In Blog, Inverters, Micro Inverters & Optimisers, Uncategorized

Tigo Optimiser Recall?

At the time, Tigo optimisers seemed like a good idea. I’ve even spruiked Tigo as an affordable shade solution in a past review. But my recent Tigo testing has uncovered two major issues that render Tigo optimisers worse than an empty black box. In this Tigo optimiser review, I’ll explain why many, if not most Tigo optimisers may need to be recalled in order to update the firmware.


But, before I explain to you why I think Tigo should recall and upgrade many of the optimisers sold over the last few years, I’m going to explain three different situations where Tigos are commonly used. Not all of them are clever.

  • The first shade scenario where Tigo’s make the system work worse. That’s right, even if they are operating correctly, Tigo optimisers can drag down the performance of a solar system. 
  • The second shade scenario, just to soften the blow, I’ll show you a shade situation where Tigo optimisers make a solar system work a bit better. 
  • The third example I’ll give is where functioning Optimisers (or microinverters) are absolutely essential.  

However, that will lead me to the huge problem I’ve found with Tigo optimisers. And you’ll see why in this review I insist Tigo should recall and upgrade the firmware of many of their optimisers sold over the last few years. If you want to cut to the chase and read about the issue that floored me, click here. (if you’re reading this on a phone, you’ll need to scroll down a little further after clicking)

Tigo Drags down the performance of a solar panel 

First, let’s look at the example where a correctly functioning Tigo can drag down the performance of a solar system. Have a look at these two examples. One has Tigo optimisers installed, the other doesn’t. Let’s say each panel is operating at 300w and at that time of day there is going to be shade on part of the solar panel.  

A Standard String System

Looking at the system without optimisers first. Will the string be dragged down because of shade? No. Despite what you have been told, quality modern string inverters are much smarter than that. Instead, the bypass diode will engage on that cell string and the panel will run at 200W. It blows my mind that people in the solar industry still don’t seem to understand the simple function of a bypass diode and quality string inverter. 

No Tigo Optimiser




A Tigo String System

Now let’s put on Tigo optimisers and see what happens. The good thing about Tigo, is that it treats the panel gently. Each panel only has to handle the power and voltage of just that one panel. Which means that when there is shade, the panel isn’t in danger of being damaged by the hot spots that are normally created when a panel is shaded. Because the panel is not in danger; the bypass diode does not engage. But because the bypass diode doesn’t engage, in this specific type of shade, the whole panel will be dragged down, and it will work at around 20 or 30 watts.  



Fronius vs Enphase Shade Solution

If you want a deeper dive into why this happens, check out this Enphase video. Tigo works pretty much the same as Enphase. My point is that the addition of Tigo to a string system can sometimes make that system perform worse. 

Tigo’s advantage with split cell panels 

But Tigo doesn’t always drag down a panel’s performance. Let’s turn things positive for a bit and show off Tigo in its element: Tigo optimisers on a split cell panel with top or bottom shade. Check out this example. 

We’ll start with the unoptimised system. Again, let’s say each panel is running at 300 W. If you shade 4 panels on the unoptimised system, the 4 panels will be bypassed. The system will then run at 5x 300 watts, or 1.5kW. 


Now we’ll look at the same shade situation, except with Tigo optimisers attached to each panel. Because each optimiser can operate at its own current value, then it can choose the 4 half panels, running at 150watts, and the 5 unshaded panels. Tigo outperforms the unoptimised system by 600 watts. 


Optimisers and micro-inverters work really well on split cell panels when the entire width has partial shade. 

Fronius or Enphase in the shade

If you want to understand why optimisers allow the top half of the split cell panel to keep running, watch my video on Enphase with split cell panels. Again, Tigo responds the same way as Enphase on split cell panels. 


Tigo in Complex shade 

Now let’s mix it up. Let’s say the shade falls on three panels, but two of the panels are only shaded across one cell string.  


First on a Tigo system the middle panel will operate at 150 watts. That’s the benefit of a split cell panel and an optimiser. 

Next, look at the left-hand panel. Because an optimiser is installed, the bypass diode often doesn’t engage. So the entire panel may be dragged down to about 30 watts. This doesn’t always happen – but happened multiple times when I was testing it using different string lengths and different inverters.

And the right panel may work at around the same as the left one, or a bit less. Lets say 20 watts. So the three panels give us a total of 200 watts. 



The unoptimised system with complex shade 

Now let’s look at the same system without the Tigo optimisers. 


The middle panel will be bypassed which means it will run at 0 watts. Bugger. 

But because we don’t have an optimizer installed, the left panel will bypass the right side cell string in order to protect the cells from hot spot damage.  A happy result of that string being bypassed is that it won’t drag the rest of the panel down, so it will run at about 200 watts. 

The right panel will bypass 2 cell strings which results in that panel operating at about 100 watts. 

So, in this case, at this particular time of day, with this amount of shade on a split cell panel, you’d often produce more without Tigo optimisers. 

It’s pretty complicated, isn’t it! Not just as simple as whack a Tigo on and all your shade problems will be solved. 

