(left) Cross-section of the soil irradiance using the monofacial module for two repetitive units of the east-west solar park. The dashed line indicates 100% of the annual GHI. The coloured zones represent ranges of the open field irradiance as explained in the main text. Red is <10%, orange is 10-15%, yellow is 15-40% and green is >40%. (right) Rank ordered curve for 100 points, corresponding to one repeated unit of the cross-section (see text for clarification of Rank). The corresponding curve to assess the soil irradiance test criteria is given by the grey line.