Hi Paul,
Thank you!
Just thought I would let you know that I was able to work around this by generating a layout in SolarPILOT and exporting it to SAM. The annual simulations seem to then work.
I do seem to be having a slight issue with SolarPILOT however, where, when I run a full annual simulation to generate a heliostat field, the green progress bar goes to completion and the entire 8760 hours seem to have run, but the programme freezes anjd crashes each time before any sort of layout appears. I have deleted and reinstalled the software to no avail. I'm not sure if you cover SolarPILOT in these forums?
Thanks,
Harry