Hi guys,

I am new to this....I am using approx 550kw a month in electricity, and would like to get a battery and inverter solution that can be upgraded going forward with additional battery and also solar panels.

There are two units on the property (flat and main house) and we are all energy conscious already. We have already got a gas geyser in flat and also solar geyser on main hosue, so dont use any electricity there, except for a rare time when the water is too cold for a shower on the solar geyser, and we use Eskom to heat it for 30min. This is very rare...

We have a gas stove and oven in the flat, and in the main house we have gas stove and electric oven...the oven is rarely used, maybe once every 2 weeks.

Our main usage I think comes from the 1 electric kettle used 2 per day, 2 fridges, 2 microwaves, 2 washing machines (each run once per week), and a pool pump. I pay one electricity bill which is for the total electricity used on the property. Most months its around 550kw for the month, sometimes less. I think we are single phase, not sure how to tell, but the DB board looks like a regular one, nothing special about it.

During load shedding I have made use of our 7kva generator, which seems to run everything OK, but then again, I have not tried to use the oven or washing machine during that time period. I have run the pool pump with tv's, lights etc, and all is fine. We make a point of not even attempting to run the oven or washing machine while on generator and I expect we will do the same when on a battery solution.

I would like to start by just getting an inverter and battery, and then upgrading as we move forward. Would it be better to get an 8kv inverter so that its easier to upgrade in the future? Does the 5kv inverter mean that the total electricity that can be drawn at one time is 5kv? Someone told me that I can get a 5kv inverter and battery, and then get a second or third 5kv battery in the future, but I am not sure if that is the right way to do it.

I would like to be able to keep the property running for long periods when there is 4 or even 6 hours of load shedding....

I would like to add solar panels in the future, we have roof space, but am told that the old asbestos roof that they could go onto would need to be replaced first, as nobody will install panels onto that kind of roof. This would be a huge expense, so would like to start first with battery and inverter. Is it true that nobody will mount onto asbestos roofing?

I was looking at trying to get a sunsynk inverter and freedom won battery as I am told its a good combination. So is it better to start with a 5kv inverter and 5kv battery, or go straight to a 8kv inverter and a 5kv battery then add another 5kv battery later?

A lot of this stuff is confusing for me, so I am really trying to choose the right options...I do have finances to purchase, but I dont want to have unnecessary expenses or waste money when I could have done things differently from the start.

I am in the Garden route (Sedgefield), so also looking for a good supplier and installation company locally. I spoke to one gentleman who said that I must just go direct for a 10kv battery and inverter from the start, but he didnt even know what my usage is or anything....he just saw the property and probably thought it was high and we have money to spend....but I am not sure. I dont want to be ripped off, or pay for something way bigger than we need.

Ideally I would like to one day be off grid, but the guy here told me that I would still need to pay eskom 1k monthly, so I think its not really worth it since the bill is not much more monthly anyway.

Any advice for me would be appreciated. Thank you kindly.

 

 

 

Having lots of questions is the best way to learn 🙂 it great that you are already energy-wise and luckily your bill isn't that great

Inverter

If you can afford it id say go straight to the 8kw upfront - it gives you some headroom and even if you don't use it right away there will be a time when you need that extra power - especially with 2 buildings / households. If you got a 5kw you'd have to play minister of energy and decide which appliances are run when quite strictly - and this can be tricky across 2 abodes. 

If you don't mind the added overhead of managing household 1 and 2 (maybe use some smart switches and automation) then a 5kw could work. We have a 5kw and started with 1 battery - eventually upgraded to 2 - but we are short on the inverter side. During loadshedding people forget (because there is power) and run the microwave + dishwasher + washing machine at the same time = AC overload. 3 main bands according to budget and functionality Axpert/Voltronics (Kodak, Luxpower, Axperts), Sunsynk/Deye and then Victron / Fronius. Its dependent on your requirements (3-way blending / grid feed-in etc) and budget which one you will settle for. Some of these also allow you to add your current generator as a 4th source of power - allowing you to charge the battery when PV is low and eskom is...well...eskom

Batteries

Always a good idea to match inverter + battery as mixing batteries is not often possible. Since you wont have panels initially I'd go for 2 batteries to give you 9.6 or 10.2 kWh - that should get the home through 4 or 6 hours of shedding. Also look for an Inverter + Battery combo that can communicate so that the 2 are kept in synch in terms of when to charge and discharge and what rates to use - this is achieved through CAN or RS485. Notable brands include - Sunynk, Dyness, Pylontech, Greenrich, FreedomWon and the newer Hubbles. Lithium batteries are easy to add on to so starting with 1 is not a bad thing

Panels

Always good to go fir as high wattage as you can get so that you need fewer. The 8kw Sunsynk for example can take up to 10.4kw of panels which is a lot and more than enough to cover your loads + charge batteries

Random question - would you still need to pay eskom if you go onto prepaid? 

