Generator or Inverter for residential use?

[Saba'a]

Our average home consumption is between 900-1000kwh a month. In Dec, the 16*405w JA Mono panels generated 937kwh of solar. Panel total is 6.4kw but often goes up to 7kw in the mornings when it’s a little cooler. 6*us2000 batteries are usually charged by noon. I might be able to add another panel on each string, but I’ve hit the practical limit of roof space. I don’t think there is a thing like too much panels; they are the cheapest expense of the whole system after all. Start with 8 panels on one string and if you get more budget, add another 8 panels later on.

Panels are facing just slightly east of true north, not sure the angle but it’s a pretty standard pitched roof.

Just to give you some perspective.

Does the 1000kwh including geyser/s?

 

[Saba'a]

So your roof is largely NNW facing?

I am assuming that your approach would be to design with the final solution in mind, that way you can build it up and not have unnecessary expenses. I am also assuming that your final "dream" solution would be to minimise Eskom entirely. I am going make an educated guess, from your stated utilisation figures I would say that your utilisation is just under 1000 units per month, around 33 units per day?

This means that your final solution would probably need just over 10 KWp in solar panels. The 8.8K Sunsynk can handle 10.4, so it's cool.
It has two MPPTs, each needs a minimum of 150V to start, but I hear that they prefer it closer to 400V. 500V is max, but to be safe I would try not to exceed 425V. Each MPPT can also take two parallel strings, provided that the current does not exceed 18A. I'd say that its pretty flexible.

Looking at panels, you say you have no problem with space which means that you can play with lower wattage (and perhaps cheaper) panels and just get more of them, although there are diminishing returns with cable lengths and mounting hardware. Also, if you are going to do it in phases, you need to consider panel availability, mixing different types, brands and models over a 3 year period could cause all sorts of problems and inefficiencies. I would opt for a strong brand like JA Solar where I know that I can order a specific panel model 3 years after initial purchase and still be able to get it.

So let's look at the JA Solar 455W JAM72S20, was going for just over 2K last year.
You will need 4 panels to kickstart the MPPT, so your absolute minimum will be 4 in 1 series string, using only 1 MPPT. You can put 9 in series without exceeding operating voltage (425v) at NOCT, but if you really want to be safe (think cold winter's day) it probably needs to be reduced to 8. So max 8 in one series string, but they are still only producing 8.72A, so you can add another 8 in parallel. 16 panels are already 7280KWp, and you still have another free MPPT!
Back to efficiencies, consider wiring both MPPTs for this (if the cable runs are less than 38 metres you can use 6mm cable), and then just add panels as you can afford. 22 panels would give you just over 10KWp.

Thanks I think installer said I use about 1000.

I'll try to get 16 panels ( initially budgeted for R3k a panel so R2k a panel will allow me more, just want to allow for installation costs).

 

[gbyleveldt]

Does the 1000kwh including geyser/s?

Yessir, all consumption in the house. Geysers, AC, pool, Oven, etc.

 

[gbyleveldt]

Thanks I think installer said I use about 1000.

I'll try to get 16 panels ( initially budgeted for R3k a panel so R2k a panel will allow me more, just want to allow for installation costs).

The PV brackets, rails, surge protection, switchgear, cabling, etc can be pretty expensive hey. I did the installation myself and even then, all the ancillaries came to around R20k'ish. Installation would probably have been another R20-30k

 

[RonSwanson]

Thanks I think installer said I use about 1000.

I'll try to get 16 panels ( initially budgeted for R3k a panel so R2k a panel will allow me more, just want to allow for installation costs).

16 will be ok until you hit your first overcast spell Make sure your infrastructure plans are expandable to 20+

 

[signates]

Try and get as many panels as you can. Having excess solar on sunny days is not an issue. Its about having enough for overcast conditions. I think my lowest from 8.54kw of panels was 20kwh for the day with winter monthly production expected to be less than 600kwh.

Looking to increase my panels before winter starts by adding another 6 x 305w Canadian solar panels if i can still find them at that time.

 

[Saba'a]

The PV brackets, rails, surge protection, switchgear, cabling, etc can be pretty expensive hey. I did the installation myself and even then, all the ancillaries came to around R20k'ish. Installation would probably have been another R20-30k

Eina! Will get quotes and maybe focus on installation infrastructure setup and then add panels later on.

 

[RonSwanson]

Eina! Will get quotes and maybe focus on installation infrastructure setup and then add panels later on.

what roofing do you have?

 

[Saba'a]

what roofing do you have?

Tiles Harvey type

 

[RonSwanson]

Tiles Harvey type

Interesting. I know Harveytile sell a HSB that looks like it could be cheap, but you will probably need to combine it with with Renusol or Schletter hardware.



My 2c is that you should try to avoid rails if at all possible, they are overkill and quite costly. I was able to install mine on IBR without rails (Renusol Metasole) and it saved a significant amount on CAPEX. It just takes a lot more trouble to do a neat install because what looks like a straight roof is usually canoe shaped and you may need a few hundred spacers.

You may even be able to purchase direct from Schletter in Midrand if your installer can register with them.

Best to speak with Steve at PFS, he knows all the latest methods and techniques.

 

[RonSwanson]

Schletter middle clamp on top, Renusol below:


Renusol middle clamp left, Schletter right:

 

[Sinbad]

My sister seems to be doing eskom's job

No I don't know the specs but it looks like a sweet system

 

[Tariqe]

Good for her !!!!!

 

[signates]

My sister seems to be doing eskom's job

No I don't know the specs but it looks like a sweet system

Helping out as well. That's about ±10 properties just from two home solar setups.

 

[Speedster]

Helping out as well. That's about ±10 properties just from two home solar setups. View attachment 993784

I just had a look at the Tshwane regulations. They pay 10c per kWh pushed to the grid. What a joke.

 

[gbyleveldt]

The weather is a bit gagga today. Not sure how long I can help out as load shedding is supposed to kick in around now.

 

[Messugga]

I just had a look at the Tshwane regulations. They pay 10c per kWh pushed to the grid. What a joke.

Where can one see the details?

 

[Speedster]

Where can one see the details?

Here we go: http://www.tshwane.gov.za/sites/Dep...yLawGazette130dated05Aug2020Pages100to126.pdf

Page 137

 

[Speedster]

I'm still on the hunt for a 3-phase hybrid inverter and stumbled upon the Solis range now. I see power forum are selling them too. Anybody have experience with them? Why are they so cheap?

 

[signates]

I'm still on the hunt for a 3-phase hybrid inverter and stumbled upon the Solis range now. I see power forum are selling them too. Anybody have experience with them? Why are they so cheap?

From what I recall they are not hybrid but grid tie. They also do not have battery connections so you cannot charge a battery directly from them or discharge from a battery if you have load shedding. That the reason for the price difference.