pvlib python is a community-developed toolbox of functions and classes for simulating photovoltaic system performance, with the stated aim of providing open, reliable, interoperable and benchmark implementations of PV system models. The stable release is version 0.15.2.
It began in 2013 as a Python translation of Sandia National Laboratories’ MATLAB PVLIB toolbox and is now maintained by a core group of PV modelers with contributions from more than a hundred people. It is a NumFOCUS Affiliated Project under a BSD 3-clause license, with support from the Department of Energy, NumFOCUS, Google Summer of Code, universities and companies.
How it gets used on a real project
Once you are running the same production calculation more than a handful of times, or need to do something a commercial tool will not, pvlib is the step past the graphical interface. Sweeping hundreds of layout configurations, batch-processing sites, or building a repeatable analysis pipeline are all straightforward in pvlib and painful anywhere else.
It is equally valuable as documentation. The models are implemented in readable code with citations to the literature, so when you need to know exactly what a transposition or temperature model does, you can read it rather than infer it from a vendor’s help file.