Mike's (non-Sunsynk) System

[Saba'a]

Or I am considering if I should rather just go for the 545w panels, they are R400/500 rand a panel more but might be worth it

Yep I have 8 x 545w panels. 19kwh on a sunny day but have even gotten 25kwh on a good day.

 

[itareanlnotani]

Yep I have 8 x 545w panels. 19kwh on a sunny day but have even gotten 25kwh on a good day.

Sunny days aren't the issue. Winter crap days are the issue.

You really want as much generation as you can afford so that winter is still acceptable generation wise.
Otherwise pay $$$ for sufficient battery to support, or hope that Eskom is running.

 

[DuracellBunny]

Nope, it would be very much NOT ok.

9 in series would be max.

Overcast/cloudy conditions can peak past VOC, so 10 panels will DEFINITELY go over, and release the magic smoke from the inverter.

Do NOT do that!

I’m not saying that it should be done but I’m theory it should work not taking into account temperature, the only time you would seemingly go over the voc is in a very cold climate and blistering radiation but this is a rare occurrence. On cloudy or overcast days with a panel temperature of 20 degrees still wouldn’t push the panels past the voc as the panels would have an active load on it.

A decent recommendation if the roof space is available look at a smaller panel so that the controller can be properly utilised as the amperage is 22A on the sunsynks if they haven’t updated this as yet. Which makes it difficult to parallel up another string as the majority of the larger panels are over the 11A mark. This does help to for a later stage to perhaps keep 1 controller free to add a different size at a later stage depending on need because I do see quite a lot that panels available in the past year are no longer available know with some common brands.

Sorry would of replied a bit earlier just been terribly busy.

 

[ands45]

The 8000W is the AC output to power your load.

The DC input limitation is governed by the total voltage of your panels...

I'm looking at the Luxpower LXP 5kw, the DC solar input is 8000w and 550v limit.

 

[itareanlnotani]

I’m not saying that it should be done but I’m theory it should work not taking into account temperature, the only time you would seemingly go over the voc is in a very cold climate and blistering radiation but this is a rare occurrence. On cloudy or overcast days with a panel temperature of 20 degrees still wouldn’t push the panels past the voc as the panels would have an active load on it.

A decent recommendation if the roof space is available look at a smaller panel so that the controller can be properly utilised as the amperage is 22A on the sunsynks if they haven’t updated this as yet. Which makes it difficult to parallel up another string as the majority of the larger panels are over the 11A mark. This does help to for a later stage to perhaps keep 1 controller free to add a different size at a later stage depending on need because I do see quite a lot that panels available in the past year are no longer available know with some common brands.

Sorry would of replied a bit earlier just been terribly busy.

Early winter mornings will see the VOC jump past that, even if amps are low.

I can look at my own MPPT stats and check historic maximum voltages from panels.
They can and do exceed VoC by small margins occasionally, even in SA conditions.

10 x 545 would be outside that margin of safety, which is why I suggest 9 max in 9S setup.


Don't forget, you can have more PV than the inverter will be able to handle - it will clip excess.
Oversizing is fine, just don't exceed the voltage and max amps.

eg - I have 9.5kW of panels connected to my 8kW Sunsynk. It will clip excess in summer (assuming I'm not using it), but in winter, I'll have more generation than I would if I kept it at 8kW.

I think the Sunsynk maxes out at about 10.2kW (need to check the manual again).

 

[SauRoNZA]

Early winter mornings will see the VOC jump past that, even if amps are low.

I can look at my own MPPT stats and check historic maximum voltages from panels.
They can and do exceed VoC by small margins occasionally, even in SA conditions.

10 x 545 would be outside that margin of safety, which is why I suggest 9 max in 9S setup.


Don't forget, you can have more PV than the inverter will be able to handle - it will clip excess.
Oversizing is fine, just don't exceed the voltage and max amps.

eg - I have 9.5kW of panels connected to my 8kW Sunsynk. It will clip excess in summer (assuming I'm not using it), but in winter, I'll have more generation than I would if I kept it at 8kW.

I think the Sunsynk maxes out at about 10.2kW (need to check the manual again).

10,400 W exactly.

 

[AchmatK]

10,400 W exactly.

I've seen higher as long as there is space in the battery for it to go.

DC from solar or batteries to AC is capped at 8kw but if there is space in the battery it will take DC from solar to the batteries.

Can't find the pic now but this is my system pushing 8kw from solar to loads and back to the grid and the balance going to charge the batteries. I think I saw it go as high as 10.6kw from my 10.37kwp solar array.

 

[SauRoNZA]

I've seen higher as long as there is space in the battery for it to go.

DC from solar or batteries to AC is capped at 8kw but if there is space in the battery it will take DC from solar to the batteries.

Can't find the pic now but this is my system pushing 8kw from solar to loads and back to the grid and the balance going to charge the batteries. I think I saw it go as high as 10.6kw from my 10.37kwp solar array. View attachment 1300006

Yeah inverter itself can do a lot more from batteries and passthrough etc.

This is purely from PV input.

 

[Mosgi]

You still need to add in additional DC breakers and other wiring which will bring the cost over.

If you go with multiple units, need to keep firmwares identical, and possibility of software issues that others don't have. I suspect multiple units software isn't tested as well as single units, as less people go with multiple units...

If you're looking at say deye or its variants (sunsynk) - they have 5kw, 8kw, and 16kw units available.

Have a look at your equipment in use, and work out if you really need that much power at once.
I'd consider moving to a gas stove to avoid needing 2-3KW of electricity for cooking, that will bring your max load down.

