First time poster and long time lurker. I need advice on what you'd suggest for my house for a solar install.

I live in Johannesburg and my house uses 3 phase power and is over 100 years old. I'm in the process of converting to Prepaid, hopefully this will be done soon.
My average usage is 600 kWh, peaking at 700 in July, we ran a heater all night for an entire month. These are my things:

• 3x Gas Geyers
• 1x Gas Stove
• 1x Small Pool Pump
• 1x Electric Oven
• 1x Air Fryer
• 1x Single Fridge
• 2x Double Door Fridge
• 1x Dishwasher
• 1x Front Loader Washing machine
• 1x Dryer (only used in winter)
• 1x Gaming PC

I'm hoping solar will cover the fridges, dishwasher and washer during the day. And my batteries to cover the airfryer / oven (1 hour max), lights, TV's, Laptops, PC's, and occasionally the microwave at night.
I want as much output from panels as I can during the day, but my roof is not ideal. I can fit about 10-12 panels on the north facing side, the rest will have to go on the east and west side of the roof. This is my roof:

My initial budget is R200k, with the idea to extend as my power needs grow. I can extend the budget slightly if needed. To finance, I'm going to take out a loan against my mortgage and pay 40% in cash. I work for a bank, so I get a favourable interest rate.

I need the following information:

1. Please recommend a system that will suit my needs? I’m looking at a 12kW 3P inverter, 10kWh battery storage, and 14-16 panels.
2. How much will it cost? Is much budget sufficient?
3. I don’t really need a 12kW inverter, my estimates are that 8kW should be sufficient, however, I don’t know much about any smaller 3P inverters (Only Deye and Sunsynk seem recommended). I’ve seen Solax and Goodwe 3P inverters, which are cheaper, but I don’t see many people recommending them.
4. If I do get the 12kW inverter, is there a minimum number of panels or kWp that is required?
5. Who do I contact for quotes? I’ve looked at the Power-Forum Store, SolarWay, JC and a few other places. 
    

Have you considered just converting your house to single phase? 

Is pretty simple for the electrician to do and unless you have a requirement for three phase power will definitely be cheaper. 

I would look at a Sunsynk 8kw with 10kw of battery, the Sunsynk batteries aren't bad value and increase the warranty to 10 years on the inverter so maybe worth considering them, otherwise any battery bank capable of supplying 180A @ 48v would be ok for the Sunsynk's. Would definitely suggest getting batteries with BMS's that will communicate with the inverter.  

700kwhr a month = +-24kw/hr a day so you won't need too many panels, depending on your roof, I would guess probably 6000w of panels should be enough comfortably with enough extra to take you through he overcast days as well.  Would try and split them between the East/West roof to get a longer duration of power production. 

8kw Sunsynk has 2 x MPPT so you can only have panels facing two directions. 

@Leshen can help you with installation and you can buy the gear from the Powerforum store

TV lights etc not a problem, Oven on for long time will kill the battery last in about 2hrs at night (not so much of an an issue when there is sun). 

 

If this was my install I would convert the house to single phase. 3 phase is great for industrial irrigation pumps but overkill for a household using 700KWh plus the line charges must be a ridiculous.

Then install 2x 5KW Sunsync inverters (they give you 4mppts to work with for panels on different roofs/orientations). If you decide to upgrade you can always add another 5KW. The 10KWh battery will not last long with a heater running, so it would only be enough could keep essentials running during loadshedding to give you at least lights and PC/TV and possibly carry the baseload through the night.

Finding an installer requires you to look at their references and installs. Better stick to companies that has been around for a couple of years and is a Pty Ltd and not some person that contacted you on facebook. I have seen way too many horror stories. I have even heard about a guy that used to do wedding sound now installing solar.

 

There are many options, as mentioned by the posters above. As an installer 3 phase is a pain. It's a pain because the inverters are pricey & most ppl are out off by this fact. However, there are Good options open to 3 phase operators. There is the 12kW 3P Sunsynk that is pricey & then there is the 2nd Generation Infinisolar produced by Voltronics that has in my opinion superior functions & is more affordable. They come in 12kW & 15kW 3P.

It has 2 AC output ports that can be controlled remotely & both ports can be configured to cutoff at a % SoC via settings. They don't call then Essential & non essential ports just AC port 1 & 2 & you decide what is required. 

This new Gen Infinisolar works with all the same Voltronics battery integration as the Round dialed Single phase Voltronics in that it supports Pylontech, (Lib) FreedomWon to name a few battery options supported. 

At R10k cheaper for very similar abilities I'd say that it's a very competitive machine & the build quality is awesome. IP65 rated is now also a feature. 

