Jump to content

So many "professionals", so many options, so many opinions - no clue who to trust on what to install


Nicholas Baard

Recommended Posts

Would appreciate any advice as I am clueless.

I have a solar geyser and gas stove so have very little power consumption, average daily consumption 14KWH, with peak of 4.2KW draw and average during the day of 0.8kw per hour and at night 0.4Kw per hour.

I have three phase power for no reason at all but its there.

I want to install a 5KW Inverter, with 5.1KW lithium battery and 6/8 panels as a backup for loadshedding and to reduce my Eskom usage and cost.

My questions are this:

Do I need to go with a Deye or Sunsynk Inverter rather than Growatt or Kodak?

Can my DB be bridged to use a single phase inverter on 3 phase power or do I have to go BIG with a 3 phase inverter?

Which brands of battery are recommended? Hubble, LifePO4 Shoto, FreedomWon, Dyness

Which brands of panels are recommended? CSUN, Longi MonoPerc, Haitai, Canadian Solar

Many thanks

Link to comment
Share on other sites

@Nicholas Baardmy humble opinion is based on my personal experience with my growatt sff5000es and dyness powerbox. 

Since you have a Gas stove and a solar geyser you have no loads before the inverter. That means you won't need a true hybrid like the deye/sunsynk. If you would like help out by feeding in to the national grid then the sunsynk is in first place.

The reason for the pairing of growatt and dyness is that they communicate very well via the CAN port.

Since you don't need 3 phase you should get it changed to single phase to reduce your connection fees.

Honestly any axpert type inverter would be fine for your requirements. It's up to your budget and ability to recognize FOMO.

Link to comment
Share on other sites

Okay so the problem with most of the kodak range can be seen as in this video. 

This is true for any inverter labled off grid. 

 

In terms of cost and performance many people find that sunsynk is the best place to be. I have a victron system and as much as I love it i do have to admit the sunsynk is a very compelling system as it offers nearly all of the victron functionality that i use at a much lower price. 

 

You dont need a 3 phase inverter, just move all loads onto one phase. 

 

Panel brands, i have experience with canadian solar and JA solar. See what the market has to offer. I trust both those brands.

 

As for batteries, make sure they have compatible coms with the inverter you chose, i have pylons, have experience with FreedomWon and Bluenova also many people on the forum who are happy with the Hubbles

 

Edit: I am by no means an expert on the axpert inverters, many happy people who use and install them maybe @87 Dreamcan help you out with deciding what voltronix inverter suits your needs. 

Edited by Basil Katakuzinos
Link to comment
Share on other sites

Yes, the video was made in 2017 and 100% correct at the time. I had 2x5kW Axpert inverters in parallel. I hammered those inverters and never had a problem with them. The biggest disadvantage of those inverters at that time was that when running on solar power, the mixing of power came from the batteries. My batteries were very confused, they never knew if they were charging or discharging. The battery power chart looked like a lie detector test spiking up and down the whole day. I am not sure it did the batteries any good. After about 2 years use, there was a marked reduction in my battery capacity. 

In the latest models, power mixing makes use of grid power, if available, and not the batteries. That to me is a huge improvement. Now the batteries are only used as backup power once no grid power is available. The one disadvantage still exists that power only moves in one direction. Your load on the the dedicated circuit for the inverter might be low and you have load on your grid circuit, but you cannot feed them. 

Sizing of solar panels array becomes a problem, especially if you are not sure of how much power you consume on average during the day. Oversizing of solar panels becomes a waste, as half the panels do nothing as the inverter will cut down to what is required according to your load. No matter how many solar panels you install, they will never be the right amount. At times you will have too many and at times you will have too little. 

Link to comment
Share on other sites

5 hours ago, 87 Dream said:

You overload the Axpert with loads or Essential Loads.

Thank you  @87 Dream At my previous house, I had the whole house on essential load and I had to manage the loads manually. I have a long haired power guzzler in the house. I can see on my power meter when she wakes up and start moving around, especially when entering the kitchen. It eventually became a fulltime job to balance everything. So this time round setting up my second solar system, I decided to split the high demand stuff from the essential loads as I don't have the time or not always home when the energy demand goes through the roof. 

5 hours ago, 87 Dream said:

So you use a smart switch (TomZn smart breaker / CBI Astute) to turn the geyser on when the battery is fully charged & there are no heavy loads.

That is exactly what I was looking for. Now I can automate the high energy items, depending on load and time of day.

6 hours ago, 87 Dream said:

Especially on the 7.2kW MAX with some room to play with capacity wise, this is a very hard solution to beat for the money dished out to acquire. 

I agree 100%.  

