With the continuing loadshedding (and their proposed new normal of continuous loadshedding) I've decided to bite the bullet and get started on this road. Yes, I know I should have started ages ago but there's never enough time and budget is another factor to be considered. I've been a lurker on this forum for some time to collect ideas on what I think would be the best road for my needs.

But lets start with the needs. I use about 600+ units per month with the geyser being the top dog gobbling roughly half of the average 20+ units that's used per day. The geyser has already been reined in with a Shelly 1PM and at least now I have a better handle on what's used when and can better control the usage due to shifting demands (family). The introduction of this Shelly had a noticeable difference on my electricity usage. Another big player is my server utilising 45% of the 700VA UPS that protects it, so that seems to be about 7.5 units per day? Wow, didn't think it was that high. Maybe I should install another Shelly to measure that. The rest are the usual stuff like fridges, stove, microwave, toaster, kettle, etc. Lights have already changed to LED apart from a few which can't be changed (odd sizes) but those ones are rarely used so not a concern.

What I want is two fold: firstly to not to be impacted all the time by the Eskom loadshedding and secondly to save on electricity bill and be less reliant on a company that doesn't want us to use their product. Ideally I'd like to move towards a solution that doesn't require them at all in the future but budget is the constraint there. So this is what I've come up with: start small with a 5kw inverter and a 5kw battery and enough panels to keep up with base load and to keep the batteries charged. My elected roof is north facing and rough calculations show that I should be able to squeeze 18 panels in (7 x 7m garage). Phase 2 would involve a second 5kw inverter and 5kw battery. Alternatively I could do half the panels and second battery now and get the additional panels and inverter later. As I keep debating the scenario with myself over and over, I might even have to swallow the entire magazine of bullets and go for the full installation and get it over with as I don't really see the situation getting any better. Maybe the bare minimum for me should be one 5kw inverter, one 5kw battery and the full set of solar panels on the roof and rather add a second battery before adding the second inverter?

I've seen debates on this forum about 5kw versus 8kw and understand that 8kw would better cope with larger loads without too much management but since I'm in an industry where we have primary and secondary servers for almost everything it makes more sense to me to rather have 2 x 5kw in total since if the one breaks you can still hobble along at half strength rather than have nothing for a week/month whilst it's away being fixed. A second inverter will also give me two additional MPPT's for PV expansion in the future (maybe east and west but the east cables might be a tad long then). Likewise with my idea of having 2 batteries instead of a single large battery. On the inverter load side I want to use the KISS principle and make all my loads essential. If they're not really essential I'll throw in another Shelly or two to disable certain loads via automation and/or scheduled runtimes.

Addendum: after all that I had an installer here to chat about my ideas and their suggestion is to rather go for single items, eg. a 8kw inverter and a single large battery. According to him none of these have failed on him before but I keep thinking: what if? Yes, I understand it'll be more expensive to go for doubles of smaller units but the advantage of having a backup for your backup (this is already a backup for Eskom's failures) appeals. Other questionable items mentioned by this installer was that the Sunsynk 5kw only has 1 MPPT (the web site shows 2?) and that it's fine to have AC and DC wiring in the same conduit?

And one last question: any good installers in the Cape Town area, northern suburbs to be more exact? The only referral I got from mybroadband which was actually okay'ed by powerforum-store didn't even bother to respond with a sorry we're too busy to talk to you.

That's probably enough rambling for now. Any thoughts, comments, suggestions or pitfalls I've missed?

A lot of information. You are already developing an understanding of where your energy goes and that is the right starting point.

Put in enough panels to get your battery charged and run your day time load on a partially cloudy day or that low yeild period of winter.

My big win in saving grid usage was the bigger battery which gets me through the night with enough in reserve to deal with load shedding should we get to a very overcast morning (open to debate as this is almost a double jeopardy situation as my battery (10 kW) normally does not discharge below 35%).

Understand what your demand is for load shedding. This will help in sizing your battery. Fortunately I could monitor for 15 months before installing panels and upgrading my battery.

