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Scubadude's 8kW Deye / Canadian Solar / Shoto Hybrid Solar Installation


Scubadude

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13 minutes ago, isetech said:

I have customer who have bills which range from R360 per month to R 18 000 per month (these are just the domestic bills) 

There is no complicated maths involved ... throw in a 15 % and then another 15 % electricity tariff increase ... if your bill was R18000.00 last year in June ... this year in November ... your bill will be R23805.00 ... fitting a geyser timer for example is not going to reduce the bill to R2000 per month. 

If 80 % of your consumption is between 6 pm and 6 am ... installing a roof full of solar panels at a cost of over R100k is also not going to reduce your bill to R2000 per month. 

It seems people find it difficult to understand that just doing one thing will not change everything. 

The bottom line ... it is not as simple as just fit solar and suddenly all your electricity tarrifs go to zero. What I have found ... most people dont want a lifestyle change they just want an easy solution. 

With regards to the comment about the valve ... I dont see a problem ... no water under "normal" operation  ... if anything it would be the tap below the installation that would be the problem ... but once the counter top is fitted ... it shouldnt be an issue.

The other thing to consider ... the synsynk inverter an IP 65 rating and the DB's look like they have an ip 65 rating (could be less) but I dont know ... I am sure the person issuing the COC will take all that into consideration. 

The little knowledge I have gained since scratching around in PV field ... anything over a  R5000.00 electricity bill ... installing solar is a wise move and you should get some form of ROI ... unless of course you get ripped off with a off grid backup system. 

 

@isetech 3 months ago I've installed a 10 Kw " two 5 Kw growatt inverters" + 12 X 410 W solar panels, 2 strings facing North and 1 X 100 A/h  5.1 Kw/h LBSA battery, so far all I can say and have the necessary archived info to prove it is that I'm saving +_ R 700 a month. 

I have to admit I'm at home all the time so I can monitor my system performance and switch the loads accordingly. My 3 Kw geyser and electrical stove are connected to my system and my system can cope. on days like the last 3 days, very overcast I've used quite a bit more from the grid as I have the possibility by changing the settings on my inverter from SBU to SUB combining grid + solar to power the house load. 

Ok different story now, summer time and plenty of sun, I will have to wait for the winter to see if I can achieve similar results, probably not.

See last 30 days of my system performance. 457 KW/h from the sun and149 KW/h from the grid, quite a big savings @ R2.00 per Kw = over R 800 this month.

image.thumb.png.039fd460d8fa046f3d93a72809e3830c.png

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Day T+1.

This is a little surprising ... around 4pm my production fell off a cliff. With the roof facing true north, the system essentially goes to sleep as soon as the sun goes south of west, as it does late afternoon in summer.  Guess that will take some getting used to.

Despite a cold and cloudy start to the day, I had good production ... 23.4kWh. It could have been better if the maximum battery charging current was set correctly. I adjusted it from 50A to 90A and immediately the yield went up.  About an hour later the batteries were fully charged - to max out production I started both geysers and a kettle, to top out instantaneous consumption at 7.6kW. At this point, 5kW came off the roof and the rest from the batteries. I briefly saw solar peak at 5.88kW on the display ... this is 92.3% of the design peak capacity and I'm very happy with this number.

Some learnings today:

  • I'll have to reprofile the Geyserwise programming to maximise.
  • Wiring was not split as I requested - part of the house is on non-essential, while the geysers are essential.
  • I'm starting to seriously think about a third battery.
  • Very glad the inverter is in the laundry and not the scullery as I intended - my wife thought the neighbours had rented a jumping castle when the fans came on.  

And then a question - the panels extend a little over the bottom edge of the roof, which causes rainwater to overshoot the gutter and cause a splashing mess.  At the top there is about 120mm clearance between the panels on the right and the parapet - is this a safety requirement or can I ask for the panels to be moved right up against the parapet (say 10-15mm clearance) so have better use of the gutter?

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Edited by Scubadude
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  • Scubadude changed the title to Scubadude's 8kW Deye / Canadian Solar / Shoto Hybrid Solar Installation
3 hours ago, Antonio de Sa said:

@isetech 3 months ago I've installed a 10 Kw " two 5 Kw growatt inverters" + 12 X 410 W solar panels, 2 strings facing North and 1 X 100 A/h  5.1 Kw/h LBSA battery, so far all I can say and have the necessary archived info to prove it is that I'm saving +_ R 700 a month. 

I have to admit I'm at home all the time so I can monitor my system performance and switch the loads accordingly. My 3 Kw geyser and electrical stove are connected to my system and my system can cope. on days like the last 3 days, very overcast I've used quite a bit more from the grid as I have the possibility by changing the settings on my inverter from SBU to SUB combining grid + solar to power the house load. 

