V8.0.11 Bifacial w/ Fixed Tilt Plane, Flush to Roof mount via Polygonal Fields - Not compatible w/ bifacial 2D model

[mikemay]

Hello Team,

I am using V8.0.11  and trying to model Bifacial w/ Fixed Tilt Plane, Flush to Roof mount via Polygonal Fields - this is not compatible with bifacial 2D model - is this a bug or is there some way that I could model this irregular layout with bifacial (see snip of model)? 

I realize this flush to roof the bifacial factor will be very small, but the client is determined to confirm modeling this bifacial gain..

Any suggestions and thoughts are greatly appreciated, much thanks in advance!

 

ie would converting to a Rectangular PV Array and trying to line up/match this jagged flush roof layout (as much as possible) allow the bifacial 2D model - or something else be a workaround?

 

Thanks, Mike

[dtarin]

You can use draw a zone in the shape of the area with PV tables that will allow bifacial computation.

[mikemay]

Hi dtarin, thanks for the input.

 

I can make a zone in a similar shape as the polygonal field, but when defining the Zone's Field Properties, I can only do a singular rectangular array - are you suggesting that I would have a bunch of little zones where I would need to align / elevate and line up each one  in order to mimic the flush to roof mount shown above?

The other factor that might complicate this the client wishes to use SolarEdge for this layout - not sure if using the zones in this manner would not be advisable then - ie defining the Module Layout's strings per inverter?

Thanks again for the help and insight, much appreciated!

[dtarin]

I don't have any the details of this system and haven't modeled solar edge in a long time. However, with a zone you can auto set table to fill the zone, auto tilt to adapt to slope of roof, set table size to 1x1, and then use module layout for allocation (electrical loss). Keep in mind this is just for shading calculation, not power, so you don't need it perfect. As long as it is reasonably close to capturing the shading conditions it should be fine. 

You create a single zone, insert masks, auto fill the zone as shown. This will allow you to model bifaciality. 

Edited May 10 by dtarin

[mikemay]

dtarin,

Thanks for that suggestion, I have since updated the model using zones, selected auto tilt, adjusted the spacing between modules to 0.009m (0.375" for module to module gap. I found it easier to forgo the masks for most of the design and just deleted the modules away where necessary.

 

When leaving the shade scene I get the following error: PV field is confused with, or very close to the object.

I do not have other shading objects, the fields are all above 0.05m (so as not be be obstructing with the roof)

This was setup using auto fill with my spacing of 0.009m module to module gaps, but is this too small for PVsyst?

What options do I have so as not to give bad bifacial gain representation between the module gaps and such?

Thanks again for the help!

Kind Regards,

Mike

[dtarin]

Try updating this. 

[mikemay]

Hi dtarin,

 

I updated that but I still get this error: Thoughts? Can I send over the project file for your take on it?

 

 

[dtarin]

Select 'Disable field interpenetration check' from inside shading scene and see if that works 

[dtarin]

If it still doesn't work you can always model it as I have above 🙂 The gaps will not matter for bifacial calculations, they are not used. The user defines the transparency factor manually which takes into account gaps in structure, modules, etc. So I'd either model as I have or increase the gap in your method if the suggestion above does not work. 

Edited May 16 by dtarin