Hi everyone

So for the past 6 months i have been using a SS5kw/5Kw Greenrich battery to run as a UPS for the house. 

Time has come to add panels to this... and chatting a company they advised that i can/should run 10 x 550kw panels... (and tbisnis the max recommended for the inverter)

Right now the ONLY 2 things that are not on the essential side is pool pump/geyser... everything else runs on the "UPS", we manage the loads during load shedding...but with panels that becomes easier.

My question is, i have searched forums and seen homes all with like 12 - 16panels on their roof with a 5kw system and here i am being quoted for 10panels, bearing in mind, I'll probably get another battery down the line, so i am hoping to future proof myself with panels.

Any help, advise would be appreciated.  Thanks.

As someone with 10 (lower-capacity 455W) panels, with the same Sunsynk inverter, what you've been quoted is a perfect start from my experience.

10 x 550w (I assume you meant 'w' rather than 'kw') panels will produce a peak of 5.5kW, which is a perfect match to the maximum the inverter can invert from DC to AC. Anything above that will either go to the battery (if it's not already full, to a maximum of a further 1kW or so); or will get completely lost.

Beyond this, overpanelling beyond this number only makes sense if you don't mind taking losses during mid-day (through clipping) and instead want to push up production earlier in the morning or later in the evening; or if you're looking to cater for days with cloudy weather.

I adjusted my geysers (both are fed solar through the non-essentials) to come on to follow the arc of my daily PV production (smaller geyser from 9:30AM, larger geyser from closer to midday) to follow the rise and fall of PV production over the course of the day. It's been incredible; production averages 25kwh to 30kwh per day in the summer here in JHB; my CoJ electricity bill has been slashed by more than half. I'm adding another inverter (and another 10 panels to match) to go after the remaining half of my bill.

Those running more than 10 panels on this inverter are mostly dealing with lower-capacity panels (say, 390w panels). For the 550w panels you describe, 10 is a perfect match to it's DC-AC inverting capabilities. Just ensure that your installers split the strings such that you stay in the correct voltage range for the MPPTs according to the specs of those panels.

 

You won't look back.

 

59 minutes ago, NadaCT said:

Hi everyone

So for the past 6 months i have been using a SS5kw/5Kw Greenrich battery to run as a UPS for the house. 

Time has come to add panels to this... and chatting a company they advised that i can/should run 10 x 550kw panels... (and tbisnis the max recommended for the inverter)

Right now the ONLY 2 things that are not on the essential side is pool pump/geyser... everything else runs on the "UPS", we manage the loads during load shedding...but with panels that becomes easier.

My question is, i have searched forums and seen homes all with like 12 - 16panels on their roof with a 5kw system and here i am being quoted for 10panels, bearing in mind, I'll probably get another battery down the line, so i am hoping to future proof myself with panels.

Any help, advise would be appreciated.  Thanks.

 

Edited February 5, 20242 yr by JayMardern

23 minutes ago, JayMardern said:

As someone with 10 (lower-capacity 455W) panels, with the same Sunsynk inverter, what you've been quoted is a perfect start from my experience.

10 x 550w (I assume you meant 'w' rather than 'kw') panels will produce a peak of 5.5kW, which is a perfect match to the maximum the inverter can invert from DC to AC. Anything above that will either go to the battery (if it's not already full, to a maximum of a further 1kW or so); or will get completely lost.

Beyond this, overpanelling beyond this number only makes sense if you don't mind taking losses during mid-day (through clipping) and instead want to push up production earlier in the morning or later in the evening; or if you're looking to cater for days with cloudy weather.

I adjusted my geysers (both are fed solar through the non-essentials) to come on to follow the arc of my daily PV production (smaller geyser from 9:30AM, larger geyser from closer to midday) to follow the rise and fall of PV production over the course of the day. It's been incredible; production averages 25kwh to 30kwh per day in the summer here in JHB; my CoJ electricity bill has been slashed by more than half. I'm adding another inverter (and another 10 panels to match) to go after the remaining half of my bill.

Those running more than 10 panels on this inverter are mostly dealing with lower-capacity panels (say, 390w panels). For the 550w panels you describe, 10 is a perfect match to it's DC-AC inverting capabilities. Just ensure that your installers split the strings such that you stay in the correct voltage range for the MPPTs according to the specs of those panels.

