Precondition of the successful application of Solar drying is the economy mainly influenced by the savings and the costs. Components of savings and costs are related to the design of the solar dryer and the drying technology to be performed. Analysis of relations between the technical solutions and the economy is presented with regard to some often neglected or undervaluated effects, i.e. savings obtained by the absolute cleanness of solar energy, quality of the dried product and, the energy effectiveness of the drying process itself. Conclusions of- fer some contributions of principle to the selection of the system of solar dryer to be used, to design of solar dryers and, to direction of the drying technology 131.