Edited December 22, 20222 yr by mzezman

https://www.moneyweb.co.za/news/south-africa/no-more-solar-pv-on-asbestos-roofs-says-labour-department/

Asbestos apparently being blocked, but to be checked.

If solar is not an option, you couldn't have full benefit of a Sunsynk. Might be worth considering just getting a simpler battery inverter. But for 2 households, 8-10kW plus is indeed better.

45 minutes ago, mzezman said:

go straight to the 8kw upfront -

Yeah, sad but pure truth, anything lower and you must babysit your system, something that irritates me to no ends.  

51 minutes ago, mzezman said:

Always a good idea to match inverter + battery

Ooh, thanks, another piece of truth. The worst failures iv seen the last year is people matching a 5kw battery with 8kw inverter. The amount of times the battery goes into surge protection is show stopping. 

If you cant afford anything above 5kw battery, then stay with 5kw invertet. 

 

If you want to start in a modular way then start with a 5kw inverter and a 1c rated 5kw battery.Make sure the inverter can run in parallel with another.

You can always add another inverter and battery later.

We used approx 650kWh per month.

We dont use gas. Everything is electrical ie. 2 electric geysers, 3 aircons, electric oven and electric stove.My wife runs a hair salon from home and use some power hungry salon equipment ie. Hairdryers, curling and straightening irons etc ..

 

The system Literally carries the whole load.

 

Our system consist of

8kw sunsynk inverter 

3x 5kwh batteries

14x 545w canadian solar panels 

 

Currently our eskom usage sits at R76 pm or less.

 

 

 

 

 

 

 

 

 

 

 

 

You won't have problems finding installers to install on Asbestos, I've recently had mine done just over 1 month ago and I am located in George, and all the quotes I got at the time, not 1 single installer had any problems installing on Asbestos, they would just use the safety requirements like using proper mask etc. 

Look at High Cell Solar Solutions, they did mine and very recommended, great installer! they also on the Installer Approved list with Sunsynk, so you can get their info on their website.

I went with 5kw Sunsynk Inverter, 2x 5kw Sunsynk Battries and then 12x 425w Trina Solar Panels and works amazing.

Edited December 22, 20222 yr by William ZA

3 hours ago, BritishRacingGreen said:

Yeah, sad but pure truth, anything lower and you must babysit your system, something that irritates me to no ends.  

The fact that we haven't been babysitting our electricity is exactly why we're in the position we're in. I believe (quite strongly) that if you're going to the expense of solarising your property, solarise you lifestyle first. Do you really need your water temperature set at 65C? Do you really need to put your dishwasher and washing machine on at the same time? I've just installed a 5kw system, and I'm wondering what to do with it all. As I'm sitting here typing this on my laptop my house is using 250 watts.

(BTW I used to have a MGBGT in BRG  )

18 hours ago, Solar noob said:

I am in the Garden route (Sedgefield), so also looking for a good supplier and installation company locally. I spoke to one gentleman who said that I must just go direct for a 10kv battery and inverter from the start, but he didnt even know what my usage is or anything....he just saw the property and probably thought it was high and we have money to spend....but I am not sure. I dont want to be ripped off, or pay for something way bigger than we need.

10kwh of battery does cost more, but you can do more with it. I easily get right through the night on 10kwh. Now I could on 5, but I'd have very little left in the tank in the morning, so if there's loadshedding at 6 and overcast weather, I might be stretched. 

EG. At 6am I typically have about 70%/7kwh  remaining. That's an effective 6kwh because the battery will shut down when it has 10% left. 

On a 5kwh battery I'd have 20% left, effectively 1.5kwh.

Also, since I have a 1c battery, it can take higher loads at any given time. 