Reducing Geysers use is another option, as those can chow 3-4KW. A number of different methods available - heat pumps, solar hot water systems, changing element to a DC element and driving directly from panels, or putting in a 2kw AC element instead of the existing 4kw to drop peak usage etc etc.

Once you've done that, the only other major load in the house will be your geyser, and sporadic stuff like kettles or washing machine. A 5kw on its own would probably be fine in that instance, and would be fine in a 3 bedroom if you got rid of the larger single loads (cooker or geyser - or both!)

If you have multiple geysers or a larger house eg a 5 bedroom family, then go with a larger inverter 8kw or 2 x 5kw, or look also at getting the geysers offgrid with solar hot water, or maybe a heat pump.

If you have an electric car, a large roof and lots of play money, I'd go with a 16kw and overspec the crap out of generation.


How big is your household?

Is the significant other or other household residents big users of heavy power items - kettle, hair dryer, washing machine, dish washer, cooking (anything that generates heat chows electricity hard when in use...).

Always mitigate first as its the cheaper option. The less you use, the less you need to spend overall on the solar system.
move - cooking -> gas. Halogens -> bin (replace with decent LED), Geysers -> SHW or Heat Pump etc
Older fridges -> A++++ models

Wow,

Thanks for taking the time for this.

Load is a tricky one, but I can’t plan for just the extremes, I have 3 geysers (6 bed/6 bath excl maids), one services the 2 guest rooms and the other the kids rooms on the one side of the house. So at a full house with guests staying over, I’ll likely see some extreme spikes especially with the pool pump potentially running.

Have 3 phase electricity which from what I’ve been reading suggests I’d need a 3 phase inverter, or 3 separate inverters, which is part of the reason why the single inverters could make sense if that’s my only option.

When the guys wired up the DB board they spent some time balancing the loads, it now the geysers and downstairs lights are on the same phase. The upstairs lights share the plugs and pool pumps. Have gone for two gas stoves instead of one of each since we don’t see us actually needing the electric one. I want to add a pool heater at some stage .

So on summary at its worst it’s a power guzzler but that’s only if we’ve got everyone over.

 

[hj2k_x]

Yeah inverter itself can do a lot more from batteries and passthrough etc.

This is purely from PV input.

I got an overload fault on our Deye 8kw inverter yesterday. Around 16h45. The load was high (oven, some heaters, tumbler) but the app was suggesting only about 10kw total, mixed between battery (about 3kw, solar maybe 1.5 and the rest from the grid). Was not expecting it to trip like that. Thought pass through was meant to be a lot higher. Any ideas?

 

[Koosvanwyk]

I got an overload fault on our Deye 8kw inverter yesterday. Around 16h45. The load was high (oven, some heaters, tumbler) but the app was suggesting only about 10kw total, mixed between battery (about 3kw, solar maybe 1.5 and the rest from the grid). Was not expecting it to trip like that. Thought pass through was meant to be a lot higher. Any ideas?

The max continues AC passthrough is up to 50A (about 12000w) on the essential side.

So if your load is say 10kw on the essential circuits, the the inverter can take up to a maximum of 8kw from solar and battery and will supplement the rest from AC/Eskom.

Have never tried it with over 10000w, max I used was about 9500w

 

[hj2k_x]

The max continues AC passthrough is up to 50A (about 12000w) on the essential side.

So it your load is say 10kw on the essential circuits, the the inverter can take up to a maximum of 8kw from solar and battery and will supplement the rest from AC/Eskom.

Have never tried it, max I used was about 9500w

Ok thanks. It could be that it was just bad timing and for some reason all the big draw appliances peaked at the same time, exceeding the 12000W draw...

 

[SauRoNZA]

I got an overload fault on our Deye 8kw inverter yesterday. Around 16h45. The load was high (oven, some heaters, tumbler) but the app was suggesting only about 10kw total, mixed between battery (about 3kw, solar maybe 1.5 and the rest from the grid). Was not expecting it to trip like that. Thought pass through was meant to be a lot higher. Any ideas?

Deye isn’t Sunsynk though?

 

[hj2k_x]

Deye isn’t Sunsynk though?

The Deye manual says 50A pass-through. I thought that was going to be more than enough.

 

[itareanlnotani]

Deye isn’t Sunsynk though?

For all intent and purposes it is. Same hardware, slightly different software

 

[SauRoNZA]

For all intent and purposes it is. Same hardware, slightly different software

Yeah I’m aware they are, was just implying I wouldn’t go so far as to assume it’s identical across the board.

 

[Koosvanwyk]

Deye isn’t Sunsynk though?

They are manufactured in the same plant. Deye is actually the "original" if you want to call it that. The only difference is the software, importer into SA (which impacts local support) and obviously the sticker on the product.

 

[thehuman]

Remember someone here had a deye or sunsync running the opposite firmware

 

[W@P]

They are manufactured in the same plant. Deye is actually the "original" if you want to call it that. The only difference is the software, importer into SA (which impacts local support) and obviously the sticker on the product.

When I took my Sunsynk in for repairs there were a ton of Sunsynk and Dye inverters lying there for repairs. Same technicians and workbenches working on both.

 

[hj2k_x]

The max continues AC passthrough is up to 50A (about 12000w) on the essential side.

So if your load is say 10kw on the essential circuits, the the inverter can take up to a maximum of 8kw from solar and battery and will supplement the rest from AC/Eskom.

Have never tried it with over 10000w, max I used was about 9500w

If I manage to expand the system in a year perhaps, would adding a further inverter increase the total pass-through accordingly? Would it have to be an identical one or could you mix n match, say 8+5 or 8+10?