Link to comment
Share on other sites

@87 Dream, a question you can answer, with all these different re-branded Axperts, for warranty and repair services, which brand or brands are the best/easiest , I have used Victron and Sunsynk, but now am the go to person in my circle of friends/relatives due to load shedding, and not everybody wants to spend too much money, so thinking of Axperts.

Link to comment
Share on other sites

16 hours ago, Nicholas Baard said:

I want to install a 5KW Inverter, with 5.1KW lithium battery and 6/8 panels as a backup for loadshedding and to reduce my Eskom usage and cost.

I agree with most of the comments. But 5kWh battery is definitely too few. Battery capacity is the key element for a reliably working solar system. I upgraded to 19kWh with 2 Axpert/Synerji MKS 5K inverters in parallel. Reed my recent posts in the "Inverter" forum. Axperts/Synerji (and other Voltronic rebrands) have the undocumented feature of automatic inverter neutral to earth bonding while in isolated solar/battery mode.

Yes you should get rid of the 3 phase and convert to single phase. The wiring change is rather simple, just bridge the 3 phases together at the DB input, using only one phase + neutral from the incoming cable. But you must do this with your utility provider. They will also have to change the meter.

Link to comment
Share on other sites

@87 Dream, most of these people that I am talking about are looking in the price range of the small inverters from 1.5 kW to 3 kW, and using it as a ups, i am looking to hook them up to the Hubble S-100 batteries, my question was out of all the Axpert brands, which have you found the best for ease of warranty/out of warranty repairs.

Link to comment
Share on other sites

32 minutes ago, 87 Dream said:

Let me stress they must have the high solar PV input of 450V to be an original machine. The ones with the 145V input are not capable to blend power.

I definitely do not agree with that. On the Axpert promotional data sheet is only one model with 450V PV OCV ability, the MKS II 5K. And Coulumb decommands it. It is perfectly practicable to connect several PV panels in series and parallel in such a way not to exceed the 115V operational and 145V OCV allowed. All these models do perfectly mix and manage solar with battery power with the right setting.

Edited by Beat
Link to comment
Share on other sites

18 minutes ago, 87 Dream said:

See the models and stats. I bet your model cannot run without a battery...This is the dead give away. The only unit I know that can still blend & is the smaller PV input is the KING. 

That is true but a solar system without battery does not make sense in view of overcoming load shedding. In contrary, the battery is the key element for the aim to become an as much as possible from grid independent system. Have you ever seen a UPS without battery?

Edited by Beat
Link to comment
Share on other sites

6 hours ago, Beat said:

All these models do perfectly mix and manage solar with battery power with the right setting.

Yes, they do. Why do you want to blend/mix solar with battery power? If it is a cloudy day, your batteries take a hammering and when the sun sets, you charge your batteries with grid power. That defeats the whole object of having solar power. That does not make sense. Batteries should only be utilised for load shedding, not supply power during the day when there is insufficient solar power. Rather get a unit that can mix with grid power during the day. I had the 145V system before, never again. That system killed my batteries within 2 years. 

Edited by Don
Link to comment
Share on other sites

6 hours ago, Beat said:

I definitely do not agree with that. On the Axpert promotional data sheet is only one model with 450V PV OCV ability, the MKS II 5K. And Coulumb decommands it. It is perfectly practicable to connect several PV panels in series and parallel in such a way not to exceed the 115V operational and 145V OCV allowed. All these models do perfectly mix and manage solar with battery power with the right setting.

Hi @Beat what does 'decommands' means ? It sounds so horrifically final.

Link to comment
Share on other sites

5 hours ago, dropkick said:

what does 'decommands' means ? It sounds so horrifically final.

Sorry, I might get mixed up with my French knowledge. I wanted to say "does nod recommend".

5 hours ago, Don said:

Why do you want to blend/mix solar with battery power? If it is a cloudy day, your batteries take a hammering and when the sun sets, you charge your batteries with grid power.

Well, my aim is to harvest as much as possible solar energy during the day and use it at night, in order to consume as few grid power as possible. I recharge from grid only when battery SOC gets below 20% at night.

Link to comment
Share on other sites

18 hours ago, 87 Dream said:

Let me stress they must have the high solar PV input of 450V to be an original machine.

No, there are 145 V max PV original Voltronics models about; the King, an MKS 58.4 V, and an MKS 64 V. I have no idea how easy it is to obtain these in any particular market.

Quote

The ones with the 145V input are not capable to blend power.

They all blend battery and PV power just fine. So I assume you are talking about utility power with PV/battery power. It's true that most of the 145 V max PV models can't do this; the exception being the King. Even the 450 V and 500 V models have to be in a particular output priority mode (SUB) to blend utility with battery/PV power.

