On 2024/10/23 at 3:28 PM, wolfandy said:

I surely can't be the only one here that has broken the 1 Megawatt-Hour for the month 😜

Edited October 27, 20241 yr by fstofberg
My house uses a lot of power 2 geysers swimming pool heat pump and my network kit pulls about 600W on its own during the day, upgraded to addidtional panels last month will see how it goes from here but so far it's looking good.

On 2024/10/24 at 9:44 AM, Bobster. said:

Is this a household or a business or both? 

Private household

 

On 2024/10/24 at 7:42 AM, WannabeSolarSparky said:

This is the issue though. Fixed "line" charges are coming for everyone soon in some way or another. Once those get set, there will be no end to increases on paying just to have a connection to the grid

and 

On 2024/10/24 at 10:04 AM, Bobster. said:

In fact this happens a lot already.

I am in CPT and on a prepaid meter. My monthly account from CoCT includes R245.03 + VAT for 'Electricity Home User Charge'. So this is what I pay only to have a connection to my house, irrespective of whether I use it or not. 

@Bobster.and @wolfandy In Gauteng Lesedi we work with the old law of Transvaal  . Lesedi charges R467.14 per month just to have a connection.

3 hours ago, Chris Louw said:

@Bobster.and @wolfandy In Gauteng Lesedi we work with the old law of Transvaal  . Lesedi charges R467.14 per month just to have a connection.

I am familiar with die wet van die Transvaal. In Joburg, on the default tariff, it is nearly a grand now (including VAT). Prepaid users pay a mere R200 a month (excluding VAT) just for having the cable enter their property.

Edited October 29, 20241 yr by Bobster.

On 2024/10/24 at 7:14 AM, MdF said:

This is the issue though. Fixed "line" charges are coming for everyone soon in some way or another. Once those get set, there will be no end to increases on paying just to have a connection to the grid 😞

This is the very truth (as I once heard somebody say). In COJ they have long had fixed fees for the default post-paid tariff. This year they introduced R200 + VAT fixed fees for pre-paid users. And I fully expect that die wet van die Transvaal shall be applied and those fees will get nudged a bit northwards come July 2025. 

It is a griping point for me, but for poor folks that R230 a month is causing some pain. This country is getting as bad as the UK, I tell you. One hears stories about folks who can cook or heat the room, but not both.

On 2024/10/23 at 3:28 PM, wolfandy said:

I surely can't be the only one here that has broken the 1 Megawatt-Hour for the month 😜

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.

Edited November 1, 20241 yr by display_Name

16 minutes ago, display_Name said:

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.

Nice, until Eksdom gets its wish and sets the standing change at R500 a month.

14 minutes ago, HendrikBigChief said:

Nice, until Eksdom gets its wish and sets the standing change at R500 a month.

I mean yeah... the money flowing back should average around R1K per month at the moment (perhaps a little less in winter) once I get a full month under the belt. If they decide to make it NOT worth my while to feed back by raising the fees, I'll stop. I thought about that previously and I'm ok with that.

1 hour ago, display_Name said:

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.

Nice 🙂

I'm also at the moment trying to get my system registered for feeding back. My system also gets throttled by lunchtime, so also have lots of wasted potential generation...

2 hours ago, display_Name said:

with an export limit of 3.45kVA

Where are you based? And where is this export limit coming from?

1 hour ago, wolfandy said:

Nice 🙂

I'm also at the moment trying to get my system registered for feeding back. My system also gets throttled by lunchtime, so also have lots of wasted potential generation...

Where are you based? And where is this export limit coming from?

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.

 

2 hours ago, display_Name said:

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.

1 hour ago, GreenFields said:

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.

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.

 

Edited November 1, 20241 yr by display_Name

19 hours ago, display_Name said:

Cape Town. Limit is from the SSEG program. They limit to 25% of the breaker (My 60A breaker = 15A export limit = 3.45kVA).

Thanks. I'm also in CPT - but I was not aware of that limit. That significantly reduces the attractiveness of selling back power to CoCT as it increases the payback duration of the investment required to be able to sell back. How much roughly did you have to invest for the bi-directional meter and the registration?

I was planning to also get everything up and running to sell power back to CoCT, but reading this I am not sure if it is really worth it. By when do you think you will have recovered your investment for selling back?

  

On 2024/10/23 at 3:28 PM, wolfandy said:

I surely can't be the only one here that has broken the 1 Megawatt-Hour for the month 😜

 

Yep same here, the 3 Esener 5.5KW in Parallel don't have the greatest reporting but we've had to supplement with Eskom a bit in winter, our solar rarely idles 🥳

Edited November 10, 20241 yr by biscuitza

On 2024/10/18 at 2:46 PM, Bobster. said:

That's very good performance.

