Hello,

I had a problem today with the specific annual yield calculation. I planned twice a PV plant with different load profile, but the devices (Inverter, Modules, Batteries) remained unchanged. Surprisingly the specific annual yield changed. Do you have any explanation why the specific annual yield is function of - or at least is influenced by - consumption?

Thanks in advance
Kamal

Hi Kamal,

thank you for your question. In general the specific yield is not influenced by the consumption or the battery system, as long as it is AC coupled. That means that electric appliances and the battery system etc are connected on the AC side of the PV inverter. This is the case for most of the battery systems. But there are systems that are coupled on the DC side of the PV inverter, we call that DC generator or DC intermediate coupling. Refer to these explanations here:

https://help.valentin-software.com/pvsol/2019/calculation/battery-systems/#type-of-coupling

In the case of DC couplig the battery system and the consumers influence the AC output of the PV inverter, and so they influence the specific yield. On the one hand this is obvious, on the other hand it might seem a bit confusing, as you pointed out correctly. We are aware of this and we think of making it more clear in the results where the differences in yield come from.

Hope that helps in the meanwhile, kind regards,

Martin

Hey, I have encountered similar situation when using two Solaredge inverters in one case and only one Solaredge inverter in the other case. The inverter efficiency in both the cases is more or less the same. I convinced myself saying that with change in load profile on the inverter, the point of operation on the inverter efficiency curve changes and hence change in specific annual yield. could this also be one of the potential reasons for the change in yield???

Hello Vishnu,

yes exactly. If the efficiency curve of used inverters is different and they are configured differently, then the specific yield is different.

Kind regards,

Marcel