Multiple Maximum Power Points

[sirihar]

Hi,

how does PVsyst (version 6.20) handle the fact that not all inverters are able to distinct between local and global MPPs?

For exampel: OptiTrac Global peak is a MPPT/algorith implemented in new inverters from SMA. Older ones, like Sunny Mini Central 5000A, does not have this function, instead it uses a conventional MPPT which cannot "see" whether a MPP is the true (global) MPP or a local one?

Operation at a local MPP will decrease the power outout from the potential output. But I am not sure how likely it is that an inverter actually will operate the system at a local MPP. It seems to me that PVsyst don't consider the issue - am I right?

Best regards,

Siri

[André Mermoud]

In the "Module Layout" calculation, PVsyst always takes the best MPP point indeed.

I don't see how to do differently: how to decide which maximum is really taken by the inverter ?

By the way this represents a very low energy uncertainty:

- the shading situations with 2 MPPt are not very significant: they only concerns the situation when the diffuse component is higher than the beam component, due to particular shading dispositions.

- for usual systems, the full electrical shadings loss (module layout calculation) is less than a very few percents during the year. The additional loss would be a fraction of this loss.

- the power difference between both points is not necessarily very high.