Hayes Time-Dependent Module Temperature Model should be added to temperature API.

Description A paper in JPV written by William Hayes in 2014 proposed a time-dependent module temperature model for fixed tilt utility-scale systems. (If anyone wants a copy of the paper, let me know). It’s main strengths are that it can model temperature at sub-hourly intervals because if factors in the time dependency of module temperature on its heat capacity. The paper claims higher accuracy than other models.

Proposed Solution

• This would be added as a function to the API, as pvlib.temperature.hayes. The goal is to translate the paper into a function.
• Unit tests would be fairly straightforward. Inputs/expected outputs & any potential failure modes
• Validate against other models, or if there happens to be any available MST data.

Potential Obstacles

• As far as I can tell, there isn’t anything in the paper that describes what initial condition to use. Each temperature is calculated based on the previous temperature in this model: so, what would be the initial module temperature?
• Some concern over validation. I don’t have access to the data used to validate this model.

Additional Notes I have started to prototype the API function for this and have discussed this feature with @wholmgren

[wholmgren]

Convention is for users to do that kind of prep. Keeps functions simple and maximizes user flexibility. If it were intimately tied to the model then we’d include it in the function, but I doubt that’s the case here.

[cwhanse]

I think I might start with the simplified approach and see how well it performs for now.

Hayes’ paper isn’t specific whether horizon shading etc. is considered, so I don’t see that using the simple VF expressions is a contradiction. OK for v1 of this to use those, IMO, and later, we can wire in more involved VFs which would also expand the parameter list e.g. to include ground coverage ratio.