But I will totally agree with the other two posters here. Single phase will save you when in comparison to 3P. Less inverter capacity & less batteries required. 

8 hours ago, kamos said:

First time poster and long time lurker. I need advice on what you'd suggest for my house for a solar install.

I live in Johannesburg and my house uses 3 phase power and is over 100 years old. I'm in the process of converting to Prepaid, hopefully this will be done soon.
My average usage is 600 kWh, peaking at 700 in July, we ran a heater all night for an entire month. These are my things:

• 3x Gas Geyers
• 1x Gas Stove
• 1x Small Pool Pump
• 1x Electric Oven
• 1x Air Fryer
• 1x Single Fridge
• 2x Double Door Fridge
• 1x Dishwasher
• 1x Front Loader Washing machine
• 1x Dryer (only used in winter)
• 1x Gaming PC

I'm hoping solar will cover the fridges, dishwasher and washer during the day. And my batteries to cover the airfryer / oven (1 hour max), lights, TV's, Laptops, PC's, and occasionally the microwave at night.
I want as much output from panels as I can during the day, but my roof is not ideal. I can fit about 10-12 panels on the north facing side, the rest will have to go on the east and west side of the roof. This is my roof:

My initial budget is R200k, with the idea to extend as my power needs grow. I can extend the budget slightly if needed. To finance, I'm going to take out a loan against my mortgage and pay 40% in cash. I work for a bank, so I get a favourable interest rate.

I need the following information:

1. Please recommend a system that will suit my needs? I’m looking at a 12kW 3P inverter, 10kWh battery storage, and 14-16 panels.
2. How much will it cost? Is much budget sufficient?
3. I don’t really need a 12kW inverter, my estimates are that 8kW should be sufficient, however, I don’t know much about any smaller 3P inverters (Only Deye and Sunsynk seem recommended). I’ve seen Solax and Goodwe 3P inverters, which are cheaper, but I don’t see many people recommending them.
4. If I do get the 12kW inverter, is there a minimum number of panels or kWp that is required?
5. Who do I contact for quotes? I’ve looked at the Power-Forum Store, SolarWay, JC and a few other places. 
    

Hi there. 
 

You can comfortably produce 50kwh a day with an 8kw Sunsynk with 9500w PV provided the roof is adequate. With 700kwh a month, there is no need for 3 phase, unless you have 3 phase borehole pumps etc. If it was my home, I would convert to single phase and install an 8kw Sunsynk with 2 x 5kwh Lithium Ion batteries and around 14 x 455w panels. 7 north and 7 west. 

Thank you for all the responses. I was definitely considering converting to single phase, as the system would work out cheaper. How much would a 3P to 1P conversion cost?

I've had a look online, the three suppliers that seem reasonably priced and are recommended is Powerforum store, Solarway suppliers and JC solar panels. Solarway suppliers seems to be the cheapest of the bunch. What are your thoughts on these suppliers?

For the inverter, I'll most likely convert to single phase and then save some bucks buying the cheaper 8kW Sunsynk inverter.  For batteries, Dyness, Shoto and Felicity seem to be the best bang-for-buck. I'm intrigued by the Felicity 12.5kWh battery. I had a look at their website and checked reviews online, seems legit. I would like to hear other's opinions. For solar panels, seems demand is high and there isn't much stock. I don't have much roof space and I want the most kWp with the highest efficiency I can get for my money, so I don't mind spending a little extra on panels. I'm looking at the new Canadian Solar 660W panels at Solarway. So this is the system I'm looking at:

 - 8kW Hybrid Sunsynk Inverter
 - Felicity Solar 12.5kWh battery
 - 14x CANADIAN SOLAR 660W panels

Thoughts and suggestions?

Edited November 9, 20223 yr by kamos

Purchased a system from Solarway Suppliers 2 weeks ago and was able to collect the next day. They are legit but are very busy and the one sales guy told me at 8.30 Monday morning he had over 400 new emails in his inbox, also they had a problem with the phone system which appears now to be fixed.

I would advise going in to see them like I did.

 

25 minutes ago, kamos said:

Thank you for all the responses. I was definitely considering converting to single phase, as the system would work out cheaper. How much would a 3P to 1P conversion cost?

I've had a look online, the three suppliers that seem reasonably priced and are recommended is Powerforum store, Solarway suppliers and JC solar panels. Solarway suppliers seems to be the cheapest of the bunch. What are your thoughts on these suppliers?

