[M-ZZ39] Scientific, technical, and educational aspects of renewable energy

[MZZ39-P02] Cloud-base height derived from all-sky images: methods, validations, and applications on solar irradiance estimation

Hung-Chun Hou¹, Chen-Jeih Pan², Hsin-Chih Lai^3,4, *Shih-Sian Yang³ (1.Tohoku University, 2.Department of Space Science and Engineering, National Central University, Taiwan, 3.Environmental Research and Information Center, Chang Jung Christian University, Taiwan, 4.Department of Green Energy and Environmental Resources, Chang Jung Christian University, Taiwan)

Keywords:All-sky imager, Cloud-base height, Cloud cover, Solar power

An all-sky imager (ASI) observes the sky at its location. The cloud cover and solar irradiance derived from images present the information only at the ASI station. Within cloud-base height (CBH), an all-sky fisheye image (clouds taken from the ground) can be converted to a cloud map (as seen from the sky) in the geographic coordinate system, showing the spatial distribution of clouds beyond the ASI station and maximizing the observational value an ASI may have. Therefore, we have designed two and one methods using the images recorded by dual and single ASI, respectively. The results of each method are compared with several kinds of external CBH data, including ceilometer, radiosonde, and satellite observations. We will also introduce our three campaigns for CBH measuring. Finally, we conclude that the single ASI method seems to be the most promising one to be employed to derive CBH using the ASI network in Taiwan.