How to Add or create a mirror reflector according to the panel position to calculate the Front and back side radiance??

[kush987]

I need to add a new mirror reflector object to calculate the radiance

[shirubana]

Hi, can you provide an image or drawing of what you are envisioning so I can make a tutorial?

[kush987]

Like this image

On Mon, 7 Feb, 2022, 8:36 pm Silvana Ovaitt, @.***> wrote:

Hi, can you provide an image of what you are envisioning so I can make a tutorial?

— Reply to this email directly, view it on GitHub https://github.com/NREL/bifacial_radiance/issues/372#issuecomment-1031566729, or unsubscribe https://github.com/notifications/unsubscribe-auth/AXLHJZSVA4LTDQBYR3DKFUDUZ7NWJANCNFSM5NWSA3NQ . Triage notifications on the go with GitHub Mobile for iOS https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675 or Android https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub.

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[shirubana]

Image didn't came through, you might need to paste into the issue directly through Github and not by mail (which seems to be the method)

https://github.com/NREL/bifacial_radiance/issues/372#issuecomment-1031566729

[kush987]

Like this image Is it possible to integrate

[kush987]

• I need to calculate the rear panel radiation
• mirror could be curve or flat

[yjkm]

A "perfect" mirror has an albedo of 1, so I would assume what you can do is set the albedo = 1 in the code or in the GUI - that will mean you will get a flat mirror. However, if that were to be the path that you go through, that would mean the "pitch" (row-to-row spacing) would all be covered by a mirror - which doesn't seem feasible in practice.

[kush987]

How does it work in the case of a curved mirror ??

[shirubana]

@yjkm I just added a tutorial example (Tutorial 22) on development branch showing how to do your first image, I hope it helps.

@kush987 Regarding curved mirror, you can import a CAD, or look into radiance code itself it does have some 'genrev' surfaces. However, using curved surfaces in the raytrace is not ideal as it tesellates the curvature, so you end up with WAY TOO MANY surfaces which slows down, and you might get some weird artifcats. I'd suggest approximating the curved surface by a good amount of flat surfaces placed properly to simulate the curve. More on this forum. https://discourse.radiance-online.org/t/curved-mirror-surfaces/685

[kush987]

Member

Can we reposition the mirror as our requirement

[shirubana]

Yes. See the tutorial and calculate the position on where you want them.

[kush987]

• I need to calculate the rear panel radiation
• mirror could be curve or flat

For this image we can follow the tutorial_22 ????

[kush987]

Your simulation will be stored in D:\new Bifacial\bifacial_radiance\bifacial_radiance\TEMP path = D:\new Bifacial\bifacial_radiance\bifacial_radiance\TEMP Loading albedo, 1 value(s), 0.200 avg 1 nonzero albedo values. Getting weather file: USA_VA_Richmond.724010_TMY2.epw ... OK! 8760 line in WeatherFile. Assuming this is a standard hourly WeatherFile for the year for purposes of saving Gencumulativesky temporary weather files in EPW folder. Coercing year to 2021 Saving file EPWs\metdata_temp.csv, # points: 8760 Calculating Sun position for Metdata that is right-labeled with a delta of -30 mins. i.e. 12 is 11:30 sunpos

Module Name: test-module Module test-module updated in module.json Pre-existing .rad file objects\test-module.rad will be overwritten

Created tutorial_22.oct Linescan in process: tutorial_22_Front Linescan in process: tutorial_22_Back Saved: results\irr_tutorial_22.csv Result without mirror: <module 'unittest.result' from 'C:\Users\kushal.kumar\.conda\envs\bifi1\lib\unittest\result.py'> Material exists, overwriting...

