display_Name

Appreciate the feedback. My thinking is that the better specs and pricing probably outweigh the downsides here. I wasn't expecting to be looking at Solis again. This thread has me very interested again. Thanks all!

Holy shit. A year ago when I was looking at Solis, they didn't have a 12KW. I was investigating 2 x 6kW Solis inverters. They do now and the specs are insane. Sunsynk 12kW is capped at 15.6kWp PV array, while the Solis is 19.2kW usable with a 24kW max PV array size... It has 6 Strings on 3 MPPTs. How's the software? I suppose I should check out their battery compatibility list. Wonder if they are compatible with Volta batteries?

Decent Pricing as well.

Hello there are other options like the Solis Range they are all LV models with Standard 10 Year warranty fully NRS approved full swap out warranty and you can use a wide range of different LV batteries on these also much higher battery capacity potential their MPPT PV Range is much wider than majority of the products in the market and normally double the capacity of the inverter and also support large panels. They have built in earth neutral bridge bond relays and a very nice intuitive app and web portal. The machines are very robust and can typically handle double their capacity for 10 Seconds so inductive loads are not a problem. Their Utility to battery changeover time is 4ms so you do not notice the changeover. There are also the 30 and the 50 KW Hybrid HV units. They can also parallel up to 10 Units according to the manufacturer.
Power Forum Renewable Energy Store | By Powerforum.co.za
Solis S6 12kW Single Phase Low Voltage Hybrid Inverter
Solis S6 12kW Single Phase Low Voltage Hybrid Inverter Part No: SOL-S6-EH1P12K-NV-YD-L Storage
Power Forum Renewable Energy Store | By Powerforum.co.za
Solis S6 12kW Three Phase Low Voltage Hybrid Inverter
Solis S6 12kW Three Phase Low Voltage Hybrid Inverter Part No: SOL-S6-EH3P15K-NV-YD-L Storage Systems - Hybrid InverterPower Forum Renewable Energy Store | By Powerforum.co.za
Solis S6 15kW Three Phase Low Voltage Hybrid Inverter
Solis S6 15kW Three Phase Low Voltage Hybrid Inverter Part No: SOL-S6-EH3P15K-NV-YD-L Storage Systems - Hybrid InverterPower Forum Renewable Energy Store | By Powerforum.co.za
Solis S6 ADVANCED Three Phase 30kW High Voltage Hybrid
S6-EH3P(30-50)K-H 30K/40K/50K S6-EH3P(30-50)K-H series three-phase energy storage inverter, suitable for commercial PV energy storage systems.

Holy shit. A year ago when I was looking at Solis, they didn't have a 12KW. I was investigating 2 x 6kW Solis inverters. They do now and the specs are insane. Sunsynk 12kW is capped at 15.6kWp PV array, while the Solis is 19.2kW usable with a 24kW max PV array size... It has 6 Strings on 3 MPPTs. How's the software? I suppose I should check out their battery compatibility list. Wonder if they are compatible with Volta batteries?

Decent Pricing as well.

I am satisfied with the basic APP of the Deye. For some that need the real time info of all the measurements it seems Solar Assistant is the way to go.
We are many users here with Deye inverters so ask what you want to see from the Solarman APP and we will gladly share.

Volta inverters are not on the current Coct approved list.
Volta Energy has a network of regional partners across the country to facilitate sales and support:
Cape Town:
Email: [email protected]
Phone: 021 853 3857
WhatsApp: 066 558 7210
Approved Photovoltaic (PV) Inverter List (2).pdf

Wow 78%, folks are not pushing their batteries at all. I drive my battery down to 30% with no loadshedding and 40 when there is loadshedding. The intention is to maximise savings. Hybrid inverters are designed to blend power sources so I can only assume they are can cope with working 24/7.

There are many online scam companies lurking in the shadows some not even in the shadows. Now we have some form of protection identifying legitimate URL on the web. See below link, copy and paste the company URL and run the Detector. 
Scams vulnerability scanner:
https://www.yima.org.za/

Yeah, I really wanted to understand what the deal was with it so I mailed and called people until I got through to a pretty senior engineer in the Energy Directorate managing service connections. I was super thankful that he spent this much effort explaining it so clearly. I understand their position pretty clearly now, and I can't say I argue with any of it. Could things change? Sure... but it will take changing the infrastructure, and planning properly for feedback. With that in mind, they really aren't doing a bad job.
 