18 hours ago, Beat said:

On the Axpert promotional data sheet is only one model with 450V PV OCV ability, the MKS II 5K.

No, there are plenty more: MKS III and IV, VM III, Max, etc. An earlier post listed many of them. Some of those are 500 V max PV, but I'll limp them together as "higher voltage SCC" models. This seems to be the direction that Voltronic are going with most new models. There is even a higher voltage SCC version of the King (Axpert King II) now.

Quote

And Coulumb decommands it.

I'm not fond of these models, especially with the problems some users have had with wet panels causing the bus voltage to rise and trip the inverter with a fault code. Also, the PV inputs are lethal even with no panels connected. Plus, I have no experience with them. Their legality in many jurisdictions is questionable. I think that many users get away with using them because they are not the most common inverter type, so they tend to get overlooked. Ironically, the blending of utility and battery/PV power makes them more or less the same as hybrid inverters, but with "off grid" written on the side, so they avoid a lot of the certification requirements.

But I can see why they are popular.

Link to comment
Share on other sites

Interesting discussion, but I am convinced that the OP is now more confused than ever 😀

So @Nicholas Baard, as others have suggested, reducing monthly cost would start with requesting the municipality to convert your home to single phase. Your utilisation (14kWh/day) simply does not justify it, and unless you have specific use-cases for it (like an industrial oven, dough mixer or other industrial equipment).  

I have slightly less utilisation than you (10-12 kWh/d), and similar evening base loads (400W), and over 1 year ago I went the 5.5K Sunsynk route. I was (and still am) amazed at its flexibility. I have everything on essential loads, but it's great to know that if my needs expand, I can put some loads before the inverter, and I might just have to do that when my heatpump becomes obselete. The Aux port is also bi-directional and therefore flexible for smart loads or inputs such as a genny or even microinverters. There is not need to constantly fiddle with it and "tune" it, it just works, and I haven't regretted my decision yet. Being a mid-range solution, it's arguably a little more expensive than the traditional axpert types, but well worth it, and great value feature for feature when compared with the high-end kit, basically champagne on a beer budget.

On batteries, the ones that you have mentioned are mostly good. Hubble is excellent value right now, and a single AM-2 can charge and discharge at 1C, so it's perfect if you want to start small and build up a bank of them. I have heard good things about Freedom Won and Dyness, but they may require a larger investment upfront to perform similarly.

On panels, Canadian Solar, Longi or JA Solar are all excellent and come with good warranties.

Link to comment
Share on other sites

4 hours ago, Coulomb said:

I'm not fond of these models, especially with the problems some users have had with wet panels causing the bus voltage to rise and trip the inverter with a fault code. Also, the PV inputs are lethal even with no panels connected. Plus, I have no experience with them. Their legality in many jurisdictions is questionable. I think that many users get away with using them because they are not the most common inverter type, so they tend to get overlooked. Ironically, the blending of utility and battery/PV power makes them more or less the same as hybrid inverters, but with "off grid" written on the side, so they avoid a lot of the certification requirements.

But I can see why they are popular.

There might be some advantages. You can hook up to 10 panels in series, simplifying wiring and saving copper, as approx 10A max operating current can be handled with 2.5mm² wire. But there are disadvantages. Besides what Coulomb mentioned, if only one of the panels becomes faulty, the whole array in series will have no output. And troubleshooting becomes challenging. With smaller number in series, only the affected array would fail, the others in parallel continue to deliver.

Link to comment
Share on other sites

Hi All

@Nicholas Baard I hope you don't mind me giving my opinion on this discussion? 

I have a Goodwe ES4.6 and currently very happy with it performance. All inverter have their pros and cons so one would have to select the inverter depending on what you what to achieve taking into account what your wallet can afford. The reason I selected the unit I have is that it is one of the few inverter that the PV will supply Grid side when there is sufficient PV Power available. this function as far as I am concerned is advantages when it comes to saving on the electrical account there by reducing the payback period of the system. Or alternatively one can just get a bigger inverter that can drive all the loads but with this comes at a higher price as not only do you need a larger inverter but you will need more panels and battery to suit as you would be driving all the loads simultaneously .

I have a small setup currently (6x 455kw Canadian Solar Panels, one Pylontec US3000C battery and a Goodwe ES4.6 inverter) and I have already cut my electric bill by at least 75% and have had sufficient battery power for load shedding. 

My plan is to improve the system by adding battery's and PV Power till i don't need the grid at all.  This weekend I will be adding additional 1820 watts to the roof and will continue adding requirement till I have achieved the max my inverter can handle.

Initial I was really sold on the Deye/Sunsynk unit but was told that it can only supply PV power to The essential side of the inverter. I have still split my DB board with the essentials and heavy side but to me it made no sense when the cost saving in power is mostly on the Grid side of the inverter. 

