Unavailability loss

It is sometimes useful to anticipate system failures or maintenance stops in production forecasts.

You can define system unavailability as a time fraction (or a number of days). During these failure periods, the system is treated as inactive (OFF) in the simulation.

You can define specific unavailability periods for the system. Since this is typically unpredictable, PVsyst can also randomly generate these periods (up to 5 periods of any duration throughout the year).

The actual energy loss naturally depends on the season, time of day, and weather conditions during the unavailability periods. Therefore, the energy loss calculated by the simulation will not match the specified unavailability time.

Therefore the unavailability loss has only a statistical meaning.

NB: Due to its statistical nature, it is currently not possible to specify a predefined annual value for this loss.

You can achieve this by manually adjusting the periods through trial and error.