3 minutes ago, viper_za said:

@The Terrible Triplett are you paying R0.55

If not how is this even relevant?

That price, ex VAT R0.48c, is what CoCT will pay me per kWh if I was grid tied.

So it is a very valid number to consider for a grid tied solar system - no batteries.

23 minutes ago, The Terrible Triplett said:

That price, ex VAT R0.48c, is what CoCT will pay me per kWh if I was grid tied.

So it is a very valid number to consider for a grid tied solar system - no batteries.

Most grid tied I know use batteries purely as backup. This is now if they have the others as you know die when the grid dies

3 minutes ago, viper_za said:

Most grid tied I know use batteries purely as backup. This is now if they have the others as you know die when the grid dies

Yes we know that. You asked what is the relevance of R0.55c, I answered.

If you add batteries, the cost increases BUT with grid tie you are not using the batts, so they are purely there as backup, like a UPS.

50 minutes ago, The Terrible Triplett said:

That price, ex VAT R0.48c, is what CoCT will pay me per kWh if I was grid tied.

So it is a very valid number to consider for a grid tied solar system - no batteries.

Rather see that as discount on your investment. AFAIK, COCT charge a monthly fee for grid tie as well. And you need to use more energy than you feed back before they pay out. 

18 minutes ago, The Terrible Triplett said:

Yes we know that. You asked what is the relevance of R0.55c, I answered.

If you add batteries, the cost increases BUT with grid tie you are not using the batts, so they are purely there as backup, like a UPS.

If you go and look, been talking about your claim of eskom and batteries so yes not relevant to that part of the conversation

Connection fee coming to Cape Town. Possibly as soon as next year. Will probably be about R200 a month and will be compensated for with a slight reduction in the price sub 600kwh, so that your overall bill works out about the same. It's common knowledge that the SSEG connection fee is R400 a month. The SSEG rate is similarly cheaper up to 600kwh. Basically, they make sure they get enough money from you to cover grid maintenance (and help pay for the lifeline users).

So for less than the price of a 105ah faux deep cycle, per year, you get to use CoCT for "storage" :-)

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5 minutes ago, SilverNodashi said:

Rather see that as discount on your investment. AFAIK, COCT charge a monthly fee for grid tie as well. And you need to use more energy than you feed back before they pay out. 

Correct, to discourage us from going grid tie. Plonkster did the numbers.

Point is, that is what it costs Eskom to sell on with profit.

But you need to factor into that R0.48c ex VAT, panel and inverter replacements, maintenance etc. Same as Eskom does.

If you can do that, you are very well on your way.

Just now, plonkster said:

Connection fee coming to Cape Town. Possibly as soon as next year. Will probably be about R200 a month and will be compensated for with a slight reduction in the price sub 600kwh, so that your overall bill works out about the same. It's common knowledge that the SSEG connection fee is R400 a month. The SSEG rate is similarly cheaper up to 600kwh. Basically, they make sure they get enough money from you to cover grid maintenance (and help pay for the lifeline users).

So for less than the price of a 105ah faux deep cycle, per year, you get to use CoCT for "storage" :-)

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And you also get to enjoy a nice romantic candle lit dinner every once in a while, for free

2 minutes ago, plonkster said:

Connection fee coming to Cape Town. Possibly as soon as next year. Will probably be about R200 a month and will be compensated for with a slight reduction in the price sub 600kwh, so that your overall bill works out about the same. It's common knowledge that the SSEG connection fee is R400 a month. The SSEG rate is similarly cheaper up to 600kwh. Basically, they make sure they get enough money from you to cover grid maintenance (and help pay for the lifeline users).

So for less than the price of a 105ah faux deep cycle, per year, you get to use CoCT for "storage" :-)

Now THIS is a very interesting take Plonkster! Very. 

1 minute ago, SilverNodashi said:

And you also get to enjoy a nice romantic candle lit dinner every once in a while, for free

And I will then apply my EXISTING paid for bank and have it for 10 years ... but will still first go for the nice romantic candle lit dinner! 

2 minutes ago, The Terrible Triplett said:

And I will then apply my EXISTING paid for bank and have it for 10 years ... but will still first go for the nice romantic candle lit dinner! 

yea. my wife miss those "lights off evenings". Somehow it just too much trouble to walk over to the garage and switch off the inverter once in a while. Suppose I could do it now and then. 

I learned, a bit earlier this evening, that our suburb was without power all day long! Had no idea till someone on the whatsup group asked what time the power will be restored. Apparently there is / was a faulty cable somewhere?

Look what the postman delivered...