For the inverter, I'll most likely convert to single phase and then save some bucks buying the cheaper 8kW Sunsynk inverter.  For batteries, Dyness, Shoto and Felicity seem to be the best bang-for-buck. I'm intrigued by the Felicity 12.5kWh battery. I had a look at their website and checked reviews online, seems legit. I would like to hear other's opinions. For solar panels, seems demand is high and there isn't much stock. I don't have much roof space and I want the most kWp with the highest efficiency I can get for my money, so I don't mind spending a little extra on panels. I'm looking at the new Canadian Solar 660W panels at Solarway. So this is the system I'm looking at:

 - 8kW Hybrid Sunsynk Inverter
 - Felicity Solar 12.5kWh battery
 - 14x CANADIAN SOLAR 660W panels

Thoughts and suggestions?

What configuration are you planning to do for your solar panels? How many North? These panels are very big so make sure they fit on your roof. 

 

The Felicity battery has a low discharge rate and is quite new on the market. If your peak load is less than 6kw then it might be fine. It won't be able to handle loads more than 6kw. 

I'm looking at a similar install: 8kW SunSynk + 14.3kWh SolarMD. The best I can fit on my North facing roof is 12x 660w Canadians and I have to do it in "landscape" format. Where did you get your 660w Canadians, Kamos?

2 minutes ago, Sats Nkamoto said:

I'm looking at a similar install: 8kW SunSynk + 14.3kWh SolarMD. The best I can fit on my North facing roof is 12x 660w Canadians and I have to do it in "landscape" format. Where did you get your 660w Canadians, Kamos?

Doesn't the 12 660w panels exceed the maximum DC input voltage of the inverter? 

1 minute ago, Thunderdolt said:

Purchased a system from Solarway Suppliers 2 weeks ago and was able to collect the next day. They are legit but are very busy and the one sales guy told me at 8.30 Monday morning he had over 400 new emails in his inbox, also they had a problem with the phone system which appears now to be fixed.

I would advise going in to see them like I did.

 

I requested a quote from Solarway and got a response in 5 mins. Very impressed so far. I've submitted a request to JC Solar Panels and will be sending a request to Powerforum Store as well.

2 minutes ago, Milan188 said:

What configuration are you planning to do for your solar panels? How many North? These panels are very big so make sure they fit on your roof. 

 

The Felicity battery has a low discharge rate and is quite new on the market. If your peak load is less than 6kw then it might be fine. It won't be able to handle loads more than 6kw. 

I posted on mybb to discuss the discharge rate and came to the conclusion that I won't need high discharge rate. 6kW peak is fine. I'm currently running my entire house on a 7.5kVa generator during LS.

4 minutes ago, Sats Nkamoto said:

I'm looking at a similar install: 8kW SunSynk + 14.3kWh SolarMD. The best I can fit on my North facing roof is 12x 660w Canadians and I have to do it in "landscape" format. Where did you get your 660w Canadians, Kamos?

Both Solarway and JC Solar Panels have stock and are similarly priced.

4 minutes ago, Milan188 said:

Doesn't the 12 660w panels exceed the maximum DC input voltage of the inverter? 

That's a good point. What would be the recommended number of 660W panels for 8kW Sunsynk Inverter?

14 minutes ago, Milan188 said:

Doesn't the 12 660w panels exceed the maximum DC input voltage of the inverter? 

Sunsynk Specs:
Weight: 37 kg
Rated Power: 8,000 W
Min PPT Voltage: 125 V
Max PPT Voltage: 425 V
DC Startup Voltage: 150 V
DC Shutdown Voltage: 150 V
Max Input Voltage: 500 V
Max DC Power: 10,400 W
Max AC Power (5 Minutes): 8,800 W
Surge AC Power (1 Second): 12,000 W
Max DC Current: 44 A
Max DC Inputs: 4
Has DC Fuses: 0
Connector: Screw Terminal
Included Connectors: 0
Efficiency: 96.5 %
Transformer: None
MPPT Quantity : 2
Has Integrated DC Switch: Yes

12 minutes ago, kamos said:

 

I posted on mybb to discuss the discharge rate and came to the conclusion that I won't need high discharge rate. 6kW peak is fine. I'm currently running my entire house on a 7.5kVa generator during LS.

That's good. I would still do some more research on the battery. Find out who the importer is, get detailed warranty documentation explaining exactly how the warranty works, find out where to take the battery if there is an issue and also if there is an issue is will it be repaired locally or overseas (China). 

9 minutes ago, kamos said:

That's a good point. What would be the recommended number of 660W panels for 8kW Sunsynk Inverter?

500V total and maximum 425V on one string. You cannot max this out because during cold weather it can increase above the rated voltage so you must leave some headroom. 

