This work provides a review of dye solar cell long-term stability under light and thermal stress factors as well as discussion on the main degradation mechanisms. Performance and EIS parameters of industrial type Z907-based cells were evaluated during the course of continuous light soaking over 25,600 h at 55-60 degrees C. Only minor degradation occurred under such conditions, with open circuit voltages dropping by 50-80 mV due to a shift of the conduction band towards more positive potentials and with fill factors at high light levels decreasing due to an increase of cell series resistance. There is no evidence of dye degradation, loss of iodine or decrease of Pt electro-catalytic activity. From the accelerated ageing tests, a product life time of 40 years can be extrapolated for Middle European and 25 years for South European conditions. 80 degrees C storage over 1000 h resulted in 10-20% decrease of performance with ionic liquid or solvent based electrolyte systems, respectively. (C) 2010 Elsevier Ltd. All rights reserved.