Planning a solar system

Crusader

Crusader

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After 24 hours without power over the weekend and another 8 hours last night it looks like it's finally time to start looking at getting a solar system.

What should I be looking at in determining size of the system required. Our total usage is about 1500 kWh a month for the entire property (1 main house + apartment).

There's a 3-phase main distribution board and the house and apartment have their own DB boards. I'll be looking at doing the initial system for the apartment only as I assume it would be better to do separate systems for each.

Would it be possible for the property to downgrade to single phase power once solar has been installed since the basic usage fee for 3-phase power is quite expensive?

Any recommended installers I can look at who'll cover small Karoo towns between Outshoorn and Beaufort West?
 
You are going to need someone who can source you a big star, then you need to find some way of making it explode into a large cloud of stellar material. Once you do that, you can wait about 4.6 billion years and you will have yourself a solar system :p
 
I used an Engage Efergy to monitor my usage for the last 2 years. When I decided to install a solar system I had all the data to make an informed decision. I could see what my usage was, what my peaks were, and when my peaks were. According to that, I built my system. See if you can get one of those to monitor your usage and generate data to make the decision easier.

I never have peaks of over 6.5kW to 7kW. So I decided on the 8kW Sunsynk inverter for a bit of headroom. My geysers are on a timer to run from 13:00 to 16:00 during the day from the PV Production. Only have 1 Hubble 5.5kW batter at the moment but will most likely get another one. The whole house is on the essential side. Did not split loads.
 
You get 3 phase inverters as well. But if you want to get rid of the 3 phase that will work as well.

For 1500 kWh a month you are looking at roughly 50 kWh a day which is on the high side.

Start by reading these:

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Snyper's Solar Farm

Hi all, I am finally getting round to making this thread. After loads of research and another bout of load shedding I finally decided to pull the trigger and load shed Eskom. Prior to going solar I already had all the lights on LEDs, house is kitted with energy efficient appliances and...
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Maxxis’ Power Plant

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W@P's Solar System

My system has been installed and started running today. I have the following. 1 x 8kw Sunsynk Inverter 16 x 420w Canadian Solar Panels 2 x CBI Astutes (For geyser timers) Riot Cloudlink Edit: Added another Hubble Am-2 TOTAL COST: R171,385.80 I still have my generator connection if...
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You need to decide if you want to have backup power during outages for critical equipment only, or almost off grid or completely off grid.

You can then size the panels and batteries to cover your needs. Cost will vary from R80k to R200k or more depending on what you want to achieve.
 
Hi Crusader ... I have a domestic 3 phase supply and went with a Sunsynk 12kw 3 Phase inverter in Sept 2021.
My usage is around 30kwh per day. I have a peak in the morning between 4 and 7 when the two geysers come on.

I have 4.3kw (name plate capacity) of panels, which on an average sunny day gives me about 20 kwh per day, and a cloudy day about 12kwh. A really rainy day gives me 5-6kwh.

I have one 5.5kwh battery (Hubble AM2) which cushions the production and load during the day. I dump excess power to to the geyers during the day and so the water is hot for the early evening showers.

Because I have only one battery, I save the battery at 90% charge until midnight in case of a power failure. After midnight it slowly drains to 25% until around 5am. Then the sun comes up and by around 9.00 am I am producing 2.5kw.

The inverter comfortably handles the load and is more than sized for my needs.

I could do with another 4.3kw of panels and another 1 battery in the short term (3 total in long term). This will more or less free me from the grid for 85% of the year (not totally on cloudy days). I am based in JHB.
 
Plan is to go largely off-grid for the apartment and later the main house too. (I rent the apartment). The wiring on the property is weird, we can't quite figure out why the consumption is so high.

Rough idea is to get 1x 8kW Sunsynk inverter + 1 x 5.5 kW Hubble battery. Amount of solar panels I'm unsure about at this stage.

And the of course to find a good installer that'll be able to offer services here.
 
Crusader said:
Plan is to go largely off-grid for the apartment and later the main house too. (I rent the apartment). The wiring on the property is weird, we can't quite figure out why the consumption is so high.

Rough idea is to get 1x 8kW Sunsynk inverter + 1 x 5.5 kW Hubble battery. Amount of solar panels I'm unsure about at this stage.