Tigo on split orientations 

Let’s move on and look at a situation where Tigo optimisers (or microinverters) are essential. When you have a single string of panels split across multiple orientations, you must install optimisers. This is not only required by Australian standards, but if you don’t do this, your solar will perform miserably. 

I’m going to start off with the basics, and I’ll explain why this layout absolutely needs optimisers or microinverters. If you already know why, skip ahead to the next heading. 

Let’s install 12 panels without optimisers (see image below). At 9 am in the morning, let’s say the northern panels see fairly decent sunlight so they want to run at 180 watts each. 180 watts would be made up of 30 volts and 6 amps of current. 30 volts times 6 amps equals 180watts. 

But the panels on the west are facing away from the sun, so they only want to run at 90 watts. That would still be about 30 volts, but only 3 amps of current.  

Note, solar panels typically run at approximately the same voltage all day, usually about 30 volts. The current is the figure that changes throughout the day. 

As mentioned earlier, these panels are connected in series, so if you understand current (as in amps), then you would have already seen the problem. 

A Kink in the garden hose 

Think of a series string as all the power from the 12 panels running through the same garden hose. The “kink in the garden hose” theory doesn’t always apply to solar panels, but in split orientations, it does. 

kink-in-hose-no-tigo-split orientation

Think of the current (or, the 6 amps and 3 amps) as the amount of water running through that hose. How much water is coming out the end of the hose at 9 o’clock in the morning? 6 amps or 3 amps? 

The problem is, it can’t be both. 

The panels on the west, running at 3 amps, acts as a kink in the hose, so only 3 amps can run through the whole string. This means every panel will only work at 3 amps and 30 volts, or 90 watts. We’ve just lost a heap of energy from the northern panels. 

Solving the kink with Tigo optimisers 

Fixing this problem is the job of any optimiser or microinverter. So let’s install Tigo optimisers on every panel and see how it works. 


The panels on the west will still only work at 90 watts. Optimisers don’t magically create energy. The Tigo receives that 90 watts as 30 volts and 3 amps. Power equals voltage times current. 

The optimisers job is to increase that current to 6 amps, so the other panels are not restricted. Again the Tigo optimiser doesn’t magically create current.  Instead, it increases the current by reducing the voltage. 

It reduces the voltage (or bucks the voltage) to 15 volts. To balance the equation, it uses grade 5 maths. It increases the current to a value of …. have you worked it out?  …  6 amps.  


15 volts x 6 amps is still just 90 watts. So we haven’t magically increased the power production of that panel. We’ve just made it work at the same 6 amps of current as the rest of the panels in the string. Now the northern panels can run at 6 amps and, 30 volts, which equals 180 watts. 

Now that you know how it’s supposed to work, let’s see how it worked in realityLet’s see what went wrong and why I am pushing for a massive Tigo product recall, or product upgrade. 

Here’s my test. 

Why Tigo optimisers should be recalled

So the curveball in this blog is thanks to my good mate and solar industry legend, Jack Longy Long. Jack called me earlier this year to talk about a Tigo installation installed by a fellow Solar Cutter. The Tigo optimisers were installed on a single string of panels, across different orientations. The Tigos were clearly not doing their job. He knew I was in the middle of Tigo tests, so he asked me to simulate his problem to help a fellow cutter. He was definitely on to something, but it took me another 6 weeks to work out exactly what that was. 

Jack Longy Long Tigo
System 1

I set up two systems of 19 panels each on 2 Fronius inverters. 5 panels north and 12 panels west. On one of the systems, I put optimisers on seven panels. 5 northern panels and 2 Western panels. I connected these panels in series, on one input of the inverter. Dealing with this split orientation should be a piece of cake for Tigo.  

The other 10 panels went on the other input of the Fronius inverter.  

System 2

On the second system, we just wired it the way it has to be. 5 panels on one string and 12 on the other. I monitored both inverters with solar analytics. 

It turns out that my mate Jack was right. The Tigo system worked pathetically – as if no optimisers were installed at all. In the morning, the panels that were facing west dragged down the northern panels. In the late afternoon, the western panels were dragged down by the northern panels “It was as if there were no Tigo optimisers installed at all.” 

To find out what was going on, I connected the Tigo optimisers to the Tigo monitoring platform. We had a few rainy days between testing but when the sun came back out, suddenly the system was working correctly. It didn’t make sense. Not knowing how to simulate the problem again, I switched out the optimisers for new ones.  This time it worked even worse than the first test. 


Tigo optimisers need initiating 

After a lot of head-scratching, and with Tigo’s help, we worked the problem. The optimiser firmware needed upgrading. Tigo claimed they had a problem with a particular batch of optimisers with a specific hardware version coming out of the Philippines. The optimisers were programmed wrong. They would only start working as optimisers after they were connected to the internet. 

Did you get that? The $75 selectively deployed Tigo optimiser won’t work unless you connect it to their $800 monitoring hardware. That’s a problem. But how big is this problem? Is it limited to just one hardware version that came out of one factory as Tigo suggested, or should there be a Tigo optimiser recall issued? 

