Multi-orientation simulation

[Aparna]

Hi,

I tried simulating an E-W facing system in PVsyst 6.32. The simulations run were: 1) by conecting the E and W facing strings to the same inverter and 2) by connecting E and W facing strings to different inverters.

The output energy was same for both simulations. The mixed orientation mismatch loss for case 1 was only 0.1% and zero for case 2. The near shadings loss for case 1 was 0.3% and for case 2 it was 0.4%. All other losses remain the same.

How can the irradiance level loss vary when the layout remains the same?

What is the princpile behind the calculation of "mixed orientation mismatch loss"? The value of 0.1% for this loss appears to be too low.

Please clarify.

Thanks and regards,

Aparna

[André Mermoud]

I don't understand your statement. You don't mention that the irradiance level changes.

For the "Mixed orientation" calculation, the I/V curves of both orientations are mixed at each simulation step, and the resultant is used for the Pmpp determination. Mixing strings of different orientations usually doesn't produce much mismatch losses.