City of Capetown feed in option

[vylint]

Hi Folks. I'm researching the option to pay more to be able to feed into the CoCT grid (new special meter and some additional setup). I should get around R1 for each Kwh I export, with max limit of 3.4kwh with my 60A breaker. With solar panels becoming cheaper these days, I'm wanting to over spec on panels so I can feedback excess solar and offset some of my costs.
Has anyone done this successfully? Does it make sense or is it a waste of money? Some installers I've asked say it will work, others say just get more battery capacity.
I dont need to massively profit, more just offset some costs when there is plenty solar and perhaps in winter not need grid power for my household needs.
Cheers.

 

[Frana.mtb]

Doesn't make sense cause your inverter is still doing work to be able to export this power.

+ the cost of the meter and this will take fuck long to break even and then you inverter has probably done quite a few work hours extra it didn't need to.


Ad battery capacity, don't know your house or needs but battery capacity is a far better solution.


Wish I did more battery than panels but alas

 

[vylint]

With my oversimplified maths, it would seem I'd only need to export 400kw per month to fully offset my fixed network charges at a minimum.... anything more would go towards paying back the extra upfront costs of being able to export to the grid.

 

[disquisitive.ape]

Would be great if you showed us your numbers and calculations.

Here is a link to irradiance maps to help you in your investigation (in case you don't know about them).

Solar resource maps & GIS data for 200+ countries | Solargis

The largest collection of free solar radiation maps. Download maps of GHI, DNI, and PV output power potential for various countries, continents and regions.

solargis.com

I think for rough calculations, of interest would be the "Photovoltaic Electricity Potential" for 1kW system map, maybe? For every 1kW installation capacity with system losses of 9% (which I think it too low, but anyways) it will show you the potential generational capacity for daily kWh and yearly kWh averaged over the whole year. I assume the 1kW is the 80% mark of the advertised panel "perfect" generation, i.e. a 1.25kW real world conditions installation.

If you can only feed in 3.5kW (unity PF)/ 3.5KVA, you will still need a FAT battery to capture the full summer days surplus and feed from your battery what surplus you captured.

Would be great to see the calculations on the economics. Remember to factor in breakage and wear and tear.

 

[BlakeQA]

Hi Folks. I'm researching the option to pay more to be able to feed into the CoCT grid (new special meter and some additional setup). I should get around R1 for each Kwh I export, with max limit of 3.4kwh with my 60A breaker. With solar panels becoming cheaper these days, I'm wanting to over spec on panels so I can feedback excess solar and offset some of my costs.
Has anyone done this successfully? Does it make sense or is it a waste of money? Some installers I've asked say it will work, others say just get more battery capacity.
I dont need to massively profit, more just offset some costs when there is plenty solar and perhaps in winter not need grid power for my household needs.
Cheers.

It makes sense if your daily export consistently exceeds the cost of the monthly AMI admin fee, but remember you are capped at 3.4kW regardless of how many panels you install.

The AMI Meter:
According to the guidelines, you must pay for the Advanced Metering Infrastructure (AMI) meter and any installation or accommodation costs upfront.

Monthly Admin Fee:
When you switch to feed-in, you move to the Home User Tariff plus a monthly AMI Administration fee. Your exported power must first "pay off" this fixed fee before you start reducing your actual electricity bill.

The Export Cap:
For a 60A connection, regulatory guidelines (Clause 7.12) generally limit export to 25% of your supply, which is roughly 3.5kVA (approx 3.4kW).

Diminishing Returns:
Even if you install 10kW of panels, you can never export more than 3.4kW at any single moment. Over-speccing is great for cloudy days, but "wasted" during peak sun if your batteries are full and your house loads are low.

Cash for Power:
If your generation credits exceed your total consumption bill, the City will pay you out once a year, provided the credit has reached at least R1000.

Self-Consumption is King:
Since the export rate (approx. R1/kWh) is much lower than the rate you pay to buy electricity, it is always more financially sound to use your solar power for your own heavy loads (geysers, pumps) rather than selling it back.

 

[vylint]

Thank you for that clarity @BlakeQA

Question about the additional monthly AMI Administration fee, can you point me to where you saw this?
I am already on the Home User Tariff (post-paid), so that remains the same no matter which route I take.

Ideally, during sunny periods I can export any excess solar and in cloudy periods I can avoid having to buy units from CoCT for my household needs.

I'm considering putting in 14kw of panels, 12kw inverter and 16kw batteries.....in future I'd look at adding more batteries.

 

[vylint]

I see there is a reference to an additonal AMI admin fee.. .but doesn't seem to specify how much.
https://resource.capetown.gov.za/documentcentre/Documents/Financial%20documents/Budget2526_Ann6_25-ElecGenandDistribution-ConsumptionandGeneration.pdf

 

[Sageofchaos]

I was looking at the feed-in policies from Eskom and they're only offering 40 cents per kW/h to my knowledge?

I laughed and I moved on.

Edit: They also don't want your power between 9am and 5pm. They want it during peak demand, meaning that it will ultimately also deplete your batteries if they do "buy" the excess power you generate.

 

[vylint]

I was looking at the feed-in policies from Eskom and they're only offering 40 cents per kW/h to my knowledge?

I laughed and I moved on.

Being within the City of Capetown area the rate is around R1.16 per kwh now (including the incentive).
No one is going to be using this as a profit generator.... if anything, it helps to pay back the investment a little bit sooner.