Array of trackers 3D scene defining N-S & E-W slopes

[JamesLenton]

Hello,

We are trying to model single axis trackers on different slopes:

- from +5 to -5 degrees N-S

- from +5 to -5 degrees E-W

The 'axis tilt' value for trackers can be changed to model N-S slopes in an array of trackers in the 3D scene. However, when we do a message appears saying "tracker axis must be horizonal for PVsyst to model the bifacial gain". Is there no way around this currently?

Secondly, there doesn't seem to be a method of inputting a E-W (tracker to tracker) slope for the array of trackers. Please could you point me in the right direction if there is a way of doing this?

Kind regards,

James.

[Michele Oliosi]

Hi !

1. Indeed, currently the backside and reflected irradiance modeling is quite picky. The idea is that the geometry it assumes is that of trackers on flat ground. The discrepancy between 3D scene and backside irradiance model therefore leads to this message, to warn users of the possible inaccuracy. However, there is no alternative model, and the approximation of flat ground is not too bad if the slope is only 5°. In other words:
   • You can change an advanced parameter to ignore the axis tilt message: Home window > Settings > Edit advanced parameters:
     
2. I think a good way currently is to build fixed tilt structures first and then use the "transform to trackers" option:
   
   This will ensure that you can use the row-to-row slope options which are available for fixed tilt arrays (if I am not mistaken).

[JamesLenton]

Hi Michele,

Thank you for the response. The solutions for running the simulation with high tilted axis worked, as did making fixed tilt array first with E-W slope before transforming to trackers.

I suppose there will be inaccuracy in the bifacial modelling if we are using sloped trackers but PVsyst assumes a flat axis, no other way to solve that so no worries.

Best,

James.

[Michele Oliosi]

@JamesLenton indeed, and glad that it worked !