 

8 hours ago, p_i said:

Other questionable items mentioned by this installer was that the Sunsynk 5kw only has 1 MPPT (the web site shows 2?) and that it's fine to have AC and DC wiring in the same conduit?

Ok, clear sign that it is time to chat to someone else.

SunSynk has 2 MPPTs both the 5KW and 8KW. The 8KW can just take a higher current so larger panels (or a parralel string)

AC and DC wiring needs to be separate. You are right. Seeing red flags means you already have enough knowledge to know when to walk.

I went for the 8KW, the biggest draw back would be the fan that runs during peak hours to keep it cool. The 5KW is passively cooled and much quieter. The 2X5KW as it will give you more options for panels too. I should have gone for this but the 8Kw is serving me well. 

If you are planning to run a geyser you need either 8 or 10KW(2x 5KW), having only 5KW will lead to constant trips as you try to use your free power during loadshedding. 

I installed a heatpump and my heatpump runs 2x per day 12pm (peak solar, so excess free power) and 3am on battery power (for morning showers) and my heatpump consumes about 1.7KWh per day for the 2 sessions (winter about 2.5-3KWh). This is for 2 showers per day. This made a huge dent in my consumption and allowed me to run the whole house on 10KWh battery.

I would say rather install 2x5KW and 10kwh of battery with 16 panels (18 if you can fit them) and pick the larger 540W panels. You overpanel slightly but will be thankful on rainy days. With some automations and scheduling the geyser you might be 95% off grid and save a bundle every month.

One last thing. I also ran a server, I upgrade to newer hardware a while ago and my power usage more than halved. Now I can still run everything and still be off-grid. 

 

And so we begin...

Does anybody know whether something like the K2 RibClamp like this...

... is the correct fitting to use on roofs like these:

Also, does somebody know what the dimensions of the boxes for the Sunsynk 5kw inverter and Sunsynk 5.32kwh batteries are? I need to determine whether they'll fit in my car or not.

Many thanks.

One will easily fit in your boot and the other on the back seat (sedan type cars). I fitted my 8kw sunsynk into the boot of my A4 - but only just. 

2 minutes ago, Kalahari Cruiser said:

One will easily fit in your boot and the other on the back seat (sedan type cars). I fitted my 8kw sunsynk into the boot of my A4 - but only just. 

My problem is that I have to transport 2 of each, hence me worrying/wondering about the exact dimensions. I can't seem to find these dimensions anywhere, not even on the Sunsynk site. All the sources provide the dimensions of the equipment, not the boxes they ship in.

Edited May 25, 20233 yr by p_i
Additional lines

If I remember, then I'll check tonight. Still have the boxes in my shed. 

On 2023/05/25 at 11:06 AM, Kalahari Cruiser said:

Still have the boxes in my shed. 

Herewith dimensions of the SS 8KW and SS 5kwh batteries - boxed - in case the OP @p_i still requires this. 

I assume it's the box dimensions, given it's on the outside 🤪. 

 

Edited June 7, 20233 yr by Kalahari Cruiser

....and the Sun-Batt 5.32kw

And it was installed last week. With all the rain and horrible weather since installation I was starting to doubt my sanity since the performance was dismal, apart from the lack of loadshedding at home, which was a huge plus but not at that expense. Yesterday I could at last start to smile given the clear skies and I generated 21.4kW with a peak of 4.8kw. I even ran out of things to consume all the "free" electricity so the total for the day could have been higher. Today is another glorious sunny day and the geyser is fully heated. I'm still tweaking settings as I go along and need to start looking at recording some proper real-time statistics. As nice as the Sunsynk app is (not really) I don't want to wait minutes to see the current figures.

There's also lots of niggles which I can't quite put my finger on which someone can maybe help me decipher:

1. Why does it appear as if it's feeding back into the grid (seeing negative readings on the slave unit at times). My installer only had a single CT coil plugged in on the master unit monitoring the feeding line between the main DB and the new DB and I changed that so I have a CT coil on both units on their individual feeing lines. And yes, the CT arrow does point in the right direction and it shows a positive reading when consuming from the grid. The master unit shows 0 when it's not using the grid.
   
