Su2rad Sketchup bifacial_radiance bifacial solar photovoltaic systems

I hope you all are doing well.

I am trying the bifacial radiance tool which is python wrapper to radiance developed by NREL that provides a set of functions and classes for simulating the performance of bifacial PV systems. I have gone through the examples provided in bifacial radiance library package and those are working as shown in the jupyter notebook files.

Presently, I am trying to include a Module Mounting structure (MMS) as per civil structure drawings in the bifacial radiance tool. As you know that creating objects in radiance is cumbersome hence I am trying external tool (e.g Sketch up) to create structure and read it using bifacial radiance.

For that, I have created an MMS drawing in SketchUp, and using Su2rad plugins I got the object rad file. However, I am facing some errors while adding exported Object rad file using makeCustomObject and appendtoScene.

kindly help me with how to read object created in other tool to radiance environment with Su2rad or by any other means.

Exported files from Su2rad

With Regards


The issues you are having are likely with Bifacial Radiance, not Radiance itself. I’d suggest checking out the documentation and tutorials at the Bifacial Radiance GitHub site: GitHub - NREL/bifacial_radiance: Toolkit for working with RADIANCE for the ray-trace modeling of Bifacial Photovoltaics

You could also state what exactly “I am facing some errors” means. My guess is that the exported SketchUp geometry rad file is just not quite dialed in yet for the appendtoScene function in BR. I know those guys from when I was at NREL myself, and they built a solid project around Radiance’s functionality, from what I recall. And they documented it pretty well. :wink:

Hi Rob,

Thanks for replying. :slight_smile:
I am working on bifacial radiance since a month and went through the tutorials too. Just for your information in Bifacial_radiance user has to write scripts (and I am sure it is core radiance script) in order to create objects. let’s say for a steel beam, or concrete pillar which are used in module supporting structure, user need to write down long radiance scripts. I want to avoid that by creating the supporting structure in Sketch up and used exported radiance folder (using Su2rad) in bifacial radiance. Then I am planning to use bifacial_radiance to measure the irradiance on solar PV module’s front and back surface. Though, I have some apprehension about proper alignment of PV modules with supporting structure.

I agreed that there is no issue with radiance. However, What I understand is that there should be some other way by which exported object can be read because bifacial_radiance also uses the core radiance scripting to create objects. I have seen documents where people has created object (e.g room) in sketch up and done the illumination study in radiance.

I am also unsure whether I have correctly exported radiance folder from sketchup using Su2rad. :frowning:

Please let me know whether I am able to convey my problem properly. if more information is still required I am happy to give. Kindly help me to resolve this problem.

Thanks in advance,

I have uploaded the image file for you to have look.

Again, the issue is that it appears you need to take your exported objects (from SketchUp) and import them some way with the tools available in the Bifacial Radiance project. The documentation there should tell you what functions are available, and the expected format of the geometry you wish to import.

The images don’t really tell us anything about what your issues are.

If you look at the tutorials for Bifacial Radiance, you will see how they expect you to add geometry. I was just peeking at this one: bifacial_radiance/5 - Medium Level Example - Bifacial Carports and Canopies + sampling across a module!.ipynb at main · NREL/bifacial_radiance · GitHub

If you look at how they add the columns (look at " 2. Adding the pillars" on the page linked above), they pass the scene descritpion as a text string to the customObject function:

text='! genbox black cuteBox 0.5 0.5 {} | xform -t -0.25 -0.25 0 -t {} {} 0'.format(z2nd, xleft, y2nd)

customObject = demo.makeCustomObject(name,text)

I think you need to take your Exported SketchUp geometry and make sure it’s properly formatted in “RadianceSpeak”, maybe using objview to do that, and then pass the contents of that export to Bifacial Radiance’s customObject function.