I recently started using ladybug for radiation analysis and had wanted to test it on my building. However when doing it, the output of the values became messed up as seen below:
Your script works, nothing wrong with that. If you draw a simple geometry, e.g. a box, it works just fine.
There is something wrong with your geometry, that is imported from Revit. I don’t know what. Perhaps a bug, that should be posted with a rhinoinsiderevit tag so that it is noted by the relevant powers.
Perhaps you should try to not run the analysis on that surface, but a layer from it. Or drawing a simpler geometry.
But please note that your gridsize is 5 km, and should probably be closer to 5-10 m.