Added material testmirror to file ground.rad

Module Name: test-mirror Module test-mirror updated in module.json Pre-existing .rad file objects\test-mirror.rad will be overwritten

Created tutorial_22.oct Linescan in process: tutorial_22_withMirror_Front message: rtrace: fatal - bad number of arguments for mirror "testmirror" Linescan in process: tutorial_22_withMirror_Back message: rtrace: fatal - bad number of arguments for mirror "testmirror"

(bifi1) D:\new Bifacial\bifacial_radiance\bifacial_radiance>python mirroring.py
Your simulation will be stored in D:\new Bifacial\bifacial_radiance\bifacial_radiance\TEMP path = D:\new Bifacial\bifacial_radiance\bifacial_radiance\TEMP Loading albedo, 1 value(s), 0.200 avg 1 nonzero albedo values. Getting weather file: USA_VA_Richmond.724010_TMY2.epw ... OK! 8760 line in WeatherFile. Assuming this is a standard hourly WeatherFile for the year for purposes of saving Gencumulativesky temporary weather files in EPW folder. Coercing year to 2021 Saving file EPWs\metdata_temp.csv, # points: 8760 Calculating Sun position for Metdata that is right-labeled with a delta of -30 mins. i.e. 12 is 11:30 sunpos

Module Name: test-module Module test-module updated in module.json Pre-existing .rad file objects\test-module.rad will be overwritten

Created tutorial_22.oct Linescan in process: tutorial_22_Front Linescan in process: tutorial_22_Back Saved: results\irr_tutorial_22.csv Result without mirror: <module 'unittest.result' from 'C:\Users\kushal.kumar\.conda\envs\bifi1\lib\unittest\result.py'> Material exists, overwriting...

Added material testmirror to file ground.rad

Module Name: test-mirror Module test-mirror updated in module.json Pre-existing .rad file objects\test-mirror.rad will be overwritten

Created tutorial_22.oct Linescan in process: tutorial_22_withMirror_Front message: rtrace: fatal - bad number of arguments for mirror "testmirror" Linescan in process: tutorial_22_withMirror_Back message: rtrace: fatal - bad number of arguments for mirror "testmirror" Traceback (most recent call last): File "D:\new Bifacial\bifacial_radiance\bifacial_radiance\mirroring.py", line 146, in withMirror = bifacial_radiance.load.read1Result('results\irr_tutorial_22_withMirror.csv') File "d:\new bifacial\bifacial_radiance\bifacial_radiance\load.py", line 164, in read1Result resultsDF = pd.read_csv(selectfile) File "C:\Users\kushal.kumar.conda\envs\bifi1\lib\site-packages\pandas\util_decorators.py", line 311, in wrapper return func(*args, **kwargs) File "C:\Users\kushal.kumar.conda\envs\bifi1\lib\site-packages\pandas\io\parsers\readers.py", line 680, in read_csv return _read(filepath_or_buffer, kwds) File "C:\Users\kushal.kumar.conda\envs\bifi1\lib\site-packages\pandas\io\parsers\readers.py", line 575, in _read parser = TextFileReader(filepath_or_buffer, **kwds) File "C:\Users\kushal.kumar.conda\envs\bifi1\lib\site-packages\pandas\io\parsers\readers.py", line 933, in init self._engine = self._make_engine(f, self.engine) File "C:\Users\kushal.kumar.conda\envs\bifi1\lib\site-packages\pandas\io\parsers\readers.py", line 1217, in _make_engine self.handles = get_handle( # type: ignore[call-overload] File "C:\Users\kushal.kumar.conda\envs\bifi1\lib\site-packages\pandas\io\common.py", line 789, in get_handle handle = open( FileNotFoundError: [Errno 2] No such file or directory: 'results\irr_tutorial_22_withMirror.csv' this error will come after running the "Mirror_and_Module.py" file

[shirubana]

I suspect you don't have the latest version of development that fixed a bug on how the material gets saved; I published this bug fix with the journal, and it changes the number of arguments for primitives (materials) of 'mirror' type to 3.

To confirm which version you are running ,pleas eprint

bifacial_radiance.version

It should be '0.4.0-dev2' or something like that.

[kush987]

I suspect you don't have the latest version of development that fixed a bug on how the material gets saved; I published this bug fix with the journal, and it changes the number of arguments for primitives (materials) of 'mirror' type to 3.

To confirm which version you are running ,pleas eprint

bifacial_radiance.version

It should be '0.4.0-dev2' or something like that.

I have a question so this mirror is working like a mirror reflector. Or not????

[shirubana]

Yes, it is; is there another option or what is the question? If you notice on the example I provided there is a very big increase from including the mirror on the simulation vs no mirror; that is the sanity check.

You will have to play with the coordinates to create the mirror in the position you want for your example.