Ladybug_Photovoltaic surface & parallel computing

Hi there,

I have been using Ladybug tools to identify the building areas that receive high levels or solar radiation and then calculate the PV performance of those surfaces. I find the tools and grasshopper very useful, especially because by data are is shapefiles and grasshopper allows me to import and process them.

More specifically, I am using the Ladybug Radiation Analysis component to isolate a number of building surfaces that meet a radiation threshold and afterwards the Ladybug Photovoltaic Surface and the Sunpath Shading components to calculate the amount of electricity produced of the assumed PV panels installed on those surfaces. I am simulating is an urban area of 100m by 100m and a mesh resolution of 1m. I have a powerful computer but it probably takes a day to calculate process the calculation and sometimes it gets stuck.

The Radiation Analysis component has the option of parallel computing, which speeds up the process. However, I saw a reply from Mostapha (Using a computational cloud to run simulations) that Radiation Analysis can run only inside Grasshopper; hence not in a cloud virtual machine (???). The Photovoltaic Surface or the Sunpath Shading they don’t have the option of parallel computing. Looking at my computer performance, the memory usage is very high, almost 31/32 GB and the CPU usage low, around 20%.

Is there a way to run those tools in parallel and make the most out of my CPU? On top of that, is there a way to run them on a cloud-based virtual machine, using multiple cores and get faster results?

If that’s not an option, are there any other tools that you would suggest, that can perform parallel computing?

I came across this discussion:

I understand that this is daylight, running Radiance. My bonus question is, parallel computing is something that the core software (Radiance) might allow, compared to PVWatts that Photovoltaic surface uses?

Any piece of help would be appreciated. Thanks a lot!


Hi Maria,

The Honeybee “Grid Based Simulation” component has an option to run radiation calculations via Radiance using GencumulativeSky. Gencumulative sky has been used in the past to calculate PV potential. If you are running your calculations off of Ladybug/Grasshopper, this approach with Radiance will most likely be faster.
I think the numOfCPUs option in the Honeybee “Run Daylight Simulation” will let you run the simulation simultaneously on multiple processors on your desktop. Beyond that, running the simulation on a remote cluster a.k.a cloud-based virtual machine will require some custom scripting as we detailed in that paper.


Hi Sarith,

Thanks for coming back to me. I use the GenCumulativeSky and the Ladybug Radiation Analysis to identify the suitable building envelope surfaces for the installation of rooftop or BIPV. It is true that the last one has the option to run the simulation simultaneously on multiple processors on your desktop. I prefer the Ladybug tool case, compared to Honeybee as I don’t need to define construction materials and building thermal zones. I believe that the outcome is similar as both run radiation calculations via Radiance.
However, when it comes to the simulation of the actual PV output, things get slower. I use the Ladybug Photovoltaic Surface and the Ladybug Sunpath Shading and they don’t have the option of parallel computing. I am wondering how I can speedup that process or if there is an alternative faster process for the PV output calculations.
Thanks again for you assistance!


I have the same question

Hey there,

I’m having the same issue as described in here and would like to know if there are any improvements planned in the future regarding PV energy yield and performance. It’s a shame not being able to use the full potential of my PC :sweat_smile:

Thanks in advance!

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