If you looking for an inverter for a Back up system for when there is no grid available then the Deye/Sunsynk would work just fine.

It would be interesting if the guys in the know could comment on what inverters are available that have the ability to supply the excess PV power to the grid side of the inverter (Heavy Loads)

hope that helps

 

 

Link to comment
Share on other sites

28 minutes ago, Ronald W said:

It would be interesting if the guys in the know could comment on what inverters are available that have the ability to supply the excess PV power to the grid side of the inverter (Heavy Loads)

Hi Ronald, I have been out of this game for some time. The Infini inverters can do that. I am not sure of the latest technology available. 

Link to comment
Share on other sites

The Infini would basically run flat out harvesting the maximum amount of solar energy like any grid tie inverter and export the excess power to the heavy load side without cutting back if there is low load on the essential side of your system.  

Link to comment
Share on other sites

6 hours ago, Ronald W said:

Initial I was really sold on the Deye/Sunsynk unit but was told that it can only supply PV power to The essential side of the inverter. I have still split my DB board with the essentials and heavy side but to me it made no sense when the cost saving in power is mostly on the Grid side of the inverter. 

When I read the Sunsynk manual I had the impression that it could operate as a full grid-tie inverter, i.e. pushing PV power back to the non-essential side of things. Otherwise it would not be coming with a CT coil... so unless I am misunderstanding something I believe the Sunsynk inverter actually has the capability you want.

Link to comment
Share on other sites

6 hours ago, Ronald W said:

Initial I was really sold on the Deye/Sunsynk unit but was told that it can only supply PV power to The essential side of the inverter. I have still split my DB board with the essentials and heavy side but to me it made no sense when the cost saving in power is mostly on the Grid side of the inverter. 

Nothing could be further from the truth. The Sunsynk Hybrid Parity (Super) Inverter can and does supply excess PV power to loads before the grid, up to the provided CT coil.

 

  image.png.9c6ba62bd854f8043c7f6dd80befecce.png

Link to comment
Share on other sites

40 minutes ago, Sir Rodgers said:

When I read the Sunsynk manual I had the impression that it could operate as a full grid-tie inverter, i.e. pushing PV power back to the non-essential side of things.

The Sunsynk has a tick box option to select if you want to push back power to non-essential loads. My inverter is set to always receive 10Watt from the council to avoid feedback and then the excess solar power go to non essential, however this is as long as grid power is available. When there is load shedding only essentials are powered. Another nice function is the timer functions where you can set grid charging to keep your battery for example at 70% SOC from 22h00 to 24h00 and lets say at 50% from 24h00 to 03h00. In other words to get maximum use out of your battery you can stagger its SOC usage with the timer function to last till the morning. I don’t know if the other inverters can do this.

Link to comment
Share on other sites

8 hours ago, Sir Rodgers said:

When I read the Sunsynk manual I had the impression that it could operate as a full grid-tie inverter, i.e. pushing PV power back to the non-essential side of things. Otherwise it would not be coming with a CT coil... so unless I am misunderstanding something I believe the Sunsynk inverter actually has the capability you want.

You will really need to check that as I had the sales man from Ellies electronic confirm that it does not feed PV to the non-essential side. As the Sunsynk is a grid tied inverter it would be mandatory for it to have a CT coil to comply with many country's (Municipality) regulations on PV installations. secondly the inverter would require the CT coil so it can know what is happening with the grid. The inverter requires the coil to adjust the frequencies (HZ) so it can achieve the zero feed back setting on the inverter. lastly I'm sure the inverter would also require CT coil to correct the frequencies to the grid when selling power back to the grid.

If the Sunsynk inverter could supply power to both sides then its worth the money that you pay for the unit and I would have one on my wall and saved myself about 8K on my current inverter. 

Im sure there must be someone here that has the inverter installed and confirm this is true or not.

7 hours ago, Gerrie said:

The Sunsynk has a tick box option to select if you want to push back power to non-essential

If @Gerrie is correct and the then Sunsynk push the power to the Non-essential side FROM THE PV PANELS and not the grid then inverter is a good option. 

Link to comment
Share on other sites

37 minutes ago, Ronald W said:

I had the sales man from Ellies electronic confirm that it does not feed PV to the non-essential side.

When it comes to solar you need to speak to system designers and installers the sales people will sell you the the stuff they need to clear from their shelves.

Link to comment
Share on other sites

1 minute ago, Gerrie said:

When it comes to solar you need to speak to system designers and installers the sales people will sell you the the stuff they need to clear from their shelves.

Well the salesman lost out on the sale and I spend more money then I should of 😞 if that is the case.  But be that is it is Im happy with my current system.

 

 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...