18 hours ago, Solar noob said:

Ideally I would like to one day be off grid, but the guy here told me that I would still need to pay eskom 1k monthly, so I think its not really worth it since the bill is not much more monthly anyway.

That depends on the tariff you are on. Some tariffs are a flat fee for the connection & acct mgmt. Some, usually prepaid, have no flat fee but a higher charge per kwh. So check what tariff you're on and what it will cost to switch. 

I switched from the default tariff to prepaid in Johannesburg some years ago. If I'd done nothing else, I'd have saved a tidy sum by now. 

18 hours ago, Solar noob said:

Any advice for me would be appreciated. Thank you kindly.

Don't just buy an inverter and a battery. Buy an inverter and battery that are a good combination. 

EG. I originally had Revovs with  a Goodwe inverter. You don't get proper comms with this combination, and Revov really only guarantee compatibility with Victron & Sunsynk. This combination was always a little unstable. 

Eventually I took a deep breath & installed a Freedom Won battery. Bingo! This gets on quite happily with the Goodwe. The CAN bus comms between the battery & inverter work, and the system is more stable. Also the battery can now control the BMS and thus gets what it needs. 

Also, no system involving Solar delivers to full potential without us changing our habits. Learn to make hay while the sun shines. EG Don't run the dishwasher at night. 

Get the whole household on side with this. I know this sounds a bit rude, but people tend to think "free & unlimited" when they hear solar. It isn't unlimited, and in the interests of keeping the essentials powered up, you need to learn to live within its limits. 

One last piece of advice for now 🙂 Don't use "solar noob" as a screen name. In a couple of year's time you'll be the ou man of solar, dispensing advice to others.

Thanks everyone so far for all the help.

We are not on pre-paid electricity, and pay the municipality based on our monthly consumption.

I was told that if you have solar in order to get off grid, you will still need to pay eskom R1000  a month anyway....not sure if that is even true. I think we pay around R300 odd to Eskom flat fee, even if we dont use any electricity.

I see on my bill it says "Domestic 60A", and on the sunsynk inverter description it says "Max. Continuous Charging Current 50A". Does that mean it will not work with my house if I have 60A?

Considering that we all use electricity sparingly and are not going to be adding more power hungry equipment any time soon, I am thinking of just starting with a 5kw inverter and one sunsynk 5kw battery. If I can get around the asbestos roofing, then I would like to add solar panels to that.

33 minutes ago, Solar noob said:

Thanks everyone so far for all the help.

We are not on pre-paid electricity, and pay the municipality based on our monthly consumption.

I was told that if you have solar in order to get off grid, you will still need to pay eskom R1000  a month anyway....not sure if that is even true. I think we pay around R300 odd to Eskom flat fee, even if we dont use any electricity.

In my part of the world, people talk about an Eskom stealth tax on solar power users. There isn't such a thing, but there do seem to be a couple of things that could be incorrectly interpreted and thus sow that idea in a person's head.

1) The people complaining have not really looked at their municipal account beyond the bottom line (in my experience, this is not uncommon). So they never noticed (I'm taking Johannesburg here) that their bill had a fixed component every month (about R700) and then they were billed per kw/h used. So they go solar, their useage drops, but the flat fee remains. So suddenly they see they are STILL getting billed for electricity, and how can that be? Well it must be those sneaky swine at Eskom. But how does Eskom (or the city) even know that you have panels?
2) Some municipalities (and maybe Eskom itself, where they supply directly) require solar users to switch to a reseller's tariff which allows them to get a credit for surplus power they export. Certainly such a tariff is available in Johannesburg, but, as with the regular post-paid tariff, it has a fixed component a month because now the supplier has to do actual management of the account. 

In all cases, the flat fees are party to cover the admin side of things (this goes away with pre-paid because if you don't pay, the meter cuts you off), and partly for the cost of supplying a connection to the grid. Certainly in Johannesburg the City is very keen that pre-paid users should be paying some sort of flat fee a month because the City still bears the cost of providing you with a grid connection.

I switched from the default post-paid to pre-paid some years ago. This is in Johannesburg, with City Power being the supplier. There were costs to switching, but these were soon recovered, and I started saving a useful amount of money each month and if I'd done nothing else I'd have saved a tidy sum by now. I think this is as it should be. If I pay the City (or anybody else) in advance for stuff I have yet to consume, that there is good for their cash flow and they should give a consideration for that, because they want more consumers to do that so that their cash flow improves further.