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5 minutes ago, plonkster said:

Look what the postman delivered...

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Price?

Normal price would be about 10.5k. I got them in exchange for services delivered, so no money changed hands.

About 7k for the Ziehl and 3k for the Carlo Gavazzi.

@plonkster Can you please put up the calculation you made for the Trojan T105 RE's (can't find the post with it)

48V 225Ah R20 000
Then say for the following 3 types of uses
80% SOC 4000 cycles
70% SOC 2750 cycles
50% SOC 1600 cycles

14 hours ago, The Terrible Triplett said:

Today, must be less than R2.28 kWh.

 

OK, but my question was, what electricity price gives you a break even if you plug it into your costing sums?

R2.35. Cheapest I can get T105RE for. Approximately. So technically, if you buy today, and they last the rated 1600 cycles or 5 years, then it's 4 years of cheaper power. If all goes well, nothing breaks, etc. We're close I think, but I've fallen in love with these nice clean and powerful AGMs. So for the moment I would prefer to keep just a backup bank and not cycle them too heavily.

Another number would be R3.50. That's where high end ups batteries sit. So from about R3 upwards per kWh it starts to make sense. At the difference between Eskom increases and inflation we have roughly a 4% per year, so in present terms, how long to turn R2.28 into R3. Probably about 5... if I eyeball it without taking out a calculator.

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9 minutes ago, plonkster said:

R2.35. Cheapest I can get T105RE for. Approximately. So technically, if you buy today, and they last the rated 1600 cycles or 5 years

Thanks Plonkster but surely if you don't do the 50% SOC you should get away cheaper with 80% and 70% SOC.
If you look at the cycle graph its not linear all the way

Why is is the battery cost alone that determines breakeven? Surely it is the whole system?

3 minutes ago, DeepBass9 said:

Why is is the battery cost alone that determines breakeven? Surely it is the whole system?

Yes, but since batteries are being replaced often, many people use it as a baseline. But it does through your calculations off quite a bit!

1 hour ago, DeepBass9 said:

Why is is the battery cost alone that determines breakeven? Surely it is the whole system?

Reason why I look at that, is it determines whether you want to go purely grid-tied, or if you want to add a storage component. Most people would agree that grid-tie pays itself back very quickly. I've heard numbers as low as 3.5 years, but as I recall it is 5-7 years.

Now lets say you live in Spain, or many other places in Europe, and your utility has just slashed the FIT (feed in tariff). Or you live in South Africa and you had to fit a grid-limiter so that a lot of power is actually going to waste.

One might say that the money (for the gti) is spent and forgotten at this point. You have a new problem or a new opportunity (depending on your outlook) and the question is whether it is cheaper to store your surplus, or buy it in from the grid.

Because my system was paid by load-shedding-avoidance, I'm in that bracket. I can literally exclude the cost of the rest of the system, once again, assuming nothing breaks... but that is one reason why I bought an expensive well-known inverter with a good track record... to maximise the chances of that happening :-)

2 hours ago, DeepBass9 said:

Why is is the battery cost alone that determines breakeven? Surely it is the whole system?

Ditto ... the 7 year break even point with Eskom escalations, could be 4 years or 10, and those 7 year estimate does NOT include batteries nor additional expenses to ensure anit-islanding.

When I was given the 7 year break even point on grid tie, with no batteries, I asked the question re. replacement. All the sales guys went very quiet, mumbling a bit, saying yes replacements are going to happen.

Everyone takes Eskom escalations into account to show you your savings from year 7 onwards. But no-one has the numbers with replacements and inflation of the parts.

The moment you add batteries, the entire picture changes completely and it is not 7 years anymore.

Numbers should be done over 20 years, when the panels need replacement. I have a suspicion that no-one is doing that for then the magic of solar will disappear.

NOTE: The above does NOT imply nor suggest that off-grid users fall in the same category. Generator costs or Eskom connection fees make a HUGE difference on the numbers. 

One thing that one has to take into account in this scenario is "What to do with the excess energy in a GTI situation?". Does one waste it or store it in batteries and it is very close to storage being a better option than filling in with Eskom

If one is looking at a solar versus Eskom then remember that if you are willing to use the bulk of the energy during the day then it is a no-brainer. Panels and inverter will pay for themselves in 4-5 years (6-7 for a more expensive inverter).

Jip, most of the quotes I got over the years stress the fact that you need to use the power in the day.

Working from home sorts that quite nicely. If all the people leave the home, it gets complicated.

You guys convinced me. In the long run it's going to be cheaper just to buy all my power from Eskom. Phew... now I can afford to have a different hobby, like playing golf or something.