Electrical loss according to strings decreases with reduced inter-row spacing

[Katinka]

Hello forum,

I am still in the early stages of working with PVsyst, so I hope the following question is not too stupid.

I wonder why the electrical loss according to strings decreases with reduced inter-row spacing.

I have assumed that it increases analogously to the near shadings: irradiance loss with smaller inter-row spacing due to higher mutual shading?

I have examined three different variants:

1) pitch: 12.5 | limit profile angle: 17° | electrical loss acc. to strings: -1.93 %

2) pitch: 13.2 | limit profile angle: 15.5° | electrical loss acc. to strings: -2.09 %

3) pitch: 13.6 | limit profile angle: 14.8° | electrical loss acc. to strings: -2.12 %

Thank you in advance!

[dtarin]

What is the nature of your shade scene? Is there terrain and/or other shading objects? Are you modeling in unlimited sheds or with a 3d shade scene?

[Katinka]

Many thanks for your reply!

The terrain is flat and there is forest in the direct surroundings. The sheds have a distance of 30m to the trees in east, south and west direction and 20m to the trees in north direction to minimize shading losses.

I model with a 3D shade scene.

[dtarin]

That is interesting. Without knowing the details of the simulation (partition size, tree height and design, table dimensions/orientation, location,etc), I would say that it is likely that as the modules move in closer to one another, they experience a higher near shading beam loss, but no additional electrical string activation. Since the beam loss increases but there is no additional string activation, the string loss comes down since that additional area of the array is now a light loss rather than an electrical one.