2. Why does the inverters still use grid power? I'm seeing between 2.2 and 3.6A being drawn on the Clearline unit on the grid line. Since I have nothing on the non-essential side, I've set trickle usage to 0W. And yes, I've tried a trickle of 10W too, but I still see usage. So why are the inverters consuming grid power when there's ample battery available? If I drop the breaker for the incoming feed the Clearline unit shows 0A, so the inverters are definitely consuming grid power.
3. I also need to request firmware updates since the 15kHz noise is driving my SO nuts. Must this be done on both units at the same time since they're running in parallel?
4. I'm using a CAN connection between the master inverter and the first battery and a link cable between the batteries (link in, link out) and some (limited) battery information shows on the master. The slave inverter doesn't show any battery information. Is this correct or should I recheck the battery cables? I've used normal network cables for these connections but I'm unsure whether that's correct or not? Master on left, slave on right:
   
   
5. There's a hum on the inverter when the DC (or maybe it's AC) temperature rises. I was under the impression that they only have heatsinks and no fans, but maybe I have an older model? My model is SUNSYNK-5K-SG01LP1 but maybe it's simply a fan based on https://powerforum.co.za/topic/10052-sunsynk-5kw/

Thanks!

 

26 minutes ago, p_i said:

Why does it appear as if it's feeding back into the grid (seeing negative readings on the slave unit at times). My installer only had a single CT coil plugged in on the master unit monitoring the feeding line between the main DB and the new DB and I changed that so I have a CT coil on both units on their individual feeing lines. And yes, the CT arrow does point in the right direction and it shows a positive reading when consuming from the grid. The master unit shows 0 when it's not using the grid.

The CT coils MUST/SHOULD be at your incoming live just after your municipal/eskom meter before anything else. This is usually at the entry point of your main db.

Also on the images of the screen you post it is not showing your home grid at all?

 

29 minutes ago, p_i said:

There's a hum on the inverter when the DC (or maybe it's AC) temperature rises. I was under the impression that they only have heatsinks and no fans, but maybe I have an older model? My model is SUNSYNK-5K-SG01LP1

The 5k units have a small internal fan, that only comes when the caps get a bit warm, that fan boosts some cooling over the capacitor bank. If your cover is on you should hardly hear that fan,
 

33 minutes ago, p_i said:

I've set trickle usage to 0W. And yes, I've tried a trickle of 10W too, but I still see usage.

That trickle feed is quite important, the inverter is not quick enough to prevent power going back to the grid when loads switch off, that trickle feed helps mitigate that back-feed a bit. I have found 50watts to be a sweet spot on my setup.

36 minutes ago, p_i said:

I don't want to wait minutes to see the current figures.

You can set the synchronisation updates to 60 seconds (via sunsynk.net login). Less sore thumbs on the app refresh! 

28 minutes ago, Kalahari Cruiser said:

You can set the synchronisation updates to 60 seconds (via sunsynk.net login). Less sore thumbs on the app refresh! 

Really? This is one of my only major gripes with the App/Portal, the 5 minute delay is far too long; so dropping this interval would be amazing! Where in the portal would we do so? I checked the obvious location (the Gateway list) and I do see the current interval (300 seconds), but how do I change it? The 'More' menu just has 'Unbind' as per the screenshot attached.

Thanks!!

31 minutes ago, WannabeSolarSparky said:

The CT coils MUST/SHOULD be at your incoming live just after your municipal/eskom meter before anything else. This is usually at the entry point of your main db.

Also on the images of the screen you post it is not showing your home grid at all?

Everything is on essential, so there's nothing before the inverters. So power from outside flows via the prepaid meter and then into the feed-in inverter breakers (and through the CT coils on that leg). Once past the inverters it flows via the outgoing breakers. Yes, I was breaker happy so I can isolate an inverter should one fail. My CT coils are on the individual feed-in inverter breakers, one CT coil per inverter.

