The reflectance of heliostat is a decisive factor for the efficiency of tower solar power station. The loss of specular reflectance due to dust has drawn more and more attentions. In this article

the causes of dust's influence on reflectivity are analyzed

the mirror sample installed on site is simulated

and the loss of reflectivity in natural dust and artificial dust is measured. On this basis

the effect of time and dust density on the reflectivity is investigated. The experimental results show that

natural ash accumulation for 30 days can cause a loss of reflectance of 25.88%

indicating the dust density has a greater influence on the reflectivity. If conditions permit

it is recommended that the dust be cleaned up in time to maintain high reflectivity to ensure power generation efficiency. This results provide a reference for power stations to develop a reasonable cleaning cycle.