Something I’ve been working on for while is a program called solpy. solpy is is a python library to model solar system power performance similar to PVWatts or NREL’s System Advisor Model(SAM). This is primarily a research and analysis tool and there is no guarantee on the calculations. I initially started writing this while working in Bangladesh as a fairly crude calculator to go from a fisheye panorama to a csv of vectors for shading calculations, however there were several pieces that were added to make it a bit more useful. Daniel Thomas did work adding the Tang evacuated glass tube model. I cherry picked some pieces of Brandon Stafford’s pysolar for solar positioning although made some changes for my purposes. There is also a simple module for reading TMY3 data. This tool is rudimentary, but functional. It integrates with ipython for some command line functionality.