And the of course to find a good installer that'll be able to offer services here.
Click to expand...
Maybe get a quote from Steve at powerforum store. He also has a list of installers to recommend. Otherwise, go to the Sunsynk approved installers page and have a look if there is someone close to you that can quote you on installation or installation and supply of the products.
 
Before you do anything, reduce your current consumption.

Your current consumption is likely mostly hot water, heating, and cooking.

Reduce that, as thats the cheapest thing to do.
Then, and only then look at Solar.


For the single phase question - yes, you should be able to, however, you will need to look at rewiring the db, and will possibly need to change out any 3 phase equipment you have (motors, ovens). You can use a vfd or similar to drive 3 phase motors from single phase.
 
You should really look at a Growatt SPF5000ES 5kw inverter, they can be linked 6 times to make 30kw. And they are only R11,500 for the inverter. (very good reviews, all in one charge controller, hybrid etc etc) Then just add panels for now, so at least during the day you're getting free electricity and at night you use Eskom (or if you go over what your inverter can supply during the day)

  • Get a solar geyser (as in direct from the sun with those glass tubes on the outside of your roof) a geyser is like 60% of ones power consumption.

  • Invertor aircons etc, those old ones aren't efficient. Check the energy star rating on all your appliances.

  • Gas stove, electric oven is fine as a gas one is a pain and finicky. All lights on the property LEDs.

At a later stage add the expensive lithium batteries. If you have a power failure that drags into the night, then just invest in a little battery backup to power the TV and chill for a few hours before bed.

With regards to your 3 phases, you can measure your power consumption on each phase to see what phase is using the most electricity.
 
I should add that there are 3 phase hybrid inverters now, so you can go that route, if its not feasible pricewise to rewire your db.

I talk about 3 phase here a little if you're interested - https://goingsolar.co.za/2013/11/06/three-phase/

My first install was a 3 phase grid tied inverter that I made offgrid with 3 x Victron Multiplus and some batteries. Things have come a long way since then, and you can now get off the shelf equipment that does what I had to jerry-rig with multiple things!
 
Also - ignore anyone telling you to buy XXX.

First, you need to identify what your usage is.
Thats your first step.

Second step
Reduce usage, as this is the cheapest thing to do.

Third Step
Solar..

It may take a couple of weeks or even months to get step 1 and 2 done, but then you're in a better position for step 3.
 
Good morning everyone, need some advice please.

My current consumption is 25kWh a day.

I have PV geyserwise and a full gas stove and oven. Also 90% led lights.

I am getting my Sunsynk 8kw inverter today with a Sunsynk 5.12kWh lithium battery and 6 Canadian Solar 455W panels. (only had 6 in stock but wil add more later)

I can fit 10 panels on the one roof and I would like to ask what the best configuration would be?
2 strings of 5 then combined in parallel?
If this is the best way, I will only have one DC cable to connect to the one mppton the inverter.
Or should I have 1 string of 5 in series into each of the 2 mppt.

Your expert advice is appreciated.

Thank you
 
Steijn1 said:
Good morning everyone, need some advice please.

My current consumption is 25kWh a day.

I have PV geyserwise and a full gas stove and oven. Also 90% led lights.

I am getting my Sunsynk 8kw inverter today with a Sunsynk 5.12kWh lithium battery and 6 Canadian Solar 455W panels. (only had 6 in stock but wil add more later)

I can fit 10 panels on the one roof and I would like to ask what the best configuration would be?
2 strings of 5 then combined in parallel?
If this is the best way, I will only have one DC cable to connect to the one mppton the inverter.
Or should I have 1 string of 5 in series into each of the 2 mppt.

Your expert advice is appreciated.

Thank you
Click to expand...
Either way can work, as long as you are within the mppt voltage range of the inverter. If it was me I would use both MPPTs, current just works better when it's split into smaller branches.
 
Steijn1 said:
Good morning everyone, need some advice please.

My current consumption is 25kWh a day.

I have PV geyserwise and a full gas stove and oven. Also 90% led lights.

I am getting my Sunsynk 8kw inverter today with a Sunsynk 5.12kWh lithium battery and 6 Canadian Solar 455W panels. (only had 6 in stock but wil add more later)

I can fit 10 panels on the one roof and I would like to ask what the best configuration would be?
2 strings of 5 then combined in parallel?
If this is the best way, I will only have one DC cable to connect to the one mppton the inverter.
Or should I have 1 string of 5 in series into each of the 2 mppt.

Your expert advice is appreciated.

