Create FAQ page in sphinx User Guide

[kandersolar]

• [x] Closes #1546
• [x] I am familiar with the contributing guidelines
• ~[ ] Tests added~
• ~[ ] Updates entries in docs/sphinx/source/reference for API changes.~
• [x] Adds description and name entries in the appropriate "what's new" file in docs/sphinx/source/whatsnew for all changes. Includes link to the GitHub Issue with :issue:`num` or this Pull Request with :pull:`num`. Includes contributor name and/or GitHub username (link with :ghuser:`user`).
• ~[ ] New code is fully documented. Includes numpydoc compliant docstrings, examples, and comments where necessary.~
• [x] Pull request is nearly complete and ready for detailed review.
• [x] Maintainer: Appropriate GitHub Labels (including remote-data) and Milestone are assigned to the Pull Request and linked Issue.

Here's a first crack at an FAQ page. Additions and revisions are very welcome. I've marked it for 0.9.3 but also fine to push it to later.

Rendered page: https://pvlib-python--1549.org.readthedocs.build/en/1549/user_guide/faq.html

[AdamRJensen]

Hi @kanderso-nrel

pvlib sounds pretty cool! Is there anything I shouldn't use pvlib for or that it can't do? Financial calculations, uneven terrain?

[AdamRJensen]

Where can I get irradiance data for my simulation? pvlib has a module called iotools which has several functions for retrieving irradiance data as well as reading standard file formats such as EPW, TMY2, and TMY3. For free irradiance data, you may consider NREL's NSRDB which can be accessed using the (:func:pvlib.iotools.get_psm3 function and is available for North America. For Europe and Africa, you may consider looking into CAMS (:func:pvlib.iotools.get_cams). PVGIS (:func:pvlib.iotools.get_pvgis_hourly) is another option, which provides irradiance from several different databases with near global coverage. pvlib also has functions for accessing a plethora of ground-measured irradiance datasets, including the BSRN, SURFRAD, SRML, and NREL's MIDC.

[kandersolar]

pvlib sounds pretty cool!

Glad to hear you think so! I agree :)

Is there anything I shouldn't use pvlib for or that it can't do? Financial calculations, uneven terrain?

I'm a little hesitant to include a list of things that pvlib is unsuitable for. For one, that list is infinitely long. For another, what is unsuitable depends on the user -- for example I myself would surely turn to pvlib if I were tasked with modeling a system on uneven terrain, but I might not recommend others do the same. I did try to implicitly address the financial calculations point by specifying electrical performance in the "what is pvlib?" question.

On the other hand, "how do I model variable terrain in pvlib?" has been asked before, so maybe that should be an item on its own?

[kandersolar]

I have added a link to the README as @cwhanse suggested in https://github.com/pvlib/pvlib-python/issues/1546#issuecomment-1238636327.

Finding myself with no motivation to write an entry on variable terrain, I suggest we proceed with the current set of FAQ entries and expand the list in future PRs.