CyL-GHI: Global Horizontal Irradiance Dataset Containing 18 Years of Refined Data at 30-Min Granularity from 37 Stations Located in Castile and León (Spain). - Llinet Benavides Cesar; Miguel-Ángel Manso-Callejo; Calimanut-Ionut Cira; Ramón Alcarria (Data, 2023)