Cape Town. Limit is from the SSEG program. They limit to 25% of the breaker (My 60A breaker = 15A export limit = 3.45kVA). I'll be buying one or two more 14.2 kWh batteries (in prep for next winter and ideally and electric car next year). Any excess that those batteries store I'll just feed out to the grid, allowing me to push out longer if not more in one go.

As for the limit, COCT doesn't look likely to get rid of that 25% limit any time soon. Here is some feedback from them on the topic:

 
Hi <Redacted> This is actually such a highly technical and complex matter that one could write a masters or even a PHD thesis on it. However, I will try to provide a brief and simple explanation: 1. Transmission and distribution transformers are designed for power flow from high to low voltage. They can only cope with a limited amount of reverse power flow (exactly how much depends on each transformer design – thus nobody, globally, can provide a definitive answer) before overheating results in premature aging or catastrophic failure. Replacing all of the City’s transformers with units designed to cater for 100% capacity in both directions (these are difficult to design and costly to manufacture) would cost in excess of R 20 Billion. 2. LV reticulation networks are designed to cater for loads and to ensure that at peak load the clients will all receive power within the national parameters, particularly the voltage being 230V +- 10%. For residential areas this peak load occurs on winter evenings, when SSEG does not contribute anything, and the system is designed to ensure that network volt-drop does not result in the customer furthest from a substation experiencing a supply voltage below 207V. During summer days, when the load is low, energy export to the grid would cause the voltage to rise and if too much power is exported the voltage could exceed 253V resulting in damage to appliances. 3. A national working group, taking cognisance of international practices and problems into consideration, developed a document called NRS-097. This national standard is applicable to all aspects of SSEG and includes the 25% of NMD export limit for clients connected to shared infrastructure. 4. In order to cope with the volume of SSEG installations we have established a streamlined on-line and semi-automated application process such that we only need to spend 1 to 2 man-hours on each of the smaller SSEG applications. That 25% export limit avoids having to do a grid hosting capacity and power-flow study (which takes approximately 100 man-hours) for each application in order to avoid grid voltage instability and excessive reverse power flow across distribution and transmission transformers, at least until such time that specific areas have received a high SSEG penetration, which we can see on our GIS SSEG Record map. 5. Those limits also serve the purpose of avoiding situations that compel us to forbid export of energy to the grid by the latest applicants in an electricity network segment because earlier applicants had been granted permission for high power export quantities. 6. Several countries, despite having imposed policies and restrictions similar to ours, are in locations of high SSEG installation volumes experiencing electricity infrastructure problems caused by power export to the grid that they had to implement further restrictions or actively control client’s SSEG system performance. In view of the above, that 25% of NMD export limit will not be lifted in the foreseeable future.


 

Funny thing, we had a similar topic in a recent thread, and someone was insisting that this 25% limit according to NRS-097 was obsolete, and Cape Town was far more advanced, etc. or something like that. Thank you for this feedback from the source.

Cape Town. Limit is from the SSEG program. They limit to 25% of the breaker (My 60A breaker = 15A export limit = 3.45kVA). I'll be buying one or two more 14.2 kWh batteries (in prep for next winter and ideally and electric car next year). Any excess that those batteries store I'll just feed out to the grid, allowing me to push out longer if not more in one go.

As for the limit, COCT doesn't look likely to get rid of that 25% limit any time soon. Here is some feedback from them on the topic:

