@chris Thank you for your reply. I’m fairly certain that this is a mapping issue and not the inherent variability of stochastic simulations. I’ve run these simulations many times using the two different methods and each time I come up with the same results (within 0.004%). I looked at the grids, as you suggested, but the input grids and the output grids are in the same order.
I also tried using higher-quality Radiance parameters but that also had no effect on the results.
I’m attaching the gh file. I’d appreciate it if you could let me know if I’ve done something wrong or if the mapping is a bug.
annual irradiance grid mapping bug.gh (92.7 KB)
Thank you!