30 minutes ago, WannabeSolarSparky said:

That trickle feed is quite important, the inverter is not quick enough to prevent power going back to the grid when loads switch off, that trickle feed helps mitigate that back-feed a bit. I have found 50watts to be a sweet spot on my setup.

So the trickle feed is not something that it'll consume all the time? I prefer to use as little from the grid as possible; nothing if possible. Maybe my understanding is wrong when it comes to that setting? Why does the master then show 0W all the time? It's only the slave that shows negative usage at times, even whilst large loads like the geyser is active.

38 minutes ago, WannabeSolarSparky said:

The 5k units have a small internal fan, that only comes when the caps get a bit warm, that fan boosts some cooling over the capacitor bank. If your cover is on you should hardly hear that fan,

I can definitely hear the fan when I approach it in the garage. Maybe I should add some quiet extraction fans at the top to suck the air away from the unit. The heatsinks do not feel very hot on the side.

36 minutes ago, Kalahari Cruiser said:

You can set the synchronisation updates to 60 seconds (via sunsynk.net login). Less sore thumbs on the app refresh! 

I'd also love to know where that setting is hiding!

1 hour ago, p_i said:

I've tried a trickle of 10W too, but I still see usage

Mine is set to 20W. I thought it was mainly for frequency synchronisation, but not sure. 

 

4 minutes ago, p_i said:

I'd also love to know where that setting is hiding!

Check my post here:

 

6 hours ago, Kalahari Cruiser said:

Mine is set to 20W. I thought it was mainly for frequency synchronisation, but not sure. 

I'll try 20W and monitor to see if it makes a difference. Loadshedding here now, so the setting won't make a difference right now. *lol*

6 hours ago, Kalahari Cruiser said:

Check my post here:

That setting is not visible to me. I only have the unbind option like @JayMardern. I seem to recall there's different user types on sunsynk.net. I'm a Basic user right now. Maybe that setting is only available to the Installer and/or Advanced user types?

Edited August 2, 20232 yr by p_i
fix user link

44 minutes ago, p_i said:

That setting is not visible to me. I only have the unbind option like @JayMardern. I seem to recall there's different user types on sunsynk.net. I'm a Basic user right now. Maybe that setting is only available to the Installer and/or Advanced user types?

I just signed up a new portal account, shared my plant with that new account as a 'Manager' role (rather than just Visitor) - and it's the same; the menu item is still missing!

I wonder if it's affected by how the gateway binding was done? I'm nervous to unbind it without knowledge of how to re-bind it, though! 😀

On 2022/10/24 at 8:59 PM, iiznh said:

I installed a heatpump and my heatpump runs 2x per day 12pm (peak solar, so excess free power) and 3am on battery power (for morning showers) and my heatpump consumes about 1.7KWh per day for the 2 sessions (winter about 2.5-3KWh). This is for 2 showers per day. This made a huge dent in my consumption and allowed me to run the whole house on 10KWh battery.

I have a similar arrangement. Before I converted to PV the heatpump had already reduced my bill.

We manage our loads carefully at night. Heatpump runs at 6 in the am and then midday, and on a 10kWh battery I am getting through (right now) from about 16:30 to 9:00 the next day without dipping under 40% SOC.

Edited August 2, 20232 yr by Bobster.

1 hour ago, JayMardern said:

I just signed up a new portal account, shared my plant with that new account as a 'Manager' role (rather than just Visitor) - and it's the same; the menu item is still missing!

I wonder if it's affected by how the gateway binding was done? I'm nervous to unbind it without knowledge of how to re-bind it, though! 😀

I've now discovered how to do it. Put in a request on https://www.sunsynk.org/remote-monitoring to change your user level to Advanced User. Use the same details that you used to create your plant. Once they've done that (they did that for me in less than 30 minutes) you will get a Settings option where you currently only have Unbind. Tada, changed to 60s!

4 hours ago, p_i said:

Maybe that setting is only available to the Installer and/or Advanced user types?

Possibly. I set up my SunSynk dongle / wifi pairing / account myself, with full „privileges“ (I think installer level), as I wanted it that way.
 