 
Hi <Redacted> This is actually such a highly technical and complex matter that one could write a masters or even a PHD thesis on it. However, I will try to provide a brief and simple explanation: 1. Transmission and distribution transformers are designed for power flow from high to low voltage. They can only cope with a limited amount of reverse power flow (exactly how much depends on each transformer design – thus nobody, globally, can provide a definitive answer) before overheating results in premature aging or catastrophic failure. Replacing all of the City’s transformers with units designed to cater for 100% capacity in both directions (these are difficult to design and costly to manufacture) would cost in excess of R 20 Billion. 2. LV reticulation networks are designed to cater for loads and to ensure that at peak load the clients will all receive power within the national parameters, particularly the voltage being 230V +- 10%. For residential areas this peak load occurs on winter evenings, when SSEG does not contribute anything, and the system is designed to ensure that network volt-drop does not result in the customer furthest from a substation experiencing a supply voltage below 207V. During summer days, when the load is low, energy export to the grid would cause the voltage to rise and if too much power is exported the voltage could exceed 253V resulting in damage to appliances. 3. A national working group, taking cognisance of international practices and problems into consideration, developed a document called NRS-097. This national standard is applicable to all aspects of SSEG and includes the 25% of NMD export limit for clients connected to shared infrastructure. 4. In order to cope with the volume of SSEG installations we have established a streamlined on-line and semi-automated application process such that we only need to spend 1 to 2 man-hours on each of the smaller SSEG applications. That 25% export limit avoids having to do a grid hosting capacity and power-flow study (which takes approximately 100 man-hours) for each application in order to avoid grid voltage instability and excessive reverse power flow across distribution and transmission transformers, at least until such time that specific areas have received a high SSEG penetration, which we can see on our GIS SSEG Record map. 5. Those limits also serve the purpose of avoiding situations that compel us to forbid export of energy to the grid by the latest applicants in an electricity network segment because earlier applicants had been granted permission for high power export quantities. 6. Several countries, despite having imposed policies and restrictions similar to ours, are in locations of high SSEG installation volumes experiencing electricity infrastructure problems caused by power export to the grid that they had to implement further restrictions or actively control client’s SSEG system performance. In view of the above, that 25% of NMD export limit will not be lifted in the foreseeable future.


 

I joined you this month for the first time now that I am feeding back:


But... that was only from the 8th, and with an export limit of 3.45kVA. This month I'm exporting for the full month. If I was able to push all my excess out however, I'd be able to push roughly 3 times this to the grid.

Yesterday's generation (note the wasted potential... I need more battery)


Sunsynk 12kW Single Phase
14.2 kWh Volta Stage 4
15.6 kWp (28 x 550W Jinko Mono panels)

To answer the OP.... My electricity bill this month will be negative for the fist time, taking the fixed costs into account. And my fixed financing cost is already at least R1k cheaper than my eskom cost was... so I'm saving from day 1.

When I get my second battery, I'll obviously use the excess to feed back in the grid in the evening / morning... but I will use that in winter for more overnight use with heaters. As it stands, with heaters, the current battery is not enough to get through the whole night in winter. At the moment in summer, I still have 50% SOC in the morning, which I push to grid at 7am.

I installed in August, and got the tail end of winter... there was not a single day that I didn't fill the battery for overnight use. Generally in full cloud with rain I'm still generating 2kW.

It’s really not that big an issue and we have NRS that limit capacity export.     The variability in a minute of my solar is LESS than the variability in a minute of my loads.     The grid handles fine my loads ranging eg between 200 and 250kw in a minute, it handles exact same way, my solar export ranging between 200 and 250 kw.
As long as users stick to decent equipment and connect correctly, distributed generation actually IMPROVES the distribution grid because we help lift voltage in the street.    When they get smart, we will get to stage where I only export in peak time of use when they have a big need but then they need to pay me properly.   Then I’ll export from battery a constant kVA value.
There are far too many people spreading doubt, uncertainty, fear.     Usually those councils that don’t like losing revenue, or people selling solutions that need to pretend things are difficult.

Oh no, I was talking about my air source heat pump (aircon) for heating the lounge area. I really want to get a heat pump for my water. I think that needs to be one of my next moves. What I'm seeing at the moment is that the geyser cools down after the kids evening routine, then in the morning it's really not that warm, so I've currently got it on for about 1.5hrs at around 4am to bring it back up to temp (have a timer). I probably need to switch to a heat pump for the geyser as they are a ton more efficient... but I've realised that I also just need another battery as I'm generating a ton of power at the moment (14.2kWh battery full by 11am).

