Hey guys,

Been doing a lot of reading here - some brilliant advice and posts.

I'm looking at installing a hybrid system - around 4.5kW Inverter, 3.6kWp PV and probably 2 Pylontech 3000s, largely DIY.

So here's the question - what brand inverter?

Leaning towards the Goodwe as a brilliant little all-rounder. Seems to include all function we require in one unit, good quality, easy install, and all at a pretty reasonable price.

But what would we be missing out on compared to the competition? 

Thinking specifically Victron and/or SMA - what extra features and enhancements do these offer over the Goodwe? I hear the Goodwe is a little limited in the setup / programming one can do - this'd be a serious drawback for me. Are the others worth the extra expense and complexity? (As I understand both these other systems one would need seperate modular units as opposed to Goodwe all-in-one)

 

Would really appreciate your guys' reasons for preferring one over the other...

12 hours ago, markus_m2 said:

So here's the question - what brand inverter?

That's like asking a bunch of Afrikaans people at a braai of the Hilux or the Ranger is the better bakkie... 🙂

The goodwe is a good machine. The only thing I have against it is that we discovered recently that it does not bond neutral and earth on the backup side while islanded, and technically this means it is not SANS compliant.

While I personally like GoodWe hybrids, there's a couple of things that you have to double-check before each order:

• Some of the GoodWe hybrids have a very weak backup side. Inverter is rated for 5000VA for example, but the backup side is rated for 2300VA only and that really sucks. GW5048-EM is an example.
• GoodWe inverters can't be stacked (or paralleled) in order to build a system with a higher backup power. You can have 2 or more hybrids in a house and they will work together, but once the grid goes down, they will not cooperate and therefore you have to manually split your essential loads between the inverters. Not very convenient.
• While some models are still designed for a standard 48V battery, the new 3-phase hybrids require high-voltage battery (180-550V). Later you will find, that in order to build such a HV battery bank, you have to buy at least 10kWh of lithium which is not cheap.

But there's also a lot of good things about the above GW machines. For example, most of them don't have fans, so they are silent and just humming. Everything is easy to set-up and the installation itself is a quick process even if you're rookie.

 

There's a tons of info on Victron stuff on the forum, so I'd like to mention just the biggest differences in design philosophy:

• The main portfolio of Victron gear standardizes around 48V battery bank, which is cheap to star with and cheap to upgrade over the time.
• Also, Victron gear can be stacked/paralleled, so if you need to have massive backup power, you can.
• Victron is like a Lego, so you can combine a separate MPPTs, inverters, monitoring devices and control panels in order to build a tailored PV system.
• There's plethora of settings that you can tune and play with. And there's a nice community where you can get help and advice when you're lost.

 

Both vendors earned their place on the solar market, but each of them is targeting a slightly different customer segment.

I have a Goodwe 4.6kW ES inverter. As a result of the SSEG registration problems I experienced (inverter > 3.5kWA on a single 60A supply) I almost considered changing to Victron because you can software limit the maximum output. This is not possible with the ES Goodwe inverters at the moment. So this is another issue potential buyers must take into consideration.

Another difference is the higher maximum DC voltage input the Goodwe has compared to the Victron MPPT's. The longer panel strings possible with the Goodwe simplifies the installation and reduces cost.

 

12 hours ago, Pietpower said:

SMA sunny boy - Is this an off grid? Very cheap for a hybrid?

The SunnyBoy is a PV-inverter. The SunnyIsland is a battery inverter. You combine the two to make a hybrid setup. In other words, it's a very similar topology as when you combine a Victron Multiplus/Quattro with a Fronius PV-inverter. A combo like this will cost more than the equivalent Victron setup.

From what I can tell - you would need a SMA Sunnyboy grid-tie PV inverter, PLUS a Sunnyboy Storage Battery inverter...

Check this pic

Amazes me - SMA is an awesome product (from what I've been told) but they don't exactly make it easy to understand their system and options. I find the same with Victron - as an end user I want an easy to understand schematic of what my options are and what "modules" I would need for the setup, but such info one has to dig up from various sources...

 

 

27 minutes ago, Pietpower said:

So the sunnyboy is a grid tie inverter which switch off when the grid goes down and you cant connect batteries to it? Is this correct?

I presume the sunnisland then can't take pv panels and is basically a ups?

Yes and yes... BUT... you can tie the Sunnyboy to the SunnyIsland, and then it can operate off-grid. As I said, very similar to what we do with a Victron inverter and a Fronius PV-inverter (which can also be placed on the output)... but it costs more.

12 minutes ago, markus_m2 said:

I find the same with Victron - as an end user I want an easy to understand schematic of what my options are and what "modules" I would need for the setup

Have you watched the ESS webinar? Look for it on youtube, it explains all the options.

20 minutes ago, Pietpower said:

Like so?

Yes. Except I am not sure if the Sunny-Island has a input/output/transfer switch similar to the Multi or if that is separate. That's the bit I don't know. But I do know the -Boy ties with the -Island and works off-grid just fine.

SMA is a very reputable German brand, Tier-1 manufacturer in the solar inverters world, I would say.

