How to calculate Power from bifacial_radiance?

[yjkm]

Hello,

I have a quick question - how can one convert the irradiance values we get from bifacial_radiance into PV power? From the papers that I have read, it seems that the bifacial gain is only shown - is there a reason behind it?

I am aware that there is a Tutorial (number 8 I think), showing us mismatch losses but I cannot seem to find somewhere about power. What I normally do is Irradiance x Module Area x module efficiency

However, I think this is too vague as it is assuming things in STC and no reflectance + other type of losses.

Thank you in advance :-)

[kush987]

hey, yjkm i need some to understand the bifacial simultation. if u have some time can u explain me. if yes then ping me

[yjkm]

Hi @kush987, do you mean by the parameters? I do not think it would matter, I am finding it difficult to convert the irradiance values that I get into power or energy yield

[kush987]

values that I get into power or energy yield

Actually how to add the mirror reflector in the simulation for getting more energy values

[yjkm]

@kush987, I am not quite sure - perhaps find an albedo value for a mirror and add it in the simulation? Sorry, I am not that sure to assist you with mirror reflectors.

[kush987]

Thank u very much to show you interest on this question

[yjkm]

No worries - happy to help!

If you, or anyone, can help me with how to convert irradiance values to power or energy yield; I will be highly grateful!

[ECSape]

Hi yjkm, if you modify the code provided in the tutorial 8 and feed the hourly irradiance results, it should produce a mismatch result.csv file. I believe that the second column 'Pavg' is the power output you need.

[ECSape]

However I haven't found the proper way to set the module efficiency and other parameters in the tutorial and the related paper. I hope that helps.

[yjkm]

Hi @ECSape, could you show me the altered (modified) code? Also, how was the AVG Power calculated?

[ECSape]

If you are using gui, just open up a new python file in spyder or other editors you like and run these code provided in tutorial 8 after the gui gave all the irradiance results.

testfolder = r'C:\Users\HaoxiangZhang\OneDrive - University of Southampton\Year 3\Year 3 Project\SimulationScene\power_mismatch_test\results' resultfolder = os.path.join(testfolder, 'results') #name of the power and mismatch output file here writefiletitle = "any_name_you_like.csv"

portraitorlandscape='portrait' # Options are 'portrait' or 'landscape' bififactor=0.9 # Bifaciality factor DOES matter now, as the rear irradiance values will be multiplied by this factor. numcells=72 # Options are 72 or 96 at the moment. downsamplingmethod = 'byCenter' # Options are 'byCenter' or 'byAverage'. bifacial_radiance.mismatch.analysisIrradianceandPowerMismatch(testfolder=resultfolder, writefiletitle=writefiletitle, portraitorlandscape=portraitorlandscape, bififactor=bififactor, numcells=numcells)

[ECSape]

[shirubana]

Hi,

While I suggest the above approach to calculate Mismatch losses, @ECSape approach is not easy to modify for module parameters (they can be set though). What I would suggest though is using :py:class:~bifacial_radiance.performance.calculatePerformance module that calls PVLib, and does the power calculation knowing the values.

Tips -If you want to include AOI losses, you can set up Glass = True. -Calculate an average irradiance (always clean up your values in bifacial_radiance in case they are not hitting the module for 'special' geometries (2-up+ collectors, cell level modules, etc); -Use the calculatePerformance to know the power output; this model also calculates module temperature if you know wind speed and ambient temperature -Adjust your final power results (hourly) for electrical mismatch loss by using the calculated irradiances standard deviation and the equation provided in https://onlinelibrary.wiley.com/doi/epdf/10.1002/pip.3259

I now realize that we did the release without including any tutorial of that module, but I have some available so I'll try to upload today.

[yjkm]

Hello,

Thank you for that - I guess I will wait for the tutorial to be up before I ask any more questions :D

[shirubana]

Here is an example using trackerdict . It's for the development version atm.

https://github.com/NREL/bifacial_radiance/blob/development/docs/tutorials/21%20-%20Example%20Simulation%20-%20Modeling%20Module%20Performance%2C%20an%20End%20to%20End%20Simulation.ipynb