How widespread is Tigo’s issue? 

I tried the same test with another hardware version – but still from the same factory. No luck. Far out. I had the same problem. The optimiser didn’t work until I connected it to Tigo’s monitoring hardware. So I called around and found a supplier with a third hardware version. Again, the same problem. At this stage, all of my optimisers had been manufactured in the Philipines, albeit purchased 18 months apart. Tigo suggested I try an optimiser from their Chinese factory

Tigo Optimiser Recall Tested Production Lines

I called around distributers and found an optimiser that came from Tigo’s Chinese factory. Our supplier delivered two in an uber. I installed them straight on the roof and waited for the results. Bugger. Tigo’s theory was wrong. It’s much worse than they thought. I’ve now tested Tigo optimisers from the factory in the Philippines and the factory in China, including 4 different hardware versions. None of them work, unless you connect them to Tigo’s online monitoring. 

How Far Back Does the Tigo Issue Go?

I then started looking at Fronius monitoring from systems we had installed with Tigos back in 2019. We found multiple sites where the Tigo optimisers were not working, and we found remarkable improvements when we updated the firmware.

What is the extent of this problem? I think it’s highly likely that every Tigo optimiser that has been installed in the last few years, without the expensive Tigo monitoring hardware, have serious firmware issues. Unfortunately, it’s not as simple as calling the Tigo an empty black box that does nothing. Our testing has shown occasionally the Tigo works and improves performance, sometimes it does nothing, and sometimes it severely drags down performance. The problem is intermittent and it’s difficult to identify. The Tigo optimisers with the faulty firmware will keep playing up until someone temporarily installs the Tigo gateway hardware, and connects the optimisers to the internet to update the firmware.

Tigo Issue Diagnosis

How do you find out if the optimisers you installed are the faulty ones? If you’re clever, you can look deeply into the inverter monitoring platform, and make an educated guess if the current should be higher or lower than it shows. A telltale sign is the voltage and current graphs saw toothing, showing the intermittent nature of the issue. If you identify an issue, drive to site, connect the optimisers to Tigo cloud connect, and see if the current value in the inverter monitoring platform increases on an average day. We’re working on a way to identify the issue while on-site before we upgrade it. But the intermittent nature of the Tigo fault mixed with the dynamic nature of string inverter solar systems is making that difficult.

Tigo’s response

I’ve spent more time on these Tigo tests than any solar product test I have done before. I’ve given Tigo ample evidence and had almost got to the point where they sent out multiple Tigo “Cloud Connect” devices to fix this issue. But then Tigo changed their mind. They are now saying they don’t believe it is a widespread problem because they haven’t seen the issue anywhere else.

Seriously, Tigo. If you don’t have eyes, how do you expect to see? Without Tigo’s monitoring in place, there is no clear visibility to see the issue. If Tigo receives a complaint where an installer recognises an issue, then Tigo will request the system is temporarily connected to “Tigo Cloud Connect” to see what the issue is. On connection to “Tigo Cloud Connect”, the Tigo firmware is updated. Tigo can then “prove” that there is no issue with their monitoring. The installer is left confused and moves on to the next stitch-up. Tigo comes off looking like the good guy.


Fully functioning Tigo optimisers are not necessarily beneficial in shade situations. A little bit of shade on one panel can drag the whole panel down. If you didn’t have Tigo installed, that panel would have used the bypass diode to bypass the shaded portion of the panel, resulting in higher production. 

Tigo optimisers can work well with a particular type of shade on split cells panels, and they are also necessary if you have panels on the same string in multiple orientations. 

However, my tests in the office, and in the field have shown that multiple batches of Tigo optimisers are not working. I’ve identified faulty Tigo optimisers from 4 different hardware versions that we purchased between January 2020  and July 2021. We’ve also tediously analyzed and rectified faulty optimisers from several installs that we did back in 2019. The solution is the optimisers need to be connected to the internet in order for them to start working.  This involves about $800 worth of hardware being installed and left on the premises overnight. Tigo so far have been extremely difficult to deal with, leaving the burden of proof for each installation in our court.

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54 Comments on Tigo Optimiser Recall?

BM118 said :Guest Report 4 weeks ago

Is this issue still ongoing with hardware purchased in 2024? Surely they have started shipping hardware with a fixed firmware by now?

  • 2261
Gergely Pongrácz said :Guest Report 6 months ago

Without this guy this never would turn out. I don't know if it's sad or a happy thing that there is Mark in full interest of the topic, chasing empirical evidences. Thank you for this detailed post.

    mika aarnio said :Guest Report 7 months ago

    Now Tigos hardware costs only 220 euros in europe. Even Tigo says now: Required CCA + TAP I just installed 10 tigos to cheap 410 w astronergy chinese panels , only 99 euros / each now, cheap stuff. Greetings from Finland.

