# Bankability (P50,P90)

In the dialog *Bankability: Exceedance probability of the forecast yield* you can set the P value with which the profitability calculation is to be carried out.
The exceedance probability for the forecast yield is an important parameter for the **bancability** (financing protection) of large PV systems.
However, the information given relates **only to the concept of full feed-in**.
Unless otherwise specified, the P50 value is assumed by default in the revenue simulation.
For the economic efficiency calculation there is a choice between:

- P50 - PV*SOL® Default case
- P90 - 90 percent probability
- self-selected P-value

The **Overrun probability** indicates with which probability the simulated yield is reached or exceeded in practice. For example, an exceedance probability of 75% (P75) indicates that a certain simulated yield is exceeded in practice with a probability of 75%. The higher the probability, the lower the expected yield.

### P10/P90 Values from climate data

Normally the values for P10 and P90 are determined directly from the climate data and used in PV*SOL®.
This enables a realistic estimation of the probability of exceedance.
If the P10 and P90 values could not be determined from the climate data, for example because you imported your own climate data, you can also enter the parameters for determining the variability yourself:

- The parameter
**Variability of global radiation** must be set accordingly depending on the climate data set. A good estimate for Central Europe is about 4.5%, for more information see Accuracy of Meteonorm
The parameter **Insecurity of the simulation** can be used to cover further variabilities in the system

Both parameters are added quadratically to the total variability.

See also