Durability of anti-reflective coatings for parabolic trough receivers

Anti-reflective coatings are employed on both sides of the glass envelope tube of evacuated parabolic trough receiver tubes to minimize reflectance losses. This paper reports the measured initial transmittance values of seven different receiver tube manufacturers as well as the degradation rates after accelerated aging, outdoor exposure and in- service testing. The presented data represents a summary of measurements carried out in the OPAC laboratory at Plataforma Solar de Almería in the period between 2013 and 2019.