[Medium] What is the ideal tilt for a PV system?

[kandersolar]

The tilt of a PV system determines how well it is aligned with the sun throughout the year and is thus one of the core decisions affecting annual and seasonal production. A common rule of thumb used to be to set the array's tilt equal to the location's latitude, and although this practice is less common now, the insight that the ideal tilt depends on location is as relevant as ever.

For a given location and weather dataset, what is the tilt that maximizes annual POA irradiation?

There is more than one way to use pvlib to answer this question. Here are two possible approaches:

1. First, write code that can tell you the annual POA irradiation for a single tilt. Then, use a for-loop to iterate across candidate tilt angles and calculate the irradiation for each iteration. Finally, identify which tilt angle resulted in the maximum irradiation.
2. It is more complex to set up and use, but scipy's minimize_scalar function can be used solve this kind of optimization problem much more efficiently than a brute-force method.

Follow-up questions:

• How does the answer change if you maximize for just January irradiation instead of annual?
• How does the answer change if you want to minimize seasonality?
• Does the ideal tilt change if you use a different weather file (e.g. same location, different year?)
• Does the ideal tilt change if you use a different irradiance transposition model?