposed. The methodology is used to model a solar plant for the production of sanitary water (the hot water production system installed at the “Hospital Universitario Virgen del Rocío”, Seville, Spain). A detailed examination of the behavior of the plant has produced a model which has served to identify niches of inefficiency in the operation. The model is later used to tune the parameters of a controller to improve operation.Ministerio de Ciencia y Tecnología DPI 2007-66718-C04-01Junta de Andalucía TEP-0272