      Peter Strous said :Guest Report 10 months ago

      How to determine if your Tigos are working? Tigos are impedance matchers, and in case of shading they should exchange potential energy (Volts) for current so the current from the shaded panel matches the maximum current that the sunny panels of the remainder of the string can supply. After all, the whole idea is that the other panels can still produce maximum energy and are not impeded by the one (or few) panels in the shade. In other words, if your Tigos operate as they should, when shade sets in, provided solar radiation remains the same, your inverter monitoring system should report a fairly consistent current while the voltage drops. If your Tigos do not operate as they should, when shade sets in, the current of the string will collapse and the voltage will remain similar. E.g., if your string V is 400V and your current changes from 5.0A to 0.5A when shade encroaches on your string, you lose 4.5A (5.0-0.5) x 400V = 2.25kW

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      Marco Maljaars said :Guest Report 11 months ago

      Hello Mark, Fantastic article and analysis. So from what I understand is that shade from bottom to top Tigo is working. But left to right Tigo overules the diodes of the panel. I can see such behavior on my system. All Tigo and CCA and with Jinko Tiger 370 N type: JKM370N-6TL3-B. One panel B3 is not performing at all, even with only 10% of shade. It seems the Tigo is dragging the panel down. See my video: I am doubting to remove the Tigo from this B3 panel as it does not handling the shade and overrules the panel diodes. Cheers, Marco

        Greg Smith said :Guest Report 12 months ago

        Why would anyone think installing a string of modules (not panels) across different orientations is a good idea, even when using MLPE? That goes against common sense, and the manufacturer's design criteria,

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        Mark Cavanagh said :administrator Report 12 months ago

        It’s difficult. I really need to do a video showing how you can tell if works or not. Basiy you need to get on the roof with 2 clamp meters, measure the incoming and outgoing current, and shade the panel. If it works, you should see consistent differences between the input and output.

          Petr said :Guest Report one year ago

          Hello, I have similar experience with Tigo, even I didnt read this text before. I just wonder how to recognize chinese and phillipines products based on serial number. I requested Tigo about all firmware versions loded into my optimizers. But their technical support is even very poor or very clever ;). I live in Europe and other experts around facing similar experience and some of them dont have no information. I think that findings listed need to widespread over EU customers as well. Thank you Regards Petr

          • 25216
          Thomas said :Guest Report one year ago

          Hi Mark, your great article made me think about what I am currently planning: I'm also in the northern hemisphere and currently thinking about an installation with a Fronius GEN24 8.0 Plus inverter, BYD battery, and a total of 32 Jinko Tiger Neo modules (420 Wp) positioned on three sides of the roof: two strings with seven modules each on the southeast and northwest connected in parallel to MPPT1 plus one string with 18 modules on the southwest connected to MPPT2. A chimney on the southeast string will lead to shading that will affect some modules (hopefully only max. two at a time). The big question is whether this requires optimisers (Tigo or alternative) or whether the Fronius inverter will do a good or even better job without optimisers also in this case (two strings connected in parallel). As the two strings face opposite directions (southeast vs. northwest), I planned to connect them in parallel. Not sure whether the shading should lead to a different design. Reading your article, the option to avoid any optimisers would definitely be great. I would also love to be able to use the Fronius GEN24 inverter for various reasons, some of which are informed by your great videos.

            Frank M said :Guest Report one year ago

            Interesting article, thanks for your work. On the other side of the globe (the Netherlands) I have a small single string system with a TAJ optimizer, 4 panels west equipped with Tigo’s and 6 panels east without Tigo’s. The performance is absolutely lousy. In the morning 6 panels east often produce zero on a cloudless day, but on other (sunny) days provide a good performance. Performance is often intermittent. Afternoon performance is bad always, but could be related to the four panels not meeting the minimum startup voltage of the optimizer. Only around noon when the sun is on both east/west panels performance is ok. Does this sound like a related issue?

              Darren said :Guest Report 2 years ago

              Hi Mark, I extended my system back in 2020 with an array which gets quite a bit of shade during mornings and evenings, so added the Tigo TS4-A-O's when I installed. They appeared to do very little to me, but was assured they worked out of the box. 2 years on, and after reading your article, I decided to invest in the CCA. Once installed and the Tigo's linked up, the power curve the next day was very different, producing noticeably more power in the mornings and evenings. So thank you for taking the time to write this article, it certainly helped me out.

                Diego said :Guest Report 2 years ago

                Hi Mark, I'm a big fan of yours from Spain. I'm recently having a funny behaviour with my Fronius Primo and Tigos. I had only one string of 5 350W panels each one with a Tigo attached and the system worked very well, Tigos engaging as they should. I had to config MPPT to 80V as the string voltage was under 200V. Now I installed a second string of 9 panels, all of them with Tigos, they engage as they should (looks like). MPPTs 1 and 2 are now activated, 80V minimum threshold but only string 2 seems to be working (9 panels) and string one seems to be adding just the power of one or two panels. I have a spare panel and optimiser waiting to be installed adding to string one to make 6 panels and rising the voltage to 180V ish, hoping to get better results but I'm not really sure that would sort out the issue. Wondering if you've seen something similar due to your vast Fronius experience.

