bottom line is that nobody is feeding electricity back in SA (with the exception of the meter back spinners 🤣 ). It is just not financially attractive. Lots of systems idling away during our beautiful sunny days and Eskom is generating unnecessary dirty power. Something is wrong with this picture. I hope this will change soon. It is doable. Other countries show us how it can be done.

4 minutes ago, plonkster said:

... picture for someone who exports 50% back of what he imports, ...

I have this issue with the cost of that meter plus installation ... line in the sand kind of thing, as it is theirs, not mine.

But now if you maths are spot on correct, Plonk, then maybe this line I drew for myself, is cutting my nose kind of thing. 🙂 

Here is the spreadsheet. I hope it works, it was made in LibreOffice. If I made a mistake, you let me know. I pretty much define an export/import ratio (1 = grid neutral, 0 = no export). With that you can bend the line and see where it crosses the red, which is what you are interested in.

 

coct-tariff-compare.xlsx

Thanks for the graph,

I draw the conclusion that an SSEG residential solar user is penalized for low usage, and only once he starts conforming to a normal usage quota is he not discriminated against.

And that in turn creates a financial incentive that for a band of potential solar export that its better for residential solar to throttle back and stay on the home rate.

The graph indicates in break even around  300kWh, for the realistic conditions given. 

And we can't really neglect the R10K meter cost either. So effectively there is this economic wall, where it either you stop or you crash through it by a mile.

Unfortunately, capacity limits also dictate you will have to stop and throttle your inverters on the home rate.

 

On the other hand, if you are a high rate grid user already, every self-consumed unit that can be generated saves at the high rate unit price.

So there is actually, a much greater incentive to install solar to reduce your usage down to 600kWh /pm, and a less incentive to cover the next 600kWh/pm, and a wall before you can contribute to the social good. To my mind, that's the wrong trend.

 

 

2 minutes ago, phil.g00 said:

And that in turn creates a financial incentive that for a band of potential solar export that its better for residential solar to throttle back and stay on the home rate.

Here I think you are right. It would explain why shopping centers put up solar arrays without asking twice...

4 hours ago, plonkster said:

I did a bit of analysis, and it really seems that all the tariffs are designed to meet at 600KWH. No matter what tariff you are on, whether it be lifeline, domestic or sseg, the first 600kwh costs roughly the same. After that, everyone is treated the same and you pay R2.5575 (even legit LifeLine users). But on the SSEG tariff you get a rebate which you don't get on the others.

There is obviously a model somewhere in someone's computer where they are modelling this and you can see that they've designed the changes to be neutral at the 600kWh point.  Which is probably an average for the >R1m houses.

My view is that the changes are sensible and aligning pricing closer to the way the costs go helps to align everyones interests.

In South Africa there will always be a redistributive element and I understand and accept that that is necessary.

On the technical aspects of SSEG regs - well I think we must have sensible standards - I'd rather follow the poms or the aussies than the germans, but I think Cape Town has a reasonable set of requirements, don't you?

Elbow

41 minutes ago, phil.g00 said:

To my mind, that's the wrong trend.

I agree.

41 minutes ago, phil.g00 said:

And we can't really neglect the R10K meter cost either. So effectively there is this economic wall, where it either you stop or you crash through it by a mile.

Is it? Valid point on the 600 number, but as with the meter costs, the batts are a though nut to crack. Even more so if you are not at home during the day, no pool pump or some such running, your consumption is at night.

Would that not be a good thing to bite the bullet, spend the cost on a meter, and feed back, with, small batt bank purely for Eskom failures?

 

On that note. See a few people lately asking about batts ... as time moves on, more and more banks are going to come up for replacement, some mature some premature. I found in the past the biggest pain lies at replacement ... tend to be around times where one can least afford it.

1 hour ago, The Terrible Triplett said:

I have this issue with the cost of that meter plus installation ... line in the sand kind of thing, as it is theirs, not mine.

But now if you maths are spot on correct, Plonk, then maybe this line I drew for myself, is cutting my nose kind of thing. 🙂 

for us in the Swartland, it is not worthwhile, Import up to 600kw is R1.72 and above 600, it is R2.12 and export is now R0.72 but only up to and equal to your import value. SO you end up paying for three quarters  ......

 

1 minute ago, The Terrible Triplett said:

Would that not be a good thing to bite the bullet, spend the cost on a meter, and feed back, with, small batt bank purely for Eskom failures?

Using @plonkster's feed in 50% of usage, (which is probably fairly realistic, given the capacity limitation), there is this band where unless you can export 300kWh per month the SSEG rate is more expensive than the home rate.

So really you need to have the capacity to consistently export more than 300kWh per month and yet still use 300kWh /m to break even to the home rate at the same usage.

Which might be a gamble, then if you think about it that meter then becomes a R10K bet on that gamble.

And even if you win the bet, its only cents on the rand.

My thinking is, and you have already alluded to it, that a solution will present itself out of necessity on the COCT's behalf, and it will become worth your while to export in the future.

 

 

And that future will be soon, now that the government has managed to add labour unrest to ESKOM's woes.

Edited February 8, 20197 yr by phil.g00

53 minutes ago, phil.g00 said:

And that future will be soon, now that the government has managed to add labour unrest to ESKOM's woes.

Good. Bring. It, On. Am sure a whole lot of small people, big investors, big businesses are getting gatvol. Time WE unite against the Unions.

There comes a time in life where you have to replace that item ... above obviously excludes all wifes - they are perfect and gets better with age, like a good wine.

 

1 hour ago, phil.g00 said:

So really you need to have the capacity to consistently export more than 300kWh per month and yet still use 300kWh /m to break even to the home rate at the same usage.