Thank you
Click to expand...
From where did you get the Sunsynk battery? And how much if i may ask?
 
TheChamp said:
Either way can work, as long as you are within the mppt voltage range of the inverter. If it was me I would use both MPPTs, current just works better when it's split into smaller branches.
Click to expand...
Thanks
 
Steijn1 said:
Good morning everyone, need some advice please.

My current consumption is 25kWh a day.

I have PV geyserwise and a full gas stove and oven. Also 90% led lights.

I am getting my Sunsynk 8kw inverter today with a Sunsynk 5.12kWh lithium battery and 6 Canadian Solar 455W panels. (only had 6 in stock but wil add more later)

I can fit 10 panels on the one roof and I would like to ask what the best configuration would be?
2 strings of 5 then combined in parallel?
If this is the best way, I will only have one DC cable to connect to the one mppton the inverter.
Or should I have 1 string of 5 in series into each of the 2 mppt.

Your expert advice is appreciated.

Thank you
Click to expand...
I would have said, if you have limited roof space to go with a higher watt panel - in your circumstances, going with a 550w or higher mono perc bifacial makes more sense.


For string values - the Sunsynk 8k likes around 380v-400v a string - thats the sweet spot for efficiency on that inverter. I probably need to re-read the manual again, but thats what I remember from last time I read it.

What are your panel voltages?

If you can only put 10, its probably going to be 5x2, which is a little low for that inverter.
10 x 1 won't be doable if the voltage is too high.

Let me know your OC voltage (open circuit) and panel voltage.
 
Steijn1 said:
Good morning everyone, need some advice please.

My current consumption is 25kWh a day.

I have PV geyserwise and a full gas stove and oven. Also 90% led lights.

I am getting my Sunsynk 8kw inverter today with a Sunsynk 5.12kWh lithium battery and 6 Canadian Solar 455W panels. (only had 6 in stock but will add more later)

I can fit 10 panels on the one roof and I would like to ask what the best configuration would be?
2 strings of 5 then combined in parallel?
If this is the best way, I will only have one DC cable to connect to the one mppton the inverter.
Or should I have 1 string of 5 in series into each of the 2 mppt.

Your expert advice is appreciated.

Thank you
Click to expand...
With the Sunsynk you will need to balance the two MPPTs as per Keith Gough (Sunsynk CEO and chief techie). To achieve an optimal arrangement with only six panels is going to be very difficult, if not impossible. You ideally want a higher voltage on your strings to kickstart the MPPTs as early as possible in the mornings, and stop as late as possible in the evenings, so closest to 400V as possible. The Sunsynk's MPPT range is 125-425V, so it will only start producing power when the panels are giving at least 125V. You did not give the exact specs of the CS panels that you selected, so its difficult to say, but looking at some other CS panels, they appear to produce around 48.8V open circuit, but only 40.9V under full load (load drops the voltage). 3 in series on each MPPT will therefore initially produce 146.7V, but as soon as the inverter "combs" the load across to draw from solar, the voltage will drop to 122.7V, and cause the solar load to be "combed" back. So the MPPT will probably flap up and down, and the inverter too.

Obviously this needs to be verified with the exact model of panel that you have (mind posting it?), but not a situation that I would want to endorse. Did the person who sold you this explain it to you? You may want to consider returning the panels in favour of some panels that they do have sufficient stock of, to at least allow for a working system while you wait for the balance. I know that panels are difficult to get right now, and there is some price-gouging, but I would rather source equipment from a reputable source that knows and understand what they are selling, what the limitations are, and who can advise you on such caveats.
 
itareanlnotani said:
I would have said, if you have limited roof space to go with a higher watt panel - in your circumstances, going with a 550w or higher mono perc bifacial makes more sense.


For string values - the Sunsynk 8k likes around 380v-400v a string - thats the sweet spot for efficiency on that inverter. I probably need to re-read the manual again, but thats what I remember from last time I read it.

What are your panel voltages?

If you can only put 10, its probably going to be 5x2, which is a little low for that inverter.
10 x 1 won't be doable if the voltage is too high.

Let me know your OC voltage (open circuit) and panel voltage.
Click to expand...

Hi,

The panels are 49.3 Voc and 41.3 Vmp per panel, so yes I don't want to do 10 in series. Want to stay below 450V.
The Imp is 11A

I will add another 10 panels (if I can fit them on the other roof) later to have 9100W in total.

Thank you
 
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