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                Håkan Olofsson said :Guest Report 2 years ago

                Thank you for a very interesting and useful article! I think I have this problem on my recently installed system in Sweden, but my installer believes it is all good. In brief: I have 12 panels in a string, mounted in 3 columbs of 4 panels. They have gradually decreasing shade up till around 2pm when they all have full sun, therefore the 8 most shaded have Tigos installed. This string gives almost no power until the sun has reached about 50% of the last column, i.e. 8 of 12 panels in full sun and 4 partly shaded. With 8 panels in sun and 4 entirely in shade I get almost no power (0,1kW). BUT, if I cover these 4 panels with blankets instead, then I get full power from the 8 in the sun (about 2kW when tested). I don’t see any saw tooth pattern in the current graph though. Do you think this can be due to faulty Tigos? I have photos, power/current graphs etc documented if it would be of interest for you. Best regards, Håkan Olofsson

                • Sweden
                Craig said :Guest Report 2 years ago

                Wow - i thought i was going mental - i have 10 tigo spread around my panels - and one string just does not perform correctly when shaded (13 panels) - of which 6 had the tigos - these panels are in landscape orientation and i can see the whole string being dragged down rather than optimized as the sun shades the optimized panels. I too have tried to get onto Tigo thinking it was a problem with the optimizers but they have been very slow to return any calls (i.e. none returned) What do you think we should do about escalating this ? Craig

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                Peter Strous said :Guest Report 2 years ago

                Thanks for your great research and sharing Mark. I have Tigo issues myself currently. Re: "Tigo’s theory was wrong. It’s much worse than they thought" or perhaps it's much worse than that they admit to........... Commercial interests might be in the way of the truth....

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                Peter Strous said :Guest Report 2 years ago

                And Mark, you are unique! Your dedication to fully understand and share what is happening and backup claims or uncover BS, has no equal. Thanking you so much!

                • 5062
                Peter Strous said :Guest Report 2 years ago

                Just put 6 Tigos on a string of 6 in a Solax system with another string of 12 without Tigos. That allows some comparison between the two strings. This time of the year the shade of 1 tree moves concurrently over both strings. The 6 Tigos do not appear to make any difference to the output when partially shaded. MPPT range 125-530V. Panel open circuit V = 38.3V. Hence when 2 panels are shaded, the 4 panels should still provided full power. Currently they do not. I will test each individual panel when the ordered panel tester arrives, and provided they are OK, Tigo will be contacted.

                • 5062
                Peter Strous said :Guest Report 2 years ago

                Hi Mark, just appeared to have picked up an error in your article. It states: "System 1 - I set up two systems of 19 panels each on 2 Fronius inverters. 5 panels north and 12 panels west. " Here in SA 5+12=17, not 19 only minor for such great work!

                • 5062
                Peter Strous said :Guest Report 2 years ago

                Mark, that is absolutely gold! This is the kind of investigation that needs to be taught to any installer! Thanks for your perseverance and attention to detaill to get to a full understanding of operation. cheers, Peter.

                • 5062
                Harry said :Guest Report 2 years ago

                Hi Mark I've really appreciated your posts and they have helped me narrow our choices down for a new system we're looking to have installed. We have a NNE facing roof and plan to install 6.6 or 7.8KW system. The issue is winter. There's a large tree out the back that does provide a fair bit of shade up until around midday. I had been leaning towards DC optimisers but on reading this post and others, I'm wondering whether it will be a worthwhile add? Mostly now questioning it after reading this article... Any thoughts here would be greatly appreciated.

                  Charlie said :Guest Report 2 years ago

                  Hi Mark, An excellent article. I an a designer of solar powered electrically propelled canal Narrowboats. The cabin roofs of our boats are covered with marine quality PV panels bonded to the deck. Recently we decided to try Tigo’s optimisers together with the CCA system. All was well until we cut shore power and went over to the boats batteries. The CCA lost power temporarily so the whole system went into Rapid Shutdown R/S). It was impossible to recover from this situation by following the advice from the Tigo web site. It was only after we requested that this feature be removed via the software and the CCA put on permanent battery power that the system was restored. However since then various TS4-A-O units are intermittently shutting down. One unit has shut down completely now. Tigo support engineers have said it’s a connection problem between the PV panels and the Tigo units. and will not cover this under warranty. How ridiculous this statement is. The system was working perfectly before the R/S event. Then it was impossible to recover from this situation via the method they suggested. When they carried out a diagnostic investigation they said that the units had either been connected wrongly or that the connections were bad. Shame on Tigo, I’m sure that they are aware of this problem and they are doing everything they can to put the blame on the installation.

                  • BA3 5EX
                  Peter Olsen said :Guest Report 2 years ago

                  Are you able to put up a copy of correspondence from Tigo on the firmware problem please? I am considering installing them to assist with a shade issue but don't like the implications of the above. I wrote to Tigo but in their reply they refused to acknowledge that there is or ever was a problem with the firmware. They just said quote: "We have shipped over 4 million units and if there was an endemic issue we would be aware from multiple sources. To date this is not the case."

