Split face east west array same mppt

[Dylan]

Hi,

I know its been asked more or less, but not entirely clear for me at least.

Can you you have two arrays one pointing east and other pointing west on the same mppt with out a complete failure of power production.

Will consist of 6 panels two strings (3 series) 

3 in series on west and 3 in series west, I understand the mpp will play with the voltage to get the best power and since the series strings do not go over the east west divide surely the mppt will give the best voltage to produce max power, and not be drawn too much down for array that is starting to shade.

Can only fit ~3/4 panels North, the idea is to maximise solar power for longest period of the day, and doing it this way would save 1 mppt at 4k and all the switches fuses and protection that comes with two strings 2k.

Looking at an overall installed cost of 100k excl certification and an extra 10 isn't nothing.

[Chris Hobson]

East West arrays is an idea from Germany where low monetary  returns on exported power increase the need for self-consumption. If you want to do it on the same MPPT there are some provisos.  Each array must be made up of the same number of identical (make and model) panels. The panels should be inclined 15° and the panels should face East - West. Under these circumstances you can get away with a single MPPT.

[Dylan]

25 minutes ago, Chris Hobson said:

East West arrays is an idea from Germany where low monetary  returns on exported power increase the need for self-consumption. If you want to do it on the same MPPT there are some provisos.  Each array must be made up of the same number of identical (make and model) panels. The panels should be inclined 15° and the panels should face East - West. Under these circumstances you can get away with a single MPPT.

Thanks Chis,

Whats the reason for 15deg limitation?

[Garthvs]

I'll be testing the East West split on a single MPPT in the next week or so and will give feedback.  I won't be using the 15° idea though as it doesn't really make sense to me other than from an optimisation perspective and I can't actually use 15° on the test roof.

[DeepBass9]

Just get another MPPT, they are cheap enough and you have some redundancy. I had a single MPPT which was damaged by lightning. I ran on a generator for a week while it was repaired. I since added another array with its own MPPT, so if I lose one MPPT or solar array, at least I will have one array up and working power.

Edited November 1, 2018 by DeepBass9

[phil.g00]

Some light reading on the topic:

https://www.energymatters.com.au/images/news/2013/east-west-solar-paper.pdf

[Dylan]

3 hours ago, phil.g00 said:

Some light reading on the topic:

https://www.energymatters.com.au/images/news/2013/east-west-solar-paper.pdf

Thanks Phil, that paints a pretty clear picture that at the very least it's possible and can be the optimum solution if done right.

[Chris Hobson]

7 hours ago, Dylan said:

Thanks Chis,

Whats the reason for 15deg limitation?

If you go to a greater inclination then in winter the sun is at a very oblique angle and production suffers.

[seant]

The install of the pannels on the east and west side can be raised off the roof in the north/south inclination  , it seems to work quite well