bifacial pv terms

[shirubana]

Hello,

Just learned of this effort and it makes me so happy it's happening! 👯

Can we add a list of bifacial terms to this? That would also mean adding clarification to terms like
poa, from:

poa_direct [W/m^2]: Direct/beam irradiation in plane.

to

poa_direct [W/m^2]: Direct/beam irradiation in plane. In case of bifacial systems, poa considers front and back irradiances.

We are in the middle of a IEA report on bifacial, and it has helped come up with the terms and synonyms as well as nuanced differences for many of these. I can gather them in the next weeks and do a PR if we want to add that section.

[toddkarin]

Sure, adding bifacial terms and clarifications is a great idea. Happy to accept a PR on this.

[shirubana]

Ok, this is my first attempt. I'll try to gather a bit more feedback before doing it a PR?

[cwhanse]

bifi I think we could use a few more letters here. Or develop analogs to bifacial_gain_irradiance for _isc etc. Is there a reason the IEC group prefers bifi?

Rather than poa_front, _rear and _total, would modifying poa_global with the suffixes work? I.e. poa_global_front, poa_global_rear and poa_global (for _total). I'm thinking down the line the performance model that converts irradiance to power is likely to use only poa_global, and the _front and _rear quantities (outputs from irradiance modeling) are inputs to a function that computes poa_global. That way we don't have two terms for the same quantity, e.g., poa_global for monofacial and poa_total for bifacial.

[toddkarin]

Thanks @shirubana for working on this!

I'd prefer bifaciality or bifaciality_factor instead of bifi.

pvlib uses max_angle instead of limitangle.

I'd prefer backtrack over backtracking

For the variables with overlap to the existing pvfactors_timeseries function, what about using the existing variables?