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                  Mark C said :administrator Report 2 years ago

                  Hi Rob, Yes, this is an ok application of Tigos- presuming they are actually working. In the afternoon, the eastern 2 panels will reduce the voltage in order to increase the current to the same value of the northern panels. All this will do is not "drag down" the northern panels. On the downside, at 8 am in the morning, your 2 panels will only work as well as the northern panels. But that's not losing too much.

                    Rob said :Guest Report 2 years ago

                    I'm in Northern hemisphere and have 6 panels South and 2 panels East. The installer fitted TS4 -A-O to the East panels. As the sun goes to the West in the afternoon, the east panels produce less power until they go into shade. Will the TS4 will do anything unless the East go into shade?

                    • BN12 4XQ
                    Jo said :Guest Report 2 years ago

                    Simply put. Tigo works best when the shade is "Row" wise rather than "Column" wise. That is, looking at a panel as depicted in your diagrams.

                    • 3095
                    Simon said :Guest Report 2 years ago

                    Hi Mark, Talked to Tigo support again to know what the optimiser rapid shutdown function should do when activated. As i understand now, it will isolate the solar panel from the string until the CCA gives the OK. This makes more sense as this way the rapid shutdown will make it safer to work. It also explains the designed dependency, because shutting down the AC power in case of a fire or other emergency will easily isolate the DC connected panels. This indeed makes rapid shutdown an unlikely cause. I do still have a suspicion a firmware bug may have been related to this new feature, but ther is no way to find out. I would understand if Tigo is reluctant to do a wordwide recall of these optimisers as there are so many of these out there, and sending engineers to every roof to check, replace or update these is a financial nightmare. Maybe they should offer a huge discount on the CCA package for affected customers instead if this is a bug. That would make more sense than endless tinkering on rooftops.

                      Mark C said :administrator Report 2 years ago

                      Hi Simon, yeh they do need to disable rapid shut down after it is connected to the CCA. SO like you say, not even a sparkie can fix it without the help of Tigo. I don't believe that is related to the fault. When the CCA loses power, the optimiser will shut down. So that's also what happens once you set up the CCA and remove it. The faulty Tigo isn't in rapid shutdown mode, it just appears to pass-through power, and does intermittently do something, but it does not optimise correctly.

                        Simon said :Guest Report 2 years ago

                        Hi Marc, I just had a long talk with Tigo Support. After some discussion about the issue i have a suspicion that the rapid shutdown feature is actually causing this problem. It may already be enabled, disabling the optimizer until it sees a CCA. This could be due to DOA testing somewhere in the supply chain or maybe they just left the factory that way. The easiest way to find out is just connecting the Tigo optimizers to a working CCA setup. The support engineer says only they can remove the rapid shutdown feature remotely for safety reasons, so it's not a diy job. The other way to check is to get up om the roof and measure, but i am not comfortable that high up, so i will leave it to the professionals.

                          Mark C said :administrator Report 2 years ago

                          Hi Simon, Tigo won't admit to the problem. Given you have a Growatt inverter, I'm almost certain that would not have a GMPPT (or shade fix). So Tigos may be helpful. Don't worry about a rapid shutdown. Tigo will have to send you a cloud connect, and then they will have to disable rapid shutdown before you take the cloud connect away. Let me know if you have success with this. I highly doubt Tigo will entertain the idea, but that is the solution and they know it.

                            Mark C said :administrator Report 2 years ago

                            Hi Tim, they work independently of each other. You'd want to check the voltage and current limitation of each panel and optimizer. Unfortunately, your Sungrow inverter won't deal that well with shade - because I don't think it has a GMPPT. But if you use the tigos, you'll want to check they are actually working by shading the panel and using a clamp meter on the input and output of the tigo. Do this over a 10 minute period because the issue can be intermittent.

                              Tim said :Guest Report 2 years ago

                              This is my system: Jinko Solar Tiger P-Type 390W Black Frame 132 Half-Cut Cells Mono Sungrow Residential G-RT 10 kW 3 Phase 2 MPPT Grid Connect. I do have some partial shading. My bro in law has given me a few tigo t4s-a-o (500w). I need a few more but can only find 700w. Will it work with a mix 500 and 700w? Or can I add ts4-r model (475w). Thanks

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                              Simon said :Guest Report 2 years ago

