Optical losses of solar mirrors due to atmospheric contamination at Liberal, Kansas and Oologah, Oklahoma
An assessment is presented of the effect of outdoor exposure on mirrors located at two sites selected for potential solar cogeneration/repowering facilities: Liberal, Kansas and Oologah, Oklahoma. Mirror coupons were placed on tracking heliostat simulators located in the proposed heliostat fields and were removed periodically. The spectral hemispherical and diffuse reflectances of these coupons were measured. Representative samples were analyzed for the chemical composition of the dust particulates using SEM/EDX. Other samples were washed with a high pressure spray and recharacterized to determine the effects of the residual dust. Average specular reflectance losses over the entire test period (up to 504 days) were 6 to 12%, with a range of 1 to 30%. Specular reflectance losses varied widely from day to day depending on local weather conditions. The losses due to scattering were 2 to 5 times greater than the losses due to absorptance. The average degradation rate over the first thirty days was an order of magnitude larger than the average degradation rate over the entire sampling period. Specular reflectance loss rates averaged 0.5% per day and greater between periods of natural cleaning. The chemical composition of the dust on the mirrors was characteristic of the indigenous soil, with some samples also showing the presence of sulfur and chlorine, possibly from cooling tower drift.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- DOE Contract Number:
- AC06-76RL01830
- OSTI ID:
- 5351626
- Report Number(s):
- PNL-4073; ON: DE82007116
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
MIRRORS
CONTAMINATION
WEATHERING
AEROSOLS
CHEMICAL COMPOSITION
CHLORINE
DUSTS
HELIOSTATS
KANSAS
LOSSES
MATERIALS TESTING
OKLAHOMA
REFLECTIVITY
SOILS
SOLAR TRACKING
SPECTRAL REFLECTANCE
SULFUR
WASHING
CLEANING
COLLOIDS
DISPERSIONS
ELEMENTS
EQUIPMENT
FEDERAL REGION VI
FEDERAL REGION VII
HALOGENS
NONMETALS
NORTH AMERICA
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
SOLAR EQUIPMENT
SOLS
SURFACE PROPERTIES
TESTING
USA
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