This article analyses the diffusion and adoption of solar energy conversion systems in Greece during the last forty years. The installed capacity of solar thermal and solar electricity systems and the effects of the policies implemented during this period are analysed. Furthermore, the contribution of solar conversion systems to the energy security of Greece and to the reduction of greenhouse gases and other air pollutant is assessed on an annual base. Different solar technology market penetration, solar system technological changes and demographic changes in association with the climatic conditions in all regions of the country have been taken into account in order to estimate the energy conservation and emissions reduction. The results show that the conserved energy reaches 2% of the gross inland consumption while the abated CO2 emissions are also substantial. (C) 2017 Elsevier Ltd. All rights reserved.