Ok different story now, summer time and plenty of sun, I will have to wait for the winter to see if I can achieve similar results, probably not.

See last 30 days of my system performance. 457 KW/h from the sun and149 KW/h from the grid, quite a big savings @ R2.00 per Kw = over R 800 this month.

image.thumb.png.039fd460d8fa046f3d93a72809e3830c.png

You weren't a big power user to start off with, and I think your solar fraction is pretty impressive! What software is that?   

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3 hours ago, Antonio de Sa said:

@isetech 3 months ago I've installed a 10 Kw " two 5 Kw growatt inverters" + 12 X 410 W solar panels, 2 strings facing North and 1 X 100 A/h  5.1 Kw/h LBSA battery, so far all I can say and have the necessary archived info to prove it is that I'm saving +_ R 700 a month. 

I have to admit I'm at home all the time so I can monitor my system performance and switch the loads accordingly. My 3 Kw geyser and electrical stove are connected to my system and my system can cope. on days like the last 3 days, very overcast I've used quite a bit more from the grid as I have the possibility by changing the settings on my inverter from SBU to SUB combining grid + solar to power the house load. 

Ok different story now, summer time and plenty of sun, I will have to wait for the winter to see if I can achieve similar results, probably not.

See last 30 days of my system performance. 457 KW/h from the sun and149 KW/h from the grid, quite a big savings @ R2.00 per Kw = over R 800 this month.

image.thumb.png.039fd460d8fa046f3d93a72809e3830c.png

Nice. Only thing you're not possibly accounting for in your savings is the tariff bracket you'd be pushed in had you not been using solar. If anything your savings are likely a bit more. 

I'm in a similar position on a smaller scale, for now. Only have 3x 490w panels for now and a single growatt but my savings this month so far is R490. The savings are welcome but secondary to why the solution was comissioned. Staged plans afoot to change that and try and achieve energy independence. 

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11 minutes ago, Scubadude said:

You weren't a big power user to start off with, and I think your solar fraction is pretty impressive! What software is that?   

You quite right my daily consumption averages 25 KW/h, household 3 people, I'm retired but I have my son working from home, apart from the geyser and the stove the rest of the appliances are all low consumption. 

The software was designed by my son, specially programed for my  inverters ( Growatt ).

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9 minutes ago, JoeyhZA said:

Nice. Only thing you're not possibly accounting for in your savings is the tariff bracket you'd be pushed in had you not been using solar. If anything your savings are likely a bit more. 

I'm in a similar position on a smaller scale, for now. Only have 3x 490w panels for now and a single growatt but my savings this month so far is R490. The savings are welcome but secondary to why the solution was comissioned. Staged plans afoot to change that and try and achieve energy independence. 

You are 100% correct I use to purchase R1200/ month for my pay meter @ R 2,05 per unit, now I can do with R 400/ month @ R 1,57 per unit, and the biggest gain.... no more load shedding.

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30 minutes ago, Antonio de Sa said:

You are 100% correct I use to purchase R1200/ month for my pay meter @ R 2,05 per unit, now I can do with R 400/ month @ R 1,57 per unit, and the biggest gain.... no more load shedding.

That's great. The last time I bought electricity was in September 2020.

#NoBraggingRights 😁

 

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1 hour ago, Tariq said:

@YellowTapemeasure, I use from 0.3 to 1 kWh, partly due to the 20 watt zero export feed in, so far this month, pv is 636 kWh  and grid consumption is 25.8 kWh, how do you do it, not having to buy from the grid

If you are self sufficient, why not switch off mains and save the 1kWh per day?

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The discussion about rate brackets made me realise Tshwane is raping is. My average unit cost since 1 July when the new tarriffs came into effect is R 2.80 - these sliding scales are really punitive for large households.  Either way, this is a rough analysis of the benefit I hope to ahieve, ignoring time value of money and tariff hikes for the sake of simplicity.

High Concumption Month Ex VAT c Incl VAT c R/kWh kWh Before kWh After R Before R After Saving
Block 1 (0 to 100kWh) 195.130 219.521           2.20 100 100  R     219.52  R  219.52  R              -  
Block 2 (101 to 400kWh) 228.350 256.894           2.57 300 300  R     770.68  R  770.68  R              -  
Block 3 (401 to 650kWh) 248.790 279.889           2.80 250 0  R     699.72  R           -    R     699.72
Block 4 (more than 650kWh) 268.200 301.725           3.02 550 0  R  1 659.49  R           -    R  1 659.49
Grid Feed Credit 11.990 13.489           0.13          R              -  
Total 1200 400  R  3 349.41  R  990.20  R  2 359.21
Reduction / Saving                             67%                        70%  
Average Municipal R/kWh            R          2.79  R       2.48  
                 