 

You won't look back.

 

 

Thanks for the feedback....we a relatively low usage household, peak winter is about 600kw per month... and like you said...i can add panels when i add another battery (next year worries).  Will post here with updates.

@NadaCT

Just take note if the installer want to use 10 x 550Wp solar panels they need to use both Mppt's in 5S1P configuration. 10S1P configuration on 1 MPPT could cause damage as the maximum Dc input voltage of 500v would be exceeded. The perfect fit for SS 5kw inverter would be 6 x550wp 6S1P on each Mppt totaling 12x550w= 6600w. 

Voc for 6×550wp =298v+8%=322v. Below Screen print for Jinko 550Wp panel.

5 minutes ago, TaliaB said:

@NadaCT

Just take note if the installer want to use 10 x 550Wp solar panels they need to use both Mppt's in 5S1P configuration. 10S1P configuration on 1 MPPT could cause damage as the maximum Dc input voltage of 500v would be exceeded. The perfect fit for SS 5kw inverter would be 6 x550wp 6S1P on each Mppt totaling 12x550w= 6600w. 

Voc for 6×550wp =298v+8%=322v. Below Screen print for Jinko 550Wp panel.

I ideally want 12 panels that way my system won't struggle in Winter... but I'll run this by them, alternatively i can always fit the other 2 panels at a later stage.

2 hours ago, NadaCT said:

I ideally want 12 panels that way my system won't struggle in Winter... but I'll run this by them, alternatively i can always fit the other 2 panels at a later stage.

Depending on the specs of the inverter Sunsynk do quote maximum panels to be from 6000-6500W for the 5.5KW. Refer to the sticker on the inverter. 

As @TaliaB indicated 12 is fine with 6 per MPPT. 

4 hours ago, NadaCT said:

I ideally want 12 panels that way my system won't struggle in Winter... but I'll run this by them, alternatively i can always fit the other 2 panels at a later stage.

Look at the spec of the panels, not just the number. I have 12, but they're 375 watts. 10 @ 455 gives you very slightly more than I have. 10 @ 555 significantly more. 

9 hours ago, NadaCT said:

I ideally want 12 panels that way my system won't struggle in Winter... but I'll run this by them, alternatively i can always fit the other 2 panels at a later stage.

Adding 2 panels later will cost you a lot more than just the price of the panels.

I am looking at doing 8x 550w Jinko's on 1 string, they face NE and the open circuit voltage will be 396.8v. I am in Durban and the coldest it gets here is 11 degrees so should be okay. If your temperatures goes close to 0 then you might need to look at 6 or max 7 panels. I currently have 4 x 450w panels on a micro inverter VOC is 49.1v and the maximum they get to is 42.3v and these are where the 8x 550w panels will go. I also think if you face them North you have to cut down on the number of panels.

18 hours ago, Scorp007 said:

Depending on the specs of the inverter Sunsynk do quote maximum panels to be from 6000-6500W for the 5.5KW. Refer to the sticker on the inverter. 

As @TaliaB indicated 12 is fine with 6 per MPPT. 

Specs as per my inverter

Exact same model my side. Mine clips DC-to-AC at a hair under 5000W; so assuming ~90% efficiency from the 10 panels you're looking at, (10 * 550)*0.9 =4950W from those 10 panels; hence those 10 panels won't ever clip.

12 panels at 90% efficiency would give you around 5940W; so a bit of clipping at mid-day in summer (assuming north-facing panels) to the tune of a maximum of around 900W lost. And if the battery is below 100%, that balance of PV (up to 6500W, so 1500W max) would go there.

So not a train-smash to go 12 panels either.

As mentioned above, over-paneling can make sense to improve production before/after the middle of the day, as well as during winter, and in lousy weather.

 

You know what would take a bit of guess-work out of making recommendations: share a picture of your daily consumption from the Sunsynk app! Pick a busy-ish day and post here. That'll make it easier to make sure supply has a demand to match!

1 hour ago, NadaCT said:

Specs as per my inverter

As can be seen in the 2nd last line under charge mode you can connect 6500W of panels. 

1 hour ago, NadaCT said:

Specs as per my inverter

As above, the solution is still, up to 12 panels, 6 per MPPT, are suitable and the max for your inverter.