Hi, we installed a 8kW pv system with 18 Canadian 330W panels, 2x 5 kW Synapse inverters and 14.5 Kwh battery storage. This is a most amazing setup and although the Synapse can't feed into the grid and thus we're a little cheaper, we are more than satisfied. I have a pre-paid meter and have added since 2019 about 4x R1000 for bad weather days and set the system on solar/battery/utility last and it works like a bomb. By 16:00 the batteries are usually fully charged  and we make it through the night easily with the heat pump kicking in at 5 in the morning on battery and seldom moves across to utility. Not sure what I have set my batteries to discharge to but it is not below 50% to protect them. We have adjusted to pv and after 17:00 we only use electricity for fridge, lights, outside lights and TV and cook with gas. Washing machine is a new Bosch energy saving and fridge is Bosch AAA. All heavy electricity usage like ironing, dishwasher,welding ect we do during sunshine time and all is good.

I believe that I have built the largest domestic plant in SA.

26 Panels ==> <=13kw Pv

3 phase supply

2x Solar Evt solar water heating, equivalent to 10kwh and 6.5kwh per day

4 x instant water heaters

1 solar to gas fan induced Gas water heater

3 dwellings, the main dwelling is capable of running off-grid indefinitely

On 2024/10/23 at 3:28 PM, wolfandy said:

I surely can't be the only one here that has broken the 1 Megawatt-Hour for the month 😜

The Megawatt-Hour-Per-Month Club? Yes please! All-time-high was last month (October) at just under 1.3MWh though the average is around 1MWh p/m even in winter.

System (details in signature) payback time will be under 4 years. Now (whilst load-shedding is on standby and prices are black-friday-good) is the time to upgrade: if your're on the fence, pull that trigger! Will add some more batteries on my own system with the profits once it's all paid for itself 3 years from now.

 

Only broke the 1MWh in August...October I may have again but got hit with lightning and lost both inverters and battery...was without solar for a few weeks until replacements were installed a few weeks ago. Also did the gas geyser recently so no longer having to run one of the geysers which was a 4kW element...but that's at least all going towards the battery now which is 2 x 10kWh vs the 1 x 15kWh I had before...so will going into the evenings with 100% battery...and so far that takes us to about 01:00 - 02:00 before we use grid again and that's keeping the battery at 50%...I tried to go to 40% last night and by 06:00 it was only on 44%. Boosting the savings now 😎

 

 

3 x 10kw inverters in parallel. A lot of solar panels, 6x100amp bat, 4 houses. Just starting but getting better every month, im waiting for six more batteries. All manage with automation throw home assistant, one irradiance sensor, a lot lot lot of hours hahaahaah, but im happy. Here en Chile is quite expensive these days. 

Friend of mine, on solar assistant since May. 1 Household. 

 

 

I only have a small system - 6x470w panels, 5kw inverter and 10kw battery but it is plenty for my needs. I have been preparing for going off-grid for a long time. Solar geyser, gas stove etc. I only have one more problem to solve - my 3 phase borehole pump has to be replaced. At the moment it is still running off of Eskom as I only have a single phase inverter.

 

54 minutes ago, eugenedp said:

I only have a small system - 6x470w panels, 5kw inverter and 10kw battery but it is plenty for my needs. I have been preparing for going off-grid for a long time. Solar geyser, gas stove etc. I only have one more problem to solve - my 3 phase borehole pump has to be replaced. At the moment it is still running off of Eskom as I only have a single phase inverter.

 

I wouldn't get rid of your pump if you don't have to. 3 phase is actually preferable for speed control over single phase and you can run your 3 phase borehole pump of a single phase supply using a VSD, will also help reduce the large inrush of current required. 

https://cfptechnologies.co.za/product-category/variable-frequency-drives/ 

1 hour ago, Sc00bs said:

I wouldn't get rid of your pump if you don't have to. 3 phase is actually preferable for speed control over single phase and you can run your 3 phase borehole pump of a single phase supply using a VSD, will also help reduce the large inrush of current required. 

https://cfptechnologies.co.za/product-category/variable-frequency-drives/ 

Very sound advice for a low starting load like a pump. 

Hi to all in order to leave the grid you will need 30kw inverter , 60 kwh battery and 30 kw of solar.

39 minutes ago, WJB said:

Hi to all in order to leave the grid you will need 30kw inverter , 60 kwh battery and 30 kw of solar.

Wrong... here we have 5kW inverter, 38kWh battery and 4.7kWp solar...

If you do not want to "manage" your energy usage, in other words, run the dishwasher during sunshine/solar production hours, for instance and don't care about serializing energy use, in other words, run into the kitchen, turn on the oven, the kettle and the microwave all at once, then yes, and I dare say, the 30kW inverter may not be enough, but if you have a brain, engage it before just blindly flipping switches, then, like us, you will just about never reach the 5kW limit of the inverter, we regularly peak up to 4kW, never for very long and have yet to trip the inverter due to drawing too much energy, because we're running too many high consumers at the same time...

Been off-grid since 2020 with an extension lead from the neighbour initially... proper off grid since 2023 and feeding the extension lead to the neighbour, who is now also off-grid.

Edited March 15, 20251 yr by Kalahari Meerkat
Grammatik & speeling :-)