But the SMA's ecosystem is built on a very different philosophy then everything else on the market: they extensively rely on AC coupling. They use AC coupling even for charging/discharging batteries, for combining wind+solar, etc. This philosophy works great for large-scale installations, peak shaving, for combining Flow and Vanadium Redox Batteries together with the conventional FLA and Lithium battery banks.

Based on the above, SMA is a very popular brand for the commercial installations and large solar parks here in Europe. Also, a very good use-case for SMA is micro-grids. For example a distributed solar+wind+redox micro-grid for a whole village, remote island in the middle of nowhere, or mining operations.

Some of the installers, who gained their experience during building abovementioned solar parks, are using SMA inverters for the residential installations too. But in most of the cases, all of these residential SMA installation are pure on-grids, single-phase, with no batteries. And the reason is simple:  in order to build a residential PV system with SMA components, you have to combine a number of large boxes, where one set of boxes is working during the day, while the other set works during the night. And the energy flow between the boxes is via AC coupling, which means that you have to maintain sinewave generation even if there are no loads and you just want to charge the batteries from the solar. So, when looking at a small, residential hybrid installation, a SMA solution will be less energy-efficient and will cost much more than GoodWe, SolaX, Victron, InfiniSolar, etc. Yes, you can scale SMA to 1MW using the same components, but do you really need 1MW of power at home?

Personally, I would never buy a whole train to serve me as a family car. And for the same reason, I would never choose a SMA system for the family PV as there are much better solutions available.

 

9 hours ago, Youda said:

SMA is a very reputable German brand, Tier-1 manufacturer in the solar inverters world, I would say.

Correct. There are some parts in the world where they walk right past the blue and buy only the red... cause blue is considered tier-2. Meanwhile in South Africa.... "OMG I can't afford the Rolls Royce I'ma buy a Tata instead..." 🙂

9 hours ago, Youda said:

you have to combine a number of large boxes

As I understand it, the way this system islands is not through an internal transfer switch (like in a Victron or a Goodwe), this is done externally. The diagram you posted also doesn't show the input/output one might be used to in these other systems. I've also wondered in the past if this wasn't part of the reason there was so much confusion in the local regulations which insisted on an external interlocking device that would ensure both are not connected at the same time... maybe the literature they used to develop it assumed that setup.

1 hour ago, plonkster said:

The diagram you posted also doesn't show the input/output one might be used to in these other systems.

Oh no! Trust me - you don't want to see fully-blown SMA PV system diagram! There are so many cables, relays, distribution boards.... It's an "electrician's dream"...

• For an off-grid setup Sunny Island has the capability to switch between solar and grid, or between solar and genset. It has an internal transfer switch.
• For a proper hybrid setup, you need to add an external ATS that will disconnect the system from the failed grid, while keeping Sunny Island AC coupled with Sunny Boy.

 

Wiring example of Grid-Tie solar, with increased self-consumption and a single-phase backup:

 

ATS for a single-phase backup:

 

The above solution is able to cooperate with the grid, there's increased self-consumption for the loads on L1 and once the grid is down, you will have PV+battery backup, but all the phases will be fed from L1. The failover is not instant and the backup is not suitable for running 3-phase motors. And now imagine a diagram of a grid-tie system with a backup suitable for powering 3-phase motors...

The SMA gear is great for microgrids, but I'm still waiting for a day when I will meet someone who has the above "nuclear powerplant" installed in his boat or caravan...

 

 

Edited February 19, 20205 yr by Youda

1 hour ago, Youda said:

The failover is not instant

That's what I heard too. When the grid fails, the effect is a bit like you get with backup generators at hospitals/hotels. A 20 second outage... then you hear the generator start, and then the power returns. Equipment that needs to survive the outage gets a battery/UPS that is capable of bridging those seconds/minutes.

 

Hi,
I just had a system installed and we started with a Growatt 5KVa inverter. It was nice, the portal was nice,  however the switch-over time from power failure to backup is 0.5 sec and that completely negates having a computer or a printer on as everything switches off momentarily.
We just (yesterday) switched to a Goodwee ES 4.5, however this is riddled with issues from:
Wifi dongle not working (at all)
Intermittently switching itself off and rebooting.
Lights flickering at random
Appliances switching off momentarily.
At this point in time, considering the 4 week installation process currently and the money spent, I am quite disillusioned with the cost vs results. 
 

1 hour ago, tumad said:

We just (yesterday) switched to a Goodwee ES 4.5, however this is riddled with issues from:
Wifi dongle not working (at all)
Intermittently switching itself off and rebooting.
Lights flickering at random
Appliances switching off momentarily.
At this point in time, considering the 4 week installation process currently and the money spent, I am quite disillusioned with the cost vs results. 
 

That sounds like a lot of bad luck. What does the installer say?

10 hours ago, tumad said:

Hi,
I just had a system installed and we started with a Growatt 5KVa inverter. It was nice, the portal was nice,  however the switch-over time from power failure to backup is 0.5 sec and that completely negates having a computer or a printer on as everything switches off momentarily.
We just (yesterday) switched to a Goodwee ES 4.5, however this is riddled with issues from:
Wifi dongle not working (at all)
Intermittently switching itself off and rebooting.
Lights flickering at random
Appliances switching off momentarily.
At this point in time, considering the 4 week installation process currently and the money spent, I am quite disillusioned with the cost vs results. 
 