Today's graph:

Red spikes over night are from an oil heater in one of the kid's rooms (I probably need to change that to something more efficient). Then you can see the geyser spike at around 4am. At the moment Eskom kicks in when the battery drains (yellow). Then see how little PV I can actually capture from the day (that red bit from about 10:45 is the geyser another appliance on a timer).

Busy with the SSEG application at the moment. Will at least be able to push 3.45kW back to the grid through the day... but I can see a second 14.2 kWh battery in my future so that I can run a decent heat pump during the night and store more of what I capture (I could definitely use it as it stands).

I'm reading this and my only take is thinking... am I the only person that doesn't iron any more?

But more the the point... the single best part of getting my inverter is that I now understand my consumption intimately.

Install finally completed. I could not be happier. Today will be the first full day of solar production (install completed late yesterday). Ended up with the 12kW Sunsynk Single Phase and Volta Stage 4 (I definitely need a second one, but this is a good start), with 28 x 560W Jinko panels.
Also very very happy with the installer and his team. So professional, and giving the industry a good name. Now I get to register for SSEG and go down that rabbit hole.
Thank you to everyone here for all the tips and suggestions. Everything went a lot smoother than I initially expected in part because I knew what I was heading into, and that's in part thanks to the contributors here.

Oh no, I was talking about my air source heat pump (aircon) for heating the lounge area. I really want to get a heat pump for my water. I think that needs to be one of my next moves. What I'm seeing at the moment is that the geyser cools down after the kids evening routine, then in the morning it's really not that warm, so I've currently got it on for about 1.5hrs at around 4am to bring it back up to temp (have a timer). I probably need to switch to a heat pump for the geyser as they are a ton more efficient... but I've realised that I also just need another battery as I'm generating a ton of power at the moment (14.2kWh battery full by 11am).

Today's graph:

Red spikes over night are from an oil heater in one of the kid's rooms (I probably need to change that to something more efficient). Then you can see the geyser spike at around 4am. At the moment Eskom kicks in when the battery drains (yellow). Then see how little PV I can actually capture from the day (that red bit from about 10:45 is the geyser another appliance on a timer).

Busy with the SSEG application at the moment. Will at least be able to push 3.45kW back to the grid through the day... but I can see a second 14.2 kWh battery in my future so that I can run a decent heat pump during the night and store more of what I capture (I could definitely use it as it stands).

Install finally completed. I could not be happier. Today will be the first full day of solar production (install completed late yesterday). Ended up with the 12kW Sunsynk Single Phase and Volta Stage 4 (I definitely need a second one, but this is a good start), with 28 x 560W Jinko panels.
Also very very happy with the installer and his team. So professional, and giving the industry a good name. Now I get to register for SSEG and go down that rabbit hole.
Thank you to everyone here for all the tips and suggestions. Everything went a lot smoother than I initially expected in part because I knew what I was heading into, and that's in part thanks to the contributors here.

Thanks. Yeah I'm already adjusting consumption to times when I just have a ridiculous amount of additional PV power (setting appropriate timers on equipment etc). The only reason I'd need a second battery is for overnight heat pumps, heating etc outside of the fireplace. But... I'm going to see what it looks like over the next week first... I only started with 80% SOC yesterday because of the late switch on... and this was Day 0.

This is the point that apparently completely escapes the learned Ms Hossenfelder.
She waffles on endlessly about how stupid it would be to generate electricity from fossil fuels and then convert that to hydrogen, which is of course correct.  But then, nobody is proposing to do that.
She also fixates on the efficiency of the process of producing hydrogen and misses the point that halving price of solar-produced electricity has the same effect as doubling the process efficiency.  As we all know, the reduction in cost of solar-produced electricity is ongoing and substantial.
I am not aware of anybody suggesting that hydrogen is an easy solution - the logistical challenges are enormous.  However, if somebody had said to you in the 19th century that you would be able to drive around the corner and fill your car with petrol made from refined oil that has been extracted (often from under the seabed) and brought halfway around the world, that would also have seemed like quite a logistical stretch.  It is a brave soul who makes statements like "Hydrogen is never going to work on any significant level".
There was a popular saying when I was studying engineering: "Those who can, do.  Those who can't, teach".  A modern version might be "Those who can, do.  Those who can't, pontificate on their YouTube channel"