 

4 minutes ago, Sats Nkamoto said:

Sunsynk Specs:
Weight: 37 kg
Rated Power: 8,000 W
Min PPT Voltage: 125 V
Max PPT Voltage: 425 V
DC Startup Voltage: 150 V
DC Shutdown Voltage: 150 V
Max Input Voltage: 500 V
Max DC Power: 10,400 W
Max AC Power (5 Minutes): 8,800 W
Surge AC Power (1 Second): 12,000 W
Max DC Current: 44 A
Max DC Inputs: 4
Has DC Fuses: 0
Connector: Screw Terminal
Included Connectors: 0
Efficiency: 96.5 %
Transformer: None
MPPT Quantity : 2
Has Integrated DC Switch: Yes

These panels have around 45V per panel so 12 * 45V is 540V.

2 minutes ago, Sats Nkamoto said:

Yes VOC of 12 panels is higher than 500V. 

Edited November 9, 20223 yr by Milan188

Thanks for the info. So the 8kW Sunsynk inverter has two MPPT's with a max voltage of 445V. Does that mean it's 445V per MPPT or is that the total max voltage?

If it's per MPPT, 7 x 660W panels per MPPT (315V) should be OK right?

24 minutes ago, kamos said:

Thanks for the info. So the 8kW Sunsynk inverter has two MPPT's with a max voltage of 445V. Does that mean it's 445V per MPPT or is that the total max voltage?

If it's per MPPT, 7 x 660W panels per MPPT (315V) should be OK right?

This is something I am not sure about. I do not have this issue therefore I didn't check. 

My feeling is although the each MPTT can handle 425W the inverter can only handle 500V. But someone please correct me. 

 

Edit: I may be mistaken. I think approx 300V per string should be fine.

Edited November 9, 20223 yr by Milan188

59 minutes ago, kamos said:

Thank you for all the responses. I was definitely considering converting to single phase, as the system would work out cheaper. How much would a 3P to 1P conversion cost?

Not more than 30 minutes labor, isn't a big job at all if they know what they are doing. 

4 minutes ago, Sc00bs said:

Not more than 30 minutes labor, isn't a big job at all if they know what they are doing. 

The question is what phase to use. 

37 minutes ago, kamos said:

Thanks for the info. So the 8kW Sunsynk inverter has two MPPT's with a max voltage of 445V. Does that mean it's 445V per MPPT or is that the total max voltage?

If it's per MPPT, 7 x 660W panels per MPPT (315V) should be OK right?

I think if there are two MPPT's and there is a specification -(MPPT Range – 125~425V) the inverter can take max 425V per MPPT.

21 minutes ago, Milan188 said:

That's good. I would still do some more research on the battery. Find out who the importer is, get detailed warranty documentation explaining exactly how the warranty works, find out where to take the battery if there is an issue and also if there is an issue is will it be repaired locally or overseas (China). 

500V total and maximum 425V on one string. You cannot max this out because during cold weather it can increase above the rated voltage so you must leave some headroom. 

 

These panels have around 45V per panel so 12 * 45V is 540V.

I confirmed with the supplier that the 8kW Sunsynk should safely handle 14 x 660W panels split across the two MPPT's.

5 minutes ago, kamos said:

I confirmed with the supplier that the 8kW Sunsynk should safely handle 14 x 660W panels split across the two MPPT's.

It can safely handle 18

19 hours ago, kamos said:

I don't have much roof space and I want the most kWp with the highest efficiency I can get for my money, so I don't mind spending a little extra on panels. I'm looking at the new Canadian Solar 660W panels at Solarway. So this is the system I'm looking at:

 

Just a side note. All panels are about 20-21% efficient, larger wattage panels simply package more solar cells in a panel. You should look at the dimensions of the roof. You might be able to fit smaller 450W panels in a more optimal configuration and configure 6S2P (or 7S2P) which will be closer to the 20A Max current where the MPPT will clip.

This should then leave you with different options for the second MPPT eg east/west.

Installing a panel with 18A output will not give you any options for a parallel configuration and they will not allow you to overpanel on amps for rainy days

 

Edited November 10, 20223 yr by iiznh

5 hours ago, iiznh said:

Just a side note. All panels are about 20-21% efficient, larger wattage panels simply package more solar cells in a panel. You should look at the dimensions of the roof. You might be able to fit smaller 450W panels in a more optimal configuration and configure 6S2P (or 7S2P) which will be closer to the 20A Max current where the MPPT will clip.

This should then leave you with different options for the second MPPT eg east/west.

Installing a panel with 18A output will not give you any options for a parallel configuration and they will not allow you to overpanel on amps for rainy days

 

Ok, that's food for thought. I am starting the process of getting quotes with installers, I'll check with them to see how many panels would fit onto my roof.

What is the benefit or difference between parallel and series configurations? And what is overpanelling?