                              Thanks for the great article Mark. I have had the issue with the Tigo optimizers for well over a year now, but with no monitoring installed they are possibly bugged by the same firmware fault. I logged a call with Tigo because the affected string is producing next to nothing until the last bit of shade is gone. I do not intend to spend many hundreds extra for monitoring just two optimizers when my Growatt Inverter does that just fine. From what I understand the TS4-A-O optimizer will enable the rapid shutdown feature upon connecting to the Tigo CCA monitoring hardware and will be dependent on it's presence for eternity, because it does a rapid shutdown if the CCA goes down. This prevents me from just borrowing a CCA for checking and updating the firmware on the TS4-A-O optimizers. Another option I am considering is just tossing the Tigo optimizers and installing two Enphase Micro Inverters on those panels. But the inverter has two strings with 325W Panasonic Kuro panels. This runs up to 330V per string (mostly 300V), so with two panels less the remaining 3 panels might not be sufficient. To troubleshoot I have requested my solar panel specialist to bypass the last panel completely. It takes the whole string down way longer than the panel next to it, and will give insight if it is just one busted optimizer or the same firmware problem you described. At this point i am also considering expanding my system with panels on the side that gets the morning sun. There is a lot more shade there and the orientation is never optimal, so maybe Enphase would be better on that side anyway. I would love to hear your thoughts on the subject; Is the CCA indeed a single point of failure when connect TS4-A-O optimizers or can I just reset of decommision them from the CCA in some simple way so they will function as standalone devices? Tigo is looking into my problem, but reading your article my expectations on their ability to fix this are not great.

                                Oliver said :Guest Report 2 years ago

                                Hi, I have been chasing a different Tigo problem for the past month. It looks like a recent firmware upgrade on an internet-connected system is doing something nasty. Tigo Support has been really hard to work with, but I have more and more evidence of what is going on. This is an older installation with 3 SMA 10kW Sunnyboys with 1 MPPT tracker each. As such installations always required combiner boxes of multiple strings to a single inverter. In this case 3 inverters with 3 strings of 16 panels each - 48 panels per inverter - 144 panels and optimizers in total. Up until February, the system worked pretty well, with only a few error messages. Come March 2022 all 3 inverters would no longer boot up in the mornings - often 3-5h later while throwing disturbance error messages every few minutes. Looks like the parallel combined strings get into some sort of a race condition during startup. out of three combined strings, one will start showing very low production on the Tigo software, with the other 2 being at zero - with all three facing the same full sun exposure. Have been doing a ton of testing, swapping out SMA inverters (no change) as well as measuring and testing the entire system. Don't have the root cause just yet, but turning off the software optimization on the Tigos brought some improvement, and shutting off the emergency shutdown feature is allowing us to now do some more testing with the optimizers being offline. Happy to share more details and data directly.

                                • San DIego, CA
                                David said :Guest Report 2 years ago

                                "The solution is the optimisers need to be connected to the internet in order for them to start working." Yes, that is correct. How else would you get module level monitoring to the portal if you aren't using their communication equipment? I don't know of any company, microinverter, or optimiser, that doesn't require you to buy their fancy gateway/CCA/Ensemble/whatever. Other than the software upgrades, and a few bad batches from their Asian supplier, looks like they are doing what they are supposed to do. I have only used them on 20 or so installs, but they seem to work fine.

                                • VIC 3222
                                Elliot said :Guest Report 2 years ago

                                Hi Roob62. It's hard to say for sure without knowing all the details, but it sounds like the Tigo is not operating correctly. The point of the Tigo is to maintain the current when the panel it's attached to receives shade. However, if other panels without Tigo's also received some shade, then the amps of the whole string could be affected. The voltage changing with shade is normal though.

                                  Basile said :Guest Report 2 years ago

                                  Awesome blog Mark, many thanks for sharing your expert advice! Did you get any corporate update from Tigo since your article ? Greetings from Switzerland

                                    Roob62 said :Guest Report 2 years ago

                                    Hi! I have tigo installed on panel which gets occasional shade and when it happens the current of whole string drops by a lot while voltage rises but much less. In result one third of power is gone. By reading your article I understand the opposite should happen - the current should stay close but voltage should drop, right? Does it mean my tigo is faulty?

                                      Peter S said :Guest Report 2 years ago

                                      Thanks Graham! Had the very same issue in early 2021 on the other side of the globe, with 4 TS4-A-0 in a string of nine panels using Solis G4 inverter (no shadow management!) . Wasted weeks with Tigo support, ended up getting a CCU for testing that solved the issue. But after returning it some weeks later, system was behaving eratically again. Ended up purchasing a CCU (and adding some TS4). System working fine since then, only 500€ beyond planned budget. :/ Lessons learned: NEVER run a Tigo system w/o CCU permanently attached.

                                      • DE-4500
                                      Mark C said :administrator Report 2 years ago

                                      Thanks, Graham :). It's not easy doing backflips. But it's good to know that people are using the info!

                                        Chris said :Guest Report 2 years ago

                                        I have exactly the problem with Tigo which made the string worse. In fact, just paid to have them removed just recently. I have photos of the shading in the morning with matching detailed data downloaded from Solis to confidently say the Tigo units I have are problematic.

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                                        Grahame said :Guest Report 2 years ago

                                        Hi Mark, another excellent overview. I have 3 orientations, and seasonal shading, late last year my old 3kW system (half dead) needed replacing so after much research it came down to Tigo or Enphase, your glowing review of Tigo almost had me go down that route, I read and re-read your posts and eventually settled on Enphase, I'm a very happy camper with my 8.6kW system, electricity bill just received $270, same bill last year $1200. After spruiking Tigo it would have been very easy for you to keep silent about this issue, if only our politicians had as much integrity as you have shown. Thank you for all the genuine information available on your blog.

