Daily input output

[M0GLI]

What is the significance of Daily input output diagram of PVsyst?

[André Mermoud]

Each point of the graph represents the production of one day.

On the x-axis, you have the daily irradiation in the collector plane [kWh/m2/day]

On the y-axis, you have the system's production [kWh/day]

For Grid-connected systems, this is usually very linear (points below correspond to days with special losses like shadings or system unavailability). You have often a curvature in the upper part, corresponding to higher operating temperatures in summer.

For Stand-alone or pumping systems, it is much more instructive: a plateau indicates that the storage is full: if the plateau is low (begins very early), your storage (battery or water tank) is not sufficient: for many days the production is limited by the full filling of the storage. A well-sized storage will give a little plateau in the upper part of the graph.