tracker algorithms

[wholmgren]

I'm in need of some single axis tracker algorithms that include back tracking. So:

1. Can anybody recommend a reference for a single axis tracker algorithm with back tracking?
2. Does anybody have a Python implementation of a tracker algorithm?
3. Should we add tracker algorithms to pvlib?

The best reference I have so far is a NREL tech report, but it doesn't include back tracking.

[wholmgren]

Turns out that pvlib matlab has a single axis tracker function pvl_singleaxis.m. Should definitely port this. It references

Lorenzo, E et al., 2011, "Tracking and back-tracking", Prog. in Photovoltaics: Research and Applications, v. 19, pp. 747-753. wiley.com

[wholmgren]

Where would this function live? In it's own module, maybe called tracking.py or trackers.py?

[robwandrews]

I think it warrants it's own module: tracking.py is my vote

[wholmgren]

PR #35 added a translation of pvlib matlab's pvl_singleaxis.m. Leaving this issue open for dual axis trackers.

[raphaelvarieras]

Hey all, I'm new to this repository. I did quite a bit of work on tracker algorithms when I was at Solaria/Nextracker and would be happy to be able to contribute. I created this framework in which all tracker systems are essentially just subsets of a hypothetical three-axis tracker with the three Euler angles.

[wholmgren]

Welcome. That sounds interesting. Do your algorithms include backtracking? Any IP/license issues?

[raphaelvarieras]

Yes, I implemented horizontal backtracking for all tracker azimuths if I remember well. I did not do it for tilted tracker, azimuth or dual axis. No IP/license issues that I know of but I will double-check.

[raphaelvarieras]

No IP/license issue confirmed. Should we have a quick call to talk about this?

[wholmgren]

Great. I would prefer to keep things as open on github as possible, though if necessary we can arrange a call if you email me at william.holmgren@gmail.com

Some questions to get started:

• Have you looked at the existing single axis tracker algorithm in tracking.py?
• Do you propose to replace that function entirely or add a new one?
• Have you tested the algorithms against each other?
• Would this be best implemented as a collection of functions or as a collection of classes with inheritance?

I think it would be nice to have some good documentation with diagrams/sketches to go along with this.