Wind erosion compromises the continued energy performance of solar energy systems. In this work, we demonstrate the metrological capability of LWIR-VOx thermal cameras to quantify the severity of erosion under laboratory conditions. The apparent emissivity indicator is shown to be sensitive to induced surface degradation and the correlation between apparent emissivity and visible transmittance of glass is established. These results open the possibility of a 2D mapping in apparent emissivity exploiting the capabilities of infrared imaging in order to locate the eroded areas and to quantify their severity.