Right... so you have to be a big consumer with an even bigger PV-array. It has to be "just so" to work. Still, the numbers turned out to be better than I expected.

On 2019/02/08 at 4:39 PM, phil.g00 said:

And that future will be soon, now that the government has managed to add labour unrest to ESKOM's woes.

Load-shedding again, straight in at Stage 2 on a Sunday - well that didn't take long.

Edited February 10, 20197 yr by phil.g00

42 minutes ago, phil.g00 said:

Load-shedding again, straight in at Stage 2 on a Sunday - well that didn't take long.

I find it kinda interesting how often the Helderberg is simply not affected. Somehow we seem to dodge load shedding slots quite easily.

2 minutes ago, plonkster said:

I find it kinda interesting how often the Helderberg is simply not affected. Somehow we seem to dodge load shedding slots quite easily.

As much as I am tempted to say, that you must have some politically connected neighbors.

There are probably  legitimate selective MV loads that they still don't want to load shed if at all possible.

So the network is such that certain load blocks are easy targets size-wise and effort wise.

IOW if there is an essential MV supply they can't open one or two CB's on the HV side of a substation they have to selectively open many more on the MV side.

So plain old "maximum effect for minimum effort" applies, and you're benefiting from that for now.

Unfortunately, as time goes on I think they are going to get a lot more practiced at this.

 

 

you might be on a strategic circuit, that they don't switch unless......

Bishopscourt has a similar luck, circuit and ambassadors residences

Edited February 10, 20197 yr by Mike

53 minutes ago, plonkster said:

I find it kinda interesting how often the Helderberg is simply not affected

not so lucky here in Plattekloof. Power gone down at 13:00. Fortunately there is enough sunshine and I could temporarily connect the oven with the sunday roast in it to the inverter back up circuit 😀

No, not really talking about being on some kind of priority circuit, just that somehow our slots are before 8AM or after 8PM on days when Load Shedding is introduced... and then just as we start planning around tomorrow's slot load shedding is suddenly over again. It's luck of the draw, but we do seem lucky. Of course that entire area 3 (Gordon's bay, Somerset West, Strand) is a HUGE block too.

With all the labour unrest caused by ESKOM unbundling, I hear the unions are threatening to turn the lights back on.

Edited February 10, 20197 yr by phil.g00

On 2019/02/08 at 5:03 PM, Fuenkli said:

bottom line is that nobody is feeding electricity back in SA (with the exception of the meter back spinners 🤣 ). It is just not financially attractive. Lots of systems idling away during our beautiful sunny days and Eskom is generating unnecessary dirty power. Something is wrong with this picture. I hope this will change soon. It is doable. Other countries show us how it can be done.

It's called corruption. Stage 4 load shedding was announced today. Yesterday our neighbors sat without power between 12:00 and 15:00. Yes, there is something VERY VERY wrong here. I could have supplied some electricity to someone else. In fact, most of us, just on this forum, could have contributed a bit to the grid. But they fat cats want to get rich off your efforts.

@Plonkster

 

Suggest update your graph for w/costs.

You also need to add in the line where it makes more financial sense to just go offgrid.

i.e. Solar + Storage.

 

Thats the real danger line for CoCT, and at R2/kw is already over costs.

 

eg  5KW install = 15 panels / 1800 each + inverter 18k + mppt 8k + misc = 60,000

10KW battery = 75k (Pylontech 9.6KW)

135k + vat = 155k

Winter / Summer gen will be covered with 5kw.  Overnight 10kw should be ok for 20kw/day usage.

Add in SHW / LPG if neccessary.

155k  / 10 years / 12 months = 1291/ month, which is pretty similar to *current* coct pricing for 600KW/month with SSEG.

 

 

Well, with the help of a friendly Eskom Engineer my application is in. This is going to be really interesting.

TN-C-S three phase system with a 150A feed (ex farm connection, now used at a private home as original farm now a housing estate and I got the original feed).

3 x Victron Multiplus 5KVA units, one per phase, with 100A transfer switch (all CB at 100A max).
6 KWp rooftop panels feeding into 43KWh batteries (tubular flooded lead acid types) via 2 x Victron MPPT
CCGX and BMS.
Changeover switch (interlocked) plus breaker for inverter input (for off-grid operation).
In front of all this a fat 55KVA three phase Deutz diesel generator with its own fancy monitoring and interlocked automatic change over (Autostart but I use it in manual mode only now).
In front of all that lives a nice Ziehl UFR1000E anti-islanding relay (with parameters set to NRS requirements).

Currently operating in ESS with grid feed in disabled (i.e. grid parallel operation which works really well).

The Ziehl is a recent addition and I do like it - I am not so much viewing it as a anti-islanding system but rather as a protection device for my system. When grid starts up after an outage - funny things happen sometimes. 
 

Keep us informed... I'm also on Eskom!!

Thanks

Edited February 18, 20197 yr by Mark

No not on Eskom - on COCT grid feed. The registered Engineer helping with the application and report is from Eskom. I'm an electronics Engineer - help out Victron with a bit of beta testing on three phase setups sometimes.

Will report back how it's going. Might be a bun fight. We'll see...

Ready to go off-grid with this if they push. That genny puts a decent amount of juice into the batteries in double quick time thanks to three Victron chargers built into the Multis so a nice setup for those days when solar is a bit iffy. Thank's to the now almost extreme programmability of the Multies they can take care of starting and stopping the generator as needed.
Might just need to keep my aircons (seven large ones) on COCT grid but all else can go off-grid if I am forced to.

 

Just got the answer:

"Inverter not on approved list" 

Denied.

So that answers the question if the Ziehl anti-islanding solution which is NRS-097 approved will make a Multi (or for that matter other inverters) legal in COCT's view.

So off-grid, here we come.