Glad to hear that you found a solution to upgrade and that you now have 60s sync. Good looking install by the way, and nice to see you’ve got individual DC connectors/fuse links for each battery. I also went that route, and in fact, my two batteries go to a common busbar after the DC disconnectors, and then onward to inverter (one inverter). 

16 minutes ago, Kalahari Cruiser said:

Good looking install by the way, and nice to see you’ve got individual DC connectors/fuse links for each battery. I also went that route, and in fact, my two batteries go to a common busbar after the DC disconnectors, and then onward to inverter (one inverter). 

I have a common battery busbar inside the trunking above the batteries as well. That way I can do 3 or 4 batteries in the future, should I want to in the future. A common busbar is a better solution in my opinion than to daisy chain the batteries.

2 hours ago, p_i said:

I've now discovered how to do it. Put in a request on https://www.sunsynk.org/remote-monitoring to change your user level to Advanced User. Use the same details that you used to create your plant. Once they've done that (they did that for me in less than 30 minutes) you will get a Settings option where you currently only have Unbind. Tada, changed to 60s!

Yeah also only figured this out like a few weeks later...but then a couple of weeks later I took the plunge on Solar Assistant and have not once even checked the SS App since...

6 hours ago, p_i said:

And it was installed last week. With all the rain and horrible weather since installation I was starting to doubt my sanity since the performance was dismal, apart from the lack of loadshedding at home, which was a huge plus but not at that expense. Yesterday I could at last start to smile given the clear skies and I generated 21.4kW with a peak of 4.8kw. I even ran out of things to consume all the "free" electricity so the total for the day could have been higher. Today is another glorious sunny day and the geyser is fully heated. I'm still tweaking settings as I go along and need to start looking at recording some proper real-time statistics. As nice as the Sunsynk app is (not really) I don't want to wait minutes to see the current figures.

There's also lots of niggles which I can't quite put my finger on which someone can maybe help me decipher:

1. Why does it appear as if it's feeding back into the grid (seeing negative readings on the slave unit at times). My installer only had a single CT coil plugged in on the master unit monitoring the feeding line between the main DB and the new DB and I changed that so I have a CT coil on both units on their individual feeing lines. And yes, the CT arrow does point in the right direction and it shows a positive reading when consuming from the grid. The master unit shows 0 when it's not using the grid.
   
2. Why does the inverters still use grid power? I'm seeing between 2.2 and 3.6A being drawn on the Clearline unit on the grid line. Since I have nothing on the non-essential side, I've set trickle usage to 0W. And yes, I've tried a trickle of 10W too, but I still see usage. So why are the inverters consuming grid power when there's ample battery available? If I drop the breaker for the incoming feed the Clearline unit shows 0A, so the inverters are definitely consuming grid power.
3. I also need to request firmware updates since the 15kHz noise is driving my SO nuts. Must this be done on both units at the same time since they're running in parallel?
4. I'm using a CAN connection between the master inverter and the first battery and a link cable between the batteries (link in, link out) and some (limited) battery information shows on the master. The slave inverter doesn't show any battery information. Is this correct or should I recheck the battery cables? I've used normal network cables for these connections but I'm unsure whether that's correct or not? Master on left, slave on right:
   
   
5. There's a hum on the inverter when the DC (or maybe it's AC) temperature rises. I was under the impression that they only have heatsinks and no fans, but maybe I have an older model? My model is SUNSYNK-5K-SG01LP1 but maybe it's simply a fan based on https://powerforum.co.za/topic/10052-sunsynk-5kw/

Thanks!

 

1. Is your CT connected though? It should show you the coil pic just after the pylon tower to indicate its connected...I have 1 x CT coil and it shows on both my Master and Slave inverter. I also see a momentary negative reading at times...my installer reckons its normal and its that split second where the inverter doesn't know what to do with the power.

5. They have a small fan...kicks in when temp exceeds 58 degrees or thereabouts...I was also worried when I heard it for the 1st time. It would run for about 15-30min then shut off again.