Low Consumption Month Ex VAT c Incl VAT c R/kWh kWh Before kWh After R Before R After Saving
Block 1 (0 to 100kWh) 195.130 219.521           2.20 100 100  R     219.52  R  219.52  R              -  
Block 2 (101 to 400kWh) 228.350 256.894           2.57 300 100  R     770.68  R  256.89  R     513.79
Block 3 (401 to 650kWh) 248.790 279.889           2.80 250 0  R     699.72  R           -    R     699.72
Block 4 (more than 650kWh) 268.200 301.725           3.02 250 0  R     754.31  R           -    R     754.31
Grid Feed Credit 11.990 13.489           0.13          R              -  
Total 900 200  R  2 444.24  R  476.42  R  1 967.82
Reduction / Saving                             78%                                81%  
Average Municipal R/kWh            R          2.72  R       2.38  
                 
Expected Saving per Year  R     25 962.19              
System Cost  R   125 000.00              

Payback (Years)

                   4.81              
             
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On 2021/11/27 at 6:55 AM, Scubadude said:

OK, as I posted elsewhere I was looking out for a Black Friday deal for a "8kW System" - hate that way of thinking because I don't believe 8kWp PV, 8kW inverter and 8kWh storage is a balanced system for most users - almost certainly it will be way heavy on panels and light on storage, resulting in lots of unused energy. 

I got lucky with a super deal, fully installed with COC essentially for a little less than I could buy the main components in the retail market.  In the end, my selected equipment reads like this:

  • 14 x Canadian Solar CS3W-455MS HiKu Super High Power Mono PERC modules - that is 6.37kWp but with my roof angle of 7° I will start with a 8 or 10% drop off the bat
  • 8kW Deye SUN-8K-SG01LP1
    -US/EU Inverter
  • 2x Shoto SDA10-48100 5.12kWh LiFePO4 batteries for 10.24kWh of storage.

I think I'm still panel-heavy and storage-light but I do believe it is better balanced than a typical "8kW system". And a third battery is only a card swipe away...

My installation started on Thursday, and will only be completed later today (Saturday), but here are some early pics:    

 

Care to share who did the installation?

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12 hours ago, Scubadude said:

If you are self sufficient, why not switch off mains and save the 1kWh per day?

need the grid connection, in case the loads are over 5 kW ( have a 5 kW Sunsynk ).

wife calls me Uncle Scrooge, she says even though I have cut my grid consumption by 95% in summer, i am still looking for the last 5 % !!!!!!!!!!!!!!!!!!!!!!!!!!!!!

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T + 2 Days

So the whole house ran off the batteries the whole night. Because of the boost I gave the geysers yesterday no morning topup was required, leaving the batteries at just over 30% at breakfast time.  Then I noticed some grid draw - I have the "Battery Start" setting on 30%, depite timeof use showing 20%.  Quickly fixed that and this allwed the batteries to drain to 26% before solar production exceeded load.

In an effort to replicate yesterday's manual geyser boost I set the conventional geyser to go to 65°C between 13:00 and 15:00, and the solar geyser to do the same from 15:00 to 16:00 (afraid I may boil it if I ramp up the temperature early).  This worked, but my timing was out - despite the semi overcast weather the batteries were fully charged by 12:00, leaving and hour gap in production before the first geyser kicked in.  With the stormy weather in the afternoon I had to use some battery power to top up the solar geyser.  21.6kWh generated for the day - above the 2/3 of 30 kWh I am aiming for so satisfying enough.

image.png.15619ccbb95f4897cec7371979be7f08.png 

Interesting - minor differences between string 1 and 2 during the day ... would love to see this on a clear day to estimate the shading effect of my twin palms. 

image.thumb.png.7986c0933a11c34c13adb27dcb0ec7b1.png

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  • 2 weeks later...

OK, so a lot of things happened since my last post.  The installaer has been great, but the experience has tested my patience as well as his.

Firstly, the loads were not connected correctly, with half the house not on the inverter, and the oven and geysers on essential. This was corrected (decided to keep the geysers on essential to maximise self-concumption through Geyserwise timers), but the CT coil was installed incorrectly after the non-essential loads. 

My carefully typed out and illustrated changes did not help, as I got home to find the geysers and oven now wired to Aux.   

"But you wanted to used excess solar for the oven?!?!"

"Excess solar, yes. Battery power, no. And I must be able to use it even if I dont have enough solar production."

So it was rewired again, and this time I checked everything myself and made sure the CT coil was moved where it should have been in the first place.

