steve ransome

Results 2 issues of steve ransome

- [x] Closes #925 - [x] I am familiar with the [contributing guidelines](https://pvlib-python.readthedocs.io/en/latest/contributing.html) - [x] Tests added - [ ] Updates entries to [`docs/sphinx/source/api.rst`](https://github.com/pvlib/pvlib-python/blob/master/docs/sphinx/source/api.rst) for API changes. - [ ]...

enhancement

I'll be adding the Loss Factors Models and Mechanistic Performance Models to PVLIB, . See http://www.steveransome.com/PUBS/1906_PVSC46_Chicago_Ransome.pdf for more details on what they do I hope it should be ready by...

enhancement