Hi Tumad,

also have a Goodwe48ES. 
had some teething pains, but 95% happy with it at the moment. 
check the firmware, think the latest is 171710. 
then there is firmware for the wifi as well. 
im still stuck on 121206 due to an issue with the newer firmware stuffing up the soc calcs on lead acids. 
 

17 hours ago, tumad said:

Hi,
I just had a system installed and we started with a Growatt 5KVa inverter. It was nice, the portal was nice,  however the switch-over time from power failure to backup is 0.5 sec and that completely negates having a computer or a printer on as everything switches off momentarily.
We just (yesterday) switched to a Goodwee ES 4.5, however this is riddled with issues from:
Wifi dongle not working (at all)
Intermittently switching itself off and rebooting.
Lights flickering at random
Appliances switching off momentarily.
At this point in time, considering the 4 week installation process currently and the money spent, I am quite disillusioned with the cost vs results. 
 

GoodWe will replace your inverter, 2-3 weeks is the waiting time unfortunately. Once it's up and running its all good. With My first inverter the dongle failed and was replaced in 2 days. Then the inverter failed, dead, dead, dead... This was over Christmas, so there was a backlog of repairs in January. It took 3 weeks to sort out. Who supplied the unit? 

Hi,

If you can afford a rugged Toyota Land Cruiser, buy Victron. If you can only afford a Corolla, nothing wrong with a Voltronic solution. Just ensure it's installed properly and with quality search protection on both AC input and AC output. Axpert MKS, King and InfiniSolar series can parallel to expand or create three phase systems. The Segen Kodak branded King is available with comms to the Pylontech BMS.

Rentech will also have their Oryx 5kW/5kVA with similar features and a direct comms interface to their Rentech LFP batteries available mid April.

2 hours ago, HannesE said:

If you can only afford a Corolla

Hah! I'm a long time Toyota fan and I've had two Corollas in the last 20 years. I think it is unfair to compare a Corolla to any Voltronic... 😛

 

On 2020/03/10 at 2:33 PM, Pietpower said:

That sounds like a lot of bad luck. What does the installer say?

HI its working now except random shutoff and reboots which is not very handy

The goodwe es is a brilliant machine. They fall a little short on software and they have had a fair share of firmware bugs. Build quality and component selection im sorry to say surpasses victron by quite a bit. Before im shot at dawn im a massive victron fanboy and to someone like me blue offers the best all round. But credit where its due. The hardware issues guys have with them are almost assuredly because of improper installation, Oversizing backup or high inductive loads. Bonding does happen, guys just dont wire them right. The pe earth is connected to the chassis while the unlabeled earth connection is bonded see pics.

In short its the perfect inverter for a certain type of use case.

Cons

No generator

Off grid not recomended

No high inductive loads.

No parallel 

Not for the tinkerer

Long panel strings not ideal in partially shaded cases 

Annoying connectivity and firmware issues and propriety software nonsense.

Pros

Exceptional quality, nippon panasonic omron etc 

Lower noise and fanless

Ip65 if i recall

All in one solution with 100A dual tracking mppt 

Simple to install and setup so less install fees

Long strings higher voltage pv so less cabling and again less install fees. 

Upgrade paths starting with no battery grid tie, or no panel ups. 

Higher eficiency on grid hybrid because its transformerless vs say victron. 

Goodwe support isnt bad. Not great but not bad.

Hi, can you please explain this in more detail. Are you talking about bonding when in island mode? 

"Bonding does happen, guys just dont wire them right. The pe earth is connected to the chassis while the unlabeled earth connection is bonded see pics."

58 minutes ago, FixAMess said:

Hi, can you please explain this in more detail. Are you talking about bonding when in island mode? 

"Bonding does happen, guys just dont wire them right. The pe earth is connected to the chassis while the unlabeled earth connection is bonded see pics."

Yes. My thumb is on the neutral and the circuit path is through a relay to earth thats is only connected to the unlabeled earth.

31 minutes ago, Weasel said:

unlabeled earth

What would be really useful is if you could show what unlabelled thing this is and how to wire it, so the guys with the floating supply can rectify their setup.

If I read this correctly, you're telling me this terminal:

... actually has a bonding relay attached to it, so you just need to connect an earth to that and it will bond correctly?

That's like... seriously.... should be in the manual or something 🙂

Would also be interesting to see if all of them has that.

Edit: Finally, someone who knows what they are talking about who can put the matter to bed!

Edited July 23, 20204 yr by plonkster

13 minutes ago, plonkster said:

What would be really useful is if you could show what unlabelled thing this is and how to wire it, so the guys with the floating supply can rectify their setup.

If I read this correctly, you're telling me this terminal:

... actually has a bonding relay attached to it, so you just need to connect an earth to that and it will bond correctly?

That's like... seriously.... should be in the manual or something 🙂

Would also be interesting to see if all of them has that.

Edit: Finally, someone who knows what they are talking about who can put the matter to bed!

@plonkster, thank you...