[M-AG32] Renewable Energy

[MAG32-P11] Cloud observation and solar irradiance estimation using all-sky imagers in Taiwan-Ⅲ: Assessment of solar resources

*Shih-Sian Yang¹, Hsin-Chih Lai^1,2, Chen-Jeih Pan³, YIWEN CHEN³, Hungchun Hou⁴ (1.Environmental Research and Information Center, Chang Jung Christian University, Taiwan, 2.Department of Green Energy and Environmental Resources, Chang Jung Christian University, Taiwan, 3.Department of Space Science and Engineering, National Central University, Taiwan, 4.Tohoku University, Japan)

Keywords:All-sky imager, Cloud cover, Cloud optical thickness, Solar irradiance, Solar power

This presentation is the follow-up to our former presentations at JpGU Meetings 2023 and 2024, focusing on the solar resource assessment as derived from all-sky images in Taiwan. The Taiwan Central Weather Administration established an all-sky imager (ASI) network in 2021, which contains 22 stations in Taiwan. More than 10 million images were taken by this ASI network, which provides high-temporal resolution cloud information during the daytime. In this study, all the images were analyzed using our COT recognition technique, and the solar irradiance at each station was thus derived from ASI images. The results were further compared with pyranometer data. Good consistency was found, though a systematic difference exists between these two datasets. Moreover, the ASI-derived solar irradiance was used to assess the solar resources in Taiwan. An annual variation of solar resources was found at all ASI stations; however, the annual variation is more evident in northern Taiwan than in southern Taiwan. On the other hand, solar irradiance is higher in northern Taiwan than in southern Taiwan during summer months, even if the solar zenith angle is higher in southern Taiwan than in northern Taiwan.