3 hours ago, Solar noob said:

I see on my bill it says "Domestic 60A", and on the sunsynk inverter description it says "Max. Continuous Charging Current 50A". Does that mean it will not work with my house if I have 60A?

That is comparing apples with apple juice. Your bill refers to alternating current at around 230V supplied by Eskom to your main circuit breaker, and the Sunsynk charging output current refers to direct current at around 48V at the point of going into the battery.

38 minutes ago, GreenFields said:

That is comparing apples with apple juice. Your bill refers to alternating current at around 230V supplied by Eskom to your main circuit breaker, and the Sunsynk charging output current refers to direct current at around 48V at the point of going into the battery.

So if I wait before getting solar panels, and just get the battery and inverter and panels later, the battery will need to be charged by Eskom.

Will the Sunsynk inverter + battery setup be OK getting charged by 60A?

23 minutes ago, Solar noob said:

So if I wait before getting solar panels, and just get the battery and inverter and panels later, the battery will need to be charged by Eskom.

Will the Sunsynk inverter + battery setup be OK getting charged by 60A?

The charging amps for the battery are set  on the inverter according to the battery manufacturers recommendations. 

Edited December 23, 20222 yr by TiaanSmit

5 hours ago, Superfly said:

Posted here incorrectly but can't delete a wrong post?

Hi there. 

Can I help?

Jay

On 2022/12/22 at 9:04 PM, BritishRacingGreen said:

Ooh, thanks, another piece of truth. The worst failures iv seen the last year is people matching a 5kw battery with 8kw inverter. The amount of times the battery goes into surge protection is show stopping. 

If you cant afford anything above 5kw battery, then stay with 5kw invertet. 

With the correct setting on the inverter, this should not be an issue at all. Then when adding an extra battery later, the inverter settings can just be adjusted.
Less things to upgrade especially compared to a parallel installation.

One other main benefit of having a bigger inverter is that it does not run on maximum very often / all the time thereby extending the inverter longevity.
Almost like having a small 1.4L Citi golf and try driving at 120km/h compared to an Alfa 2.5L (yes, one of those) driving at the same speed.
The Citi Golf has to work hard to get to the 120km/h and the Alfa is just idling ... 😃

34 minutes ago, DeonBez said:

With the correct setting on the inverter, this should not be an issue at all.

I assume you are referring to some inverters that allows  Max Battery Discharge setting. Well  this will  :

1. Not be fast enough to sense a sudden surge from say 4kw to 7kw load while the is in pure battery mode. The instaneous surge is drawn from the battery  and we have field results that some battery bms protects in a very short period, e. g. Livoltek. 

2. Secondly, if the BMS does pass the initial surge,  the inverter will sense the max discharge thresshold, raises an error and closes shop. This is of course during loadshedding at night  where there is no other source than battery. 

 

So I state again, it is imperative that one match the battey to the max requirement of the inverter. 

Edited December 24, 20222 yr by BritishRacingGreen

54 minutes ago, DeonBez said:

One other main benefit of having a bigger inverter is that it does not run on maximum very often

That is true, but it can and will go to its max if the load demands. But with an inadequate dc source connected to it, it can and will fail. 

@Steve87  will be able to tell you about field experience in this regard. 

 

 

@BritishRacingGreen, agreed, but it is all part of the correct design for what the user/client require.
And yes, field experience is very valuable for this.

We have been using solar since 2014 in mainly off-grid and sometimes grid assisted mode.
In our case the inverter was the limiting factor but the inverter (SMA) and the battery (no promotion here) could handle power surges well.
Changeover control from off-grid to on-grid was done by Raspberry Pi external to inverter and battery.
Only once had the situation as described occurred where the battery shut down and this was due to an error in the connection/comms between the Pi controller and the changeover switch.

On 2022/12/23 at 3:10 PM, Solar noob said:

So if I wait before getting solar panels, and just get the battery and inverter and panels later, the battery will need to be charged by Eskom.

Will the Sunsynk inverter + battery setup be OK getting charged by 60A?

60A is the limit your municipality applies. You have a 60A municipal breaker and your house can never draw more than 60A from the grid.

It is an upper limit. If you draw less than 60A (which you will, most of the time) then that's fine. If you draw more then the main breaker will trip.

It has nothing to do with the rate at which your in inverter charges the battery.