Solar attenuation measurement system based on digital cameras
The atmospheric attenuation of solar radiation reflected by heliostats to the receiver is recognized as an important cause of energy loss in plants increasingly large solar towers. During the design of these plants, it is essential to have attenuation maps similar to those of solar resources. Unfortunately, the truth is that until now there was no reliable measurement method for solar attenuation and, at present, these plants are designed, built and operated without knowing this local parameter. The objective of this innovative measurement system developed by the Almeria Solar Platform (PSA-CIEMAT) is to take simultaneous images of the same objective at very different distances using two identical optical systems with digital cameras (from Hamamatsu), suitable lenses and filters.
Having Lambertian targets is important for this measurement system, since the position of the cameras and the angles relative to the objective can never be known with certainty over such great distances.
Hamamatsu has published an application note regarding the system marketed by BCB on Applications of high resolution digital cameras in solar tower plants. A novel measurement method based on digital images and Lambertian target. And this news has also been echoed on the CIEMAT website.