I got about a week of reasonable production (around 20kWh per day) dispite lots of clouds and rain. Then we had loadshedding two weekends ago, and when the power came back on we had an earth leakage trip. The same thing happened after the second loadshedding stint. I contacted my installer and emailed Deye customer care. 

That Monday night my board was rewired twice one EL split into 3, but the problem remained.  Just before midnight I booted them out, switched to Eskom and went to bed. The next morning I simulated loadshedding and the EL tripped as the power came back on. That evening the electrician convinced me it was my alarm system PSU that caused the trips and I replaced it, and also disconnected LED flood lights and surge-protected multiplugs, both of which are reprotedly troublemakers when it comes to earth leaks.

The next morning I simulated power failures again, this time with all circuit breakers off. And again, just as the power came back, the earth leakage dropped again. So the next day the installer and electrician picthed up late afternoon and did all sorts of tests. Turned out I had a faulty switchover (which made contact mometarily in the "neutral" position) and one surge protector had blown.  More importantly, there was a fairly constant +/- 130V on the inverter output.

The inverter was removed and said to have a faulty board.  It is expected to be replaced tomorrow.

What bothers me is I dont see an earth neutral bond relay in the installation.  Anyone cares to share a picture or two so I know what to look for?   

P.S. .... save for two emails that told me to switch on the inverter so they could check the inverter data, Deye customer service was completely MIA.  

Edited by Scubadude
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On 2021/12/13 at 5:00 PM, Scubadude said:

What bothers me is I dont see an earth neutral bond relay in the installation.  Anyone cares to share a picture or two so I know what to look for?   

OK, so the sparky put me out of my misery ... in South Africa neutral is bonded to earth in the box on the sidewalk. One of the standard COC tests is for "Elevated Voltage on Neutral", i.e. voltage between incoming neutral and external earth (ground) ... or an incomplete bond. So no relay required. 

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3 hours ago, Scubadude said:

OK, so the sparky put me out of my misery ... in South Africa neutral is bonded to earth in the box on the sidewalk. One of the standard COC tests is for "Elevated Voltage on Neutral", i.e. voltage between incoming neutral and external earth (ground) ... or an incomplete bond. So no relay required. 

Your sparky is correct in a situation when Eskom power is available, however when you loose Eskom power then you loose earth bonding.  Hence the need for a relay to bond neutral and earth when in islanding mode

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1 hour ago, Scubadude said:

As I understand it the inverter's neutral is permanently bonded to earth.  If both on grid and off grid has 0V on neutral, why would it be necessary change anything between modes of operation? Or am I missing something?

Because it is illegal to have a second permanent earth neutral bond.  SANS requires a separate bond to be created only when the system is in islanding mode.

Selection_439.png.27fdfdc72c123aafc077efe799095899.png.64eb0401e54a11543c5d5df15ab852e1.png

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And that is exactly why my brand new installation blew the MPPT controller in the hybrid inverter during commissioning.

The 5KW system was installed by a local electrical contractor who was supposed to know better.

They installed a manual transfer switch so that we could work on the system when in bypass (Mains).

The first time they switched from inverter to bypass and back - the MPPT blew up because the inverter no longer had a N to E bond.

I am now battling to resolve this crises just before the holidays.

I should have been enjoying my savings, instead I am forking out to remedy the errors.

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14 minutes ago, RetiredDIY said:

And that is exactly why my brand new installation blew the MPPT controller in the hybrid inverter during commissioning.

The 5KW system was installed by a local electrical contractor who was supposed to know better.

They installed a manual transfer switch so that we could work on the system when in bypass (Mains).

The first time they switched from inverter to bypass and back - the MPPT blew up because the inverter no longer had a N to E bond.

I am now battling to resolve this crises just before the holidays.

I should have been enjoying my savings, instead I am forking out to remedy the errors.

@RetiredDIY

Just a question, is this necessary with all inverters or only with the Deye Hibrid inverters? I'm now a bit concerned as my system ( 2 X 5 KW Growatt ) does not have N to E bond.

Edited by Antonio de Sa
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Hallo Antonio,

My electrical engineering background and @Bloubul7quote of the regulations agree that back emf during system switching can cause you to lose the system as if you had a lightning strike. Some systems could be better than others BUT the rules are not there for nothing.

If your inverter - at any switching combination - shows a potential of more than 0.5volt between its INPUT E to N or its OUTPUT E to N OR you are nuisance tripping your EL device - you may have a potential problem. There are numerous publications that describe the effects of back emf during transfer switching whether it is manual or auto.

In my case I probably forced the issue in that I instructed the contractor to go through all the operating modes.

The intention was that I could prepare a SOP manual that would assist my household in case of emergency. It turned a pleasant day into a disastrous one.

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