Due to a home renovation I need to re-arrange my panels on a Sunsynk 8kw inverter. I can get 9 520W Jinko on the new north facing roof on one string. The other string of 8 320W Canadian Solar can either be West or East facing.

Can I split this string (half East, half West) to maximize the hours of daylight on the panels or will this be counter productive?

Suggestions please

If 4 of the Canadian Solar add up to a Voltage that would function (high enough for the MPPT to be happy), I;d say have a 4S string to the east and a 2nd 4S string to the west and these in parallel on the 2nd MPPT of the inverter...

Thanks Meerkat, that makes sense

On 2022/08/23 at 10:50 PM, Madscot said:

Can I split this string (half East, half West) to maximize the hours of daylight on the panels or will this be counter productive?

I found my string towards the evening sun to produce relatively little - and would not do it again. I would rather place all panels into your morning sun.

Your MPPT needs 150V to start up - and I would be concerned that with 4 panels you'll spend too much time below that and loose out on production

20 minutes ago, wolfandy said:

I found my string towards the evening sun to produce relatively little - and would not do it again. I would rather place all panels into your morning sun.

Your MPPT needs 150V to start up - and I would be concerned that with 4 panels you'll spend too much time below that and loose out on production

Did you use a single string for the East/West panels.

5 minutes ago, Scorp007 said:

Did you use a single string for the East/West panels.

No - separate strings

When I did my system upgrade, I split what used to be my main string of 12x 380W panels and put each 6x East and West on separate MPPTs

Here you can see the performance of both string in comparison (yellow line in each chart). Just please pay attention to the different scales in the graph (don't know how to set both to the same scale in SolarAssistant)

MPPT 1 is morning sun, MPPT 2 is evening sun - both charts from today

Thanks Wolfandy. Could it be that the evening generation is lower due to batteries already charged so less demand?

 

17 hours ago, wolfandy said:

both charts from today

looks like it was cloudy... if that's the case the graph has little real value... panels to the west may be of not that big a value to most (that still hang off commercial power) here, it does produce an is used I'll attach yesterday's PV1/PV2/Combined graph... PV1 is fixed @355° and PV2 has an axis app. N-S and will be looking east and be turned to be flat on their backs by 12:15 or so and to the west after around 14:00. (I turned them around 10:30-odd to be app. 20° east of being flat on their backs, again at app. 12:15 flat on their backs and a bit late, by about 14:23 to the west, app. 45° from being flat on their backs. I didn't turn them to the east the previous night and got out late, only turned them at 07:35 to the east, from the previous afternoons west. Attached the graph for this morning, by 07:15 PV2 starts producing... which should have been the previous graphs' scenario as well.) PV1=9 x 280W JA, PV2=8 x 280W JA

 

2 hours ago, Kalahari Meerkat said:

looks like it was cloudy... if that's the case the graph has little real value... panels to the west may be of not that big a value to most (that still hang off commercial power) here, it does produce an is used I'll attach yesterday's PV1/PV2/Combined graph... PV1 is fixed @355° and PV2 has an axis app. N-S and will be looking east and be turned to be flat on their backs by 12:15 or so and to the west after around 14:00. (I turned them around 10:30-odd to be app. 20° east of being flat on their backs, again at app. 12:15 flat on their backs and a bit late, by about 14:23 to the west, app. 45° from being flat on their backs. I didn't turn them to the east the previous night and got out late, only turned them at 07:35 to the east, from the previous afternoons west. Attached the graph for this morning, by 07:15 PV2 starts producing... which should have been the previous graphs' scenario as well.) PV1=9 x 280W JA, PV2=8 x 280W JA

 

Thanks a lot for sugaring the details. Very interesting to look at the outputs and the turning of panels.

The East/West is something I cannot try at my place so I stick to North.

 

Appreciate all the good advice given, thanks. Here is some feedback:

My goal was to limit what i take from Eskom and to provide backup power for loadshedding. 

I opted for 8  x 470W on the (new) north facing roof on one string.

They were the largest of my stock and nine would have taken the Voc max too close to the MPPT Max input for my liking.

The others were split with 8 x 330W in a N/E orientation and 8 x 300W facing NNW. these two strings were paralleled on the 2nd MPPT.

Results were quite good. The NE facing picks up the sun first and starts to supply/charge the batteries.

The North facing provides supply for the house and bulk charge for the batteries.

Those NNW provide power as the sun goes down delaying the onset of battery discharging.

 

I'm not quite off grid but my metered consumption is about 20% of what is was pre-solar.

The main DB is configured with most loads going to the inverter with Oven, dishwasher & microwave remaining on the metered supply. I will probably change this.

Peak solar supply has been 6.8kW so far. In the graph blue is the North facing  and green the East/West array.

Thanks again to those that helped me here

On 2022/08/29 at 9:20 AM, Kalahari Meerkat said:

looks like it was cloudy...

You can't win.

I have 6 panels facing N and 6 facing E. I curse whenever we have overcast mornings and then bright afternoons because of all that power I could be harvesting in the afternoon.

But then it can be the other way around: the morning is clear, my batteries are charged by 10:30 ish, and then it gets overcast in the afternoon. But by then I need just enough PV to keep things ticking over.

Interestingly, I find my E facing panels making a contribution until 3 in the afternoon in the summer. By now the N facing string is dominant, but the E facing string is still delivering a useful amount. So the panels seem to have quite a broad range of angles of incidence in which they will generate power.

On 2022/08/23 at 10:50 PM, Madscot said:

Due to a home renovation I need to re-arrange my panels on a Sunsynk 8kw inverter. I can get 9 520W Jinko on the new north facing roof on one string. The other string of 8 320W Canadian Solar can either be West or East facing.

Can I split this string (half East, half West) to maximize the hours of daylight on the panels or will this be counter productive?

Suggestions please

There are some creative ways to connect panels - see
https://powerforum.co.za/topic/16246-which-solar-panels-combo-is-best-for-my-sunsynk-8kw-inverter/#comment-147537

 

Thanks for the feedback. I am quite happy with the configuration and the solar output for now. Will look at the other creative connections later.

Correction: In my p0st above I said 8 panels were NNW, the should have been WNW