The value varies as per the season and time of the day. For example, value 1.000 represents 100% illumination or available radiation over the panels during any particular time of the day and .961 represent 96.1% illumination and so on. In ‘no shade’layout, the illumination over the panel is 100% most of the times except during morning and evening hours, when the height of the sun is 20° or below, with respect to site location, causes maximum shade.