Considering your low usage, this panel set should basically meet your Winter demand, but it will be heavily over-specced for Summer, more than double what you need most days. Might be worth it to think about adding aircons or extra fridge/freezers and stuff for summer. Double the pump run-time because... well just because you can...

Otherwise it might be a thought to just put up 6 on MPPT1, and delay the next 6 panels on MPPT2 until Winter, or until you put in more batteries. Or not.

54 minutes ago, GreenFields said:

As above, the solution is still, up to 12 panels, 6 per MPPT, are suitable and the max for your inverter.

Considering your low usage, this panel set should basically meet your Winter demand, but it will be heavily over-specced for Summer, more than double what you need most days. Might be worth it to think about adding aircons or extra fridge/freezers and stuff for summer. Double the pump run-time because... well just because you can...

Otherwise it might be a thought to just put up 6 on MPPT1, and delay the next 6 panels on MPPT2 until Winter, or until you put in more batteries. Or not.

My only issue is that i do not have a north facing roof...so do i please the panels on a split west/east or on my pergola roof which is flat? 

9 hours ago, NadaCT said:

My only issue is that i do not have a north facing roof...so do i please the panels on a split west/east or on my pergola roof which is flat? 

The flat roof is a no go as the winter production will be very low compared to angled panels. 

1 hour ago, Scorp007 said:

The flat roof is a no go as the winter production will be very low compared to angled panels. 

So even a west facing setup will be better compared to flat roof.

52 minutes ago, NadaCT said:

So even a west facing setup will be better compared to flat roof.

Yes. There is actually good production West. If you compared West to East very little difference only difference peak production at different times of the day. 

2 hours ago, TaliaB said:

Yes. There is actually good production West. If you compared West to East very little difference only difference peak production at different times of the day. 

Thank you. Okay then that's settled... now just waiting on quotes to arrive.

5 hours ago, NadaCT said:

So even a west facing setup will be better compared to flat roof.

Yes only in winter. The ideal angle for summer moves from around 35 in mid winter to 8 deg in mid summer for the best yield if facing north. 

One will have to compare a flat roof vs west and know the angle. I presume @TaliaB has done it many times before. 

3 minutes ago, Scorp007 said:

Yes only in winter. The ideal angle for summer moves from around 35 in mid winter to 8 deg in mid summer for the best yield if facing north. 

One will have to compare a flat roof vs west and know the angle. I presume @TaliaB has done it many times before. 

I'd then probably end up with 1 east string and 1 west string... that way i can get early morning generation as well as afternoon/evening generation.

If you can't do north-facing then depending on demand, it may be an even stronger argument to over-panel and go for the 12 (with 6 per string).

Can you share a graph of your daily load (pick a busy-ish day) from the Sunsynk app?

 

16 minutes ago, NadaCT said:

I'd then probably end up with 1 east string and 1 west string... that way i can get early morning generation as well as afternoon/evening generation.

 

Edited February 7, 20242 yr by JayMardern

Every 2nd friday - as we have the domestic in, so she goes boss with appliances, evening usage is relatively the same throughout... 

Your demand is low!

 

With north-facing panels you'd likely get away with just 8 x 550w's; even in winter.

Unfortunately other members will need to chime in on how swapping north for east/west impacts production, though; as I only have experience with north-facers. Would sticking to 12 to compensate for orientation be necessary, I wonder?

 

8 minutes ago, NadaCT said:

Every 2nd friday - as we have the domestic in, so she goes boss with appliances, evening usage is relatively the same throughout... 

 

Edited February 7, 20242 yr by JayMardern

6 minutes ago, JayMardern said:

Your demand is low!

 

With north-facing panels you'd likely get away with just 8 x 550w's; even in winter.

Unfortunately other members will need to chime in on how swapping north for east/west impacts production, though; as I only have experience with north-facers. Would sticking to 12 to compensate for orientation be necessary, I wonder?

 

 

Yeah in winter we use about 600kwh in peak winter.

34 minutes ago, JayMardern said:

Your demand is low!

 

With north-facing panels you'd likely get away with just 8 x 550w's; even in winter. 

Not to sure drawing 400W for about 14hrs as well as the evening cooking having only 1 battery if the battery is a 5 kWh. (not specified) 

The 2nd year with 2 batteries will be OK as more day time generation can be stored.