lol, the bit where she says "and that's why the brits left the EU"... hahahaha

Yeah, I think I mostly agree with the sentiment, but I'm not really talking about vehicles (dumb to be on hydrogen imo), or about massive grid scale storage (efficiency is important here). However, what are the other options for longer term distributed renewable storage for power that you make yourself? Is it really just lithium? How do you put several hundred kWh in storage that you produced yourself as excess? I guess it's an itch that I feel I have not scratched properly yet. It feels like with the right tech, even with a lower efficiency, this could be something that can replace diesel generators at a R/kWh. If I'm not able to do anything constructive with the excess kWh from my roof, does it really matter what the efficiency is?

 

@display_Name I agree 100% and would love to have some sort of gas energy storage system but I think that a small scale CH4 from power generator would be a better option than H2, much easier to handle the gas and less likely to spontaneously explode (although still a definite possibility).
Also has the advantage that current domestic stoves, gas heater etc would all work with methane where they would not work very well with Hydrogen (tends to leak through very small gaps)
Something like this https://www.sciencedirect.com/science/article/abs/pii/S2468606919301893 

It is inevitable that end-user tariffs will change to reflect realities.    You’re naive if you expect that you can connect solar, over-generate in the day and draw at night and only pay the for the net kWh consumed in a month.    The grid is not your loss-less and free battery and I won’t subsidize your model.   There are idiots with solar and storage that after evening loadshedding run their loads from grid AND recharge their batteries at 1C, in effect presenting double the kVA load on the rest of the country.   Stuff that!
By FAR the bulk of power and energy is delivered under Time of Use tariffs whether that be to metro or council or large Eskom direct customers.    That involves a NMD fee per kVA, a monthly peak demand fee per kVA, peak/standard/offpeak kWh fees and half a dozen other minor charges.   A few small towns are not on Megaflex.
I’ve done large solar since 2013 and my town was a bit silly at the beginning, giving us 1:1 credits.   I say silly because that ignores that they have the cost of reticulation and maintenance.    That party ended and they went stupid the other direction by slashing kWh (to 115c/kWh) so that solar is compared to that not 275c/kWh and because they know there will be a half hour somewhere in the month that the sun don’t shine, they smacked R415/kVA peak demand.   My response was adding more solar and more storage and grid shaving because I’d be stupid not to.   So now have 425kW solar and 600kWh battery on one of my transformers, will do the others this year.
A fair system imposes a fixed fee based on the size of connection you want available (they reserve and pay for that NMD with Eskom), a variable fee based on that month actual peak kVA (they also pay Eskom for that) and then a Time of Use tariff for kWh.    The fastest way we get people to swap power demand out of peak periods (when the country is paying for R8/kWh peaking diesel and implementing loadshedding) is that peak period energy costs R5/kWh and off-peak costs R1/kWh.   Maybe in a year or two my council pays me to inject 200kVA in peak periods.   I can program that and then recharge between 11PM and 4AM.    If they deducted 100kVA from my demand fees for the 200kVA that I wheel to them plus they pay me half their Megaflex peak cost per kWh, they score and I score.
Smarter tariffs need not be bad for consumers, it can also open up benefits.

It's normally calculated as 25% of the Notified Maximum Demand, where he'd have basically a 60A circuit breaker, which at 230V will have a notified peak output of 13.8kW. And 25% of that is 3.45KVA. Not sure how the 3-phase scenario fits in. Does he maybe have a limit of 3.45kVA per 60A phase?
If you ever find out definitively technically why that limit is so, I'd love to know. There are some old threads if you search the forum with some thoughts of grid stability. Bear in mind if you're exporting full power, it's not impossible that a cloud comes over and the grid suddenly has to pick up the slack for whole neighbourhoods in short time. Extract from the NMBM SSEG doc reads: "As most domestic, commercial and small industrial LV supplies are fed from a shared LV feeder, the maximum individual generation will be limited to approximately 25 % of the customer’s NMD"
In reality more folks these days are buying hybrid inverters in the 8-12kW range or more because of loadshedding. I wasn't even sure if these rules are still being applied. Last chats on the forum I heard just that the inverter's power rating should be lower than the grid power capacity.