Solar Advice's basic off-grid solar power system prices compared

Harmonic said:
Total electricity cost for house A is not R500 p/m. That figure has to include purchase, installation, maintenance and repairs of the solar system. As a bonus it needs to include the opportunity cost of tying up potentially R100-500k in an illiquid, depreciating "investment/asset". As an example R150k in a 6% p.a. account will net you R750 a month
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On average my system generates 14 000kWh per year. At todays tariff of ±R2.50/kWh that comes to R35k in year one that is not going to Eskom or municipality.

Compounded over 10 years and a moderate annual increase of 8% which by year 10 would be R70 000 per year. The system should assist still be able to go on fire a further 5 years before anything needs to be replaced.

It's even worse for house B who will be paying R4 000 every month for usage plus whatever the connection fee will be at that point.

This is my real world data from my setup. Grid provided electricity is more expensive even with expensive lithium batteries. In 2 years time my pv generated electricity will be cheaper than anything CoCT can provide. Screenshot_20220702-231855_Excel.jpgScreenshot_20220702-231749_Excel.jpg
 
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Rocket-Boy said:
You are missing the point, that is what it currently would be with a connection fee tacked on.
It is supposed to be along the lines of:
House A with solar
Connection fee: R700
Usage = 0kWh
Total electricity cost = R700

House B without solar
Connection fee: R700
Usage = 800kWh @ R1/kWh = R800
Total electricity cost = R1 500


But in this case House B isnt either financing R150k worth of system on top of that or hasnt paid R150k out of their savings.

Im not trying to argue with you in terms of what makes sense, I fully agree with you, what Im saying is that the government and municipalities arent interested in what benefits their citizens, they are interested in what benefits their budgets.
Eskom have clearly stated a few times that the days of getting cheap backup from the grid for solar users are coming to an end, that is their goal.
Im in the boat where I would need to finance a system and I have thought VERY hard about it, I have done tons of research and know exactly what I would spec. It would all work very well as things *currently* stand, but if the proposals that Eskom are making actually take place then I would have outlaid a bunch of money and would then have to outlay more to increase battery or generation capacity to go off grid. This all assumes that your municipality will even allow you to cancel your electricity connections, when they are losing money you can bet they find a way to get it back.

If you have a system already then great, you have to hope you dont get screwed.
If you are considering a system then there is a lot more than the basic cost to think about.
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I see i was beaten to the question.

Where can one get this R1/kWh.
 
AchmatK said:
On average my system generates 14 000kWh per year. At todays tariff of ±R2.50/kWh that comes to R35k in year one that is not going to Eskom or municipality.

Compounded over 10 years and a moderate annual increase of 8% which by year 10 would be R70 000 per year. The system should assist still be able to go on fire a further 5 years before anything needs to be replaced.

It's even worse for house B who will be paying R4 000 every month for usage plus whatever the connection fee will be at that point.

This is my real world data from my setup. Grid provided electricity is more expensive even with expensive lithium batteries. In 2 years time my pv generated electricity will be cheaper than anything CoCT can provide. View attachment 1343488View attachment 1343490
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My point was that the R500 p/m cost is misleading. Do your calcs include the opportunity cost?

I'm a firm believer that solar will be cheaper in the long run, don't get me wrong.
 
Speedster said:
I wouldn't go grid tied for residential in SA. The loadshedding outlook just doesn't justify that route
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Well you don’t really have an option in Cape Town, unless you started off grid.

Also if you choose to feed back into the grid now it falls away I believe, it’s now only the stupid meter cost that is a problem.
 
BuckRogers said:
So will a R150k system make 660 kwh in July in Cape Town. We literally don't see the sun for 10 days continuously.
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If you leaned it more to solar panels and less to batteries sure.

But then you’d have nowhere to store what you generate.

My 193k system generated 691 kWh last month, but there are good days and bad days and for that you need battery.

I reckon I need to spend another 50k on one more battery and some more panels and I’m as good as grid-free.
 
AchmatK said:
I see i was beaten to the question.

Where can one get this R1/kWh.
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More importantly where does this R500 fee come from.

It’s a R150. Hardly worth the effort of going without and likely can’t pay for itself in going fully off grid.
 
SauRoNZA said:
Well you don’t really have an option in Cape Town, unless you started off grid.

Also if you choose to feed back into the grid now it falls away I believe, it’s now only the stupid meter cost that is a problem.
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On-grid / grid-connected is far more advisable. Eskom has rendered grid-tied virtually pointless.
 
SauRoNZA said:
More importantly where does this R500 fee come from.

It’s a R150. Hardly worth the effort of going without and likely can’t pay for itself in going fully off grid.
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Just an example if they were to increase it significantly to dissuade people from installing solar.
 
Speedster said:
On-grid / grid-connected is far more advisable. Eskom has rendered grid-tied virtually pointless.
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Sorry I’m very confused now.

Your first comment made it sound like off-grid is the only way to go…now you say on-grid or grid-connected which means the same as grid-tied from my point of view.

Am I failing at some nomenclature here?
 
AchmatK said:
Just an example if they were to increase it significantly to dissuade people from installing solar.
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They would never get away with it. There would be a complete outrage from the lower income groups.
 
Speedster said:
On-grid / grid-connected is far more advisable. Eskom has rendered grid-tied virtually pointless.
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Sorry I’m very confused now.

Your first comment made it sound like off-grid is the only way to go…now you say on-grid or grid-connected which means the same as grid-tied from my point of view.

Am I failing at some nomenclature here?
 
SauRoNZA said:
Sorry I’m very confused now.

Your first comment made it sound like off-grid is the only way to go…now you say on-grid or grid-connected which means the same as grid-tied from my point of view.

Am I failing at some nomenclature here?
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Grid-tied requires an active grid connection at all times.
 
Speedster said:
Grid-tied requires an active grid connection at all times.
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Oh right I’m with you now.

Don’t think anyone actually installs like that surely?

Everyone is either hybrid or off-grid entirely?

Think in an SA context people use grid-tied universally to mean hybrid.
 
SauRoNZA said:
Oh right I’m with you now.

Don’t think anyone actually installs like that surely?

Everyone is either hybrid or off-grid entirely?

Think in an SA context people use grid-tied universally to mean hybrid.
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In the rest of the world grid-tied is very common as you have a reliable grid connection and it is much cheaper going that route.
 
Speedster said:
In the rest of the world grid-tied is very common as you have a reliable grid connection and it is much cheaper going that route.
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Yeah for sure. When you mentioned it now I realised it’s the common way Americans do it.
 
BuckRogers said:
So will a R150k system make 660 kwh in July in Cape Town. We literally don't see the sun for 10 days continuously.
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I have 8x 400watt. In June/July they peak at just over 2kw an hour on a sunny day. That's from 11am to 3pm giving 8kw. 10 to 11am and 3 to 4pm it comes in at around 1.5kw which is another 3kw. So on a good winters day you get around 12kw. Unless you have loads of battery storage or use a truck load of power, that's more than enough to be 90% self sufficient. If you have a pool pump or something that needs to run for a few hours every day just add 4 more panels and run it during the day. I'm down from spending R1500 a month 2 years ago to not spending that in a full year. Unfortunately my inverter can't take a generator as input so I'm grid bound. With a inverter that can take a generator as input spend 15k more and get a 4kva generator. If the weather is bad for a few days start it up 4hrs a day, charge the batteries and use the rest. Worst case it will be required 10 times a year. Then you will technically be off grid and have the generator as backup.
 
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