10:30 AM - *ES08.04.01
Aging Models of Environmental Stress Factors for Solar Mirrors Lifetime Prediction
Olivier Raccurt1,Coralie Avenel1,2,Sandrine Therias2,Jean Luc Gardette2
Univ Grenoble Alpes, CEA LITEN1,Univ Clermont Auvergne – CNRS – SIGMA Clermont, ICCF2
The durability of solar mirrors is a critical factor for the deployment of concentrating solar power (CSP) plants [1,2]. Accelerated aging models currently applied in the polymer, electronic and photovoltaic fields have recently been reviewed , and the issues of their application to solar mirrors have been discussed. Lifetime prediction of solar mirror requires determining the kinetic laws of the degradation related to the stress factors level and the associate models. Temperature and humidity has been identified to be major stress factors for solar mirrors [4-6]. Accelerated aging in temperature and temperature with humidity at different levels were performed to assess the dependent parameters of models selected from the literature. Results from three different mirrors technology will be presented and analyzed to extract kinetics parameters for models. These parameters include the apparent activation energy for the Arrhenius temperature law, the Peck and Eyring coefficients for humidity. The experimental values were then assessed for specular reflectance loss of solar mirrors. Finally, using these parameters, acceleration factors were calculated for solar mirrors. An effective temperature taking into account the Arrhenius degradation law was used rather than the commonly used mean temperature. The relevance and utility of this effective temperature compared to a simple mean have already been discussed in the literature [7-9]. The problem of coupling all previous laws together is also addressed. Finally, a calculation of acceleration factor related to different CSP sites around for standard damp heat test (85°C, 85%RH) will be presented and discussed.
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