PV-System, Power as function of View & Time

The Solar PV-system comprises an array looking East (= +115 degrees from North), in combination with an array looking South (= +205 degrees from North).
A panel-array looking West on the tilted roof would be a fitting supplement for full, daylong coverage, but considering it's viewing direction of -65 or (+295) degrees from North (and the shade from western neighbour's roof) not a good investment.
This configuration provides PV-production as long as light is available.

The background for selecting this configuration?

Expected output-efficiency is related to the viewing direction, as indicated in this diagram, although consider also that output is variable with daytime & season.
According to this diagram for this latitude of +52 degrees the max. sun elevation has a variation between approx. 15 degrees on december 22 till approx. 62 degrees on june 22.
Mid-position is applicable in march and september.
[Other geo-locations have other results.]
Examples for PV-production on clear and sunny days around those dates.

Totaal = total, cumulative production this day from the whole PV-System (kWh)
Upper P / blue line = 1960Wp/Involar&SAJ-inverters, actual output (Wh) and achieved day-efficiency (kWh/kWp)
Lower P / red line = 2950Wp/STECA&Solis-inverters, actual output (Wh) and achieved day-effiency (kWh/kWp).
These 2 graphs have the following split-up of nominal panel-power over azimuth & elevation:

1960Wp = 1530Wp to East/ elevation 55 degrees + 430Wp to South/ elevation 15 degrees ~ 80% / 20%
2950Wp = 580Wp to East/ elevation 55 degrees + 2370Wp to South/ elevation average 15 degrees ~ 20% / 80%

This distribution and orientation shows in the graphs:

blue line has peak output at approx. 11:30 due to eastward orientation of it's panels
red line has peak output at approx. 13:00 due to southward orientation of it's panels
in midwinter the blue peak is higher than the red peak, because the low sun elevation better matches the higher panel elevation
contrary, in midsummer the red peak exceeds the blue peak, because high sun elevation well combines with low panel elevation
in spring and autumn the blue and red graphline are equivalent, mirrored.
the cumulation of blue line and red line always yields a broader (= less peaky) coverage than the individual segments

Due to installation history, with shifting of some panel-groups to get/test better positions, after several upgrades&modifications the 1960Wp-segment has a southward-component of approx. 20% and the 2950Wp-segment has an eastward-component of 20%.
Important is that the 20%-components have their own inverter, avoiding effects on the 80%-components!
Result: the peaking for each segment is not as clear as for segments which are 'purely' 100% aimed along a main line-of-sight: in this case, the 20%-component aimed in other direction slightly smooths the peak at the main line of sight, and generates a 'shoulder' at the offset line-of-sight.

Conclusion: looking South at one fixed elevation, with production peaking at noon is not the "one&only" solution to get year-round a good daily PV-production.
A combination of viewing directions (such as one segment Eastward and another segment Westward, or mixing segments aimed in various directions, with own inverter/segment) very often will provide a good (if not better) PV-production spread over the days and over seasons, due to a broader cumulative peak and the advantage of production running from sunrise till sunset.
The more uniform availablity of power over the day also means that consumption of PV-power more easily can be spread over the day.

September 1st, 2018 another 330Wp has been added to the group of 2950Wp => within that group 28% is looking eastward:
=> 2440Wp East-looking and 2800Wp is South-looking.
In 2021 the eastern neighbours changed their house (= extended roof) after which we try to compensate the resulting dip in morning PV-production by shifting some panels:
since September 09, 2021 600Wp has been shifted from looking south to looking east under +30 degrees elevation
=> 3040Wp East-looking & 2200Wp South-looking.
The tendency of the story above is still true, but over next year the figures/graphs will change ......

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