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                                        Mark C said :administrator Report 2 years ago

                                        Hi Mark, good question. Actually, most panels are not warranted in the shade even if you use an optimiser. But QCells and Sunpower have stood by their panel and given me the approval to install in shade - as long as it is not constant shade. I explain here:

                                          Mark said :Guest Report 2 years ago

                                          But if activated regularly, how long will a bypass diode last before failing? Then what happens...

                                            Mark C said :administrator Report 2 years ago

                                            Thanks Ben! Ha, that's interesting that Growatt is that stupid, I should have said "quality modern string inverters are not that stupid" I've tested sma, huawei, Fronius, Sungrow, Goodwe and SolPlanet. All of these seem to work pretty well with shade, but it seems the new Gen24 is the best. It's true that all maximum power point trackers are not created equal. I'll need to get a Goodwe to test. ---- Of course, a lot depends on string length and irritation and the panel bypass diode itself, so my blanket statements don't apply all the time. ---- Regarding your first comment about dragging down to 20 or 30 watts. Yes, Tigo does work in some shade situations, and i showed that working in a previous blog. I need to be more clear about the type of shade. I was talking about shade on 1 cell string. I've done that test multiple times. Jeff from Tigo didn't believe me, so I did it over the phone while he was looking at the monitoring. Thanks for the feedback! I'll reread the blog and clear up any poorly worded parts.

                                              Mark C said :administrator Report 2 years ago

                                              THanks TJ. The IQ8+ will be a gamechanger! Especially the version that can run permanently off-grid! We're installing a lot of Fronius Gen24 inverters that have the same feature (3kW of solar in a blackout, without a battery). Have you seen my YouTube review about Enphase in the shade?

                                                Ben said :Guest Report 2 years ago

                                                Hi, I don't agree with the statements you've made that "But because the bypass diode doesn’t engage, the whole panel will be dragged down, and it will work at around 20 or 30 watts." And “Because an optimiser is installed, the bypass diode won’t engage to prevent a hot spot. So the entire panel will be dragged down to about 30 watts” My observation from carefully studying V_MPPT is that a Tigo optimizer does also engage 1 or 2 of the 3 bypass diodes in a panel during partial shading. So, I got (the equivalent of) 200 W out of a 300W panel if less than 1/3 was shaded, and 100W if less than 2/3 was shaded. Furthermore, you mention that “Will the string be dragged down because of shade? No. Despite what you have been told, string inverters are much smarter than that.” That seems to depend on the brand. My experience is that a cheap Growatt inverter (S-serie) is indeed that stupid. On the other hand, those Tigo’s were in a split configuration: 2x 335W panels with a Tigo were in sometimes in the shade, and the other 6x 410W panels without optimizer were in the sun. What happened occasionally (and is in line with the main topic of your post!) is that when the 2 panels with Tigo were in the sun, the Tigo’s did not do anything (V_MPPT stayed high, current low) so the whole string performance was dragged down (in combination with a ‘stupid’ Growatt inverter that is). By the way, the monitoring hardware is not so expensive in Europe. It’s about 260 Euro incl. VAT, which is ~400 Aus$.

                                                  TJ Roberts said :Guest Report 2 years ago

                                                  Another powerful article, Mark. Always look forward to them. Looks like Tigo is having their M190 moment... Just got 38 Silfab 360-Watt panels installed on my home with IQ8+ microgrid-forming microinverters. Enphase's Holy Grail is here; their vision has been reached, and they are going to dominate the solar PV market, especially the upgrade business. Microgrid-forming solar PV is going to disrupt the market for sure, especially where I live here in Hurricane Alley — Florida.

                                                    Mark C said :administrator Report 2 years ago

                                                    Hi Henry, The problem with Tigo is they don't have a base in Australia, just a few employees but no ABN. So we need to go to our supplier, which I have done. I'll need to push that further with them soon. Tigo has agreed in theory to replace products that they have approved for warranty. It's proving each individual job that is unrealistic and then fighting overpayment. In some ways it sounds like Tigo's latest response is reasonable and lawful - but - practically it's not. They just need to own the problem and be proactive.

                                                      Henry said :Guest Report 2 years ago

                                                      According to the Australian Competition and Consumer Commission (ACCC) it has an offshoot called the Australian Energy Regulator (AER). It says: "The AER employs the strategy of promoting efficient investment in, and efficient operation and use of, energy services for the long term interests of consumers with respect to price, quality, safety, reliability and security." See Maybe MC Electrical could contact the AER and ask them if they are the body to which a formal complaint should be directed. If they wave their arms and deny all responsibility, they should at least be capable of identifying the organisation responsible. If they try to fob you off then ask the rhetorical question "So, the AER states that this is nothing to do with them, and is unable to identify which organisation does have the responsibility. Tell me, how well do you think that will play out on the front page of the Brisbane Courier Mail? And with a federal election looming, are you not concerned that there will be a heap of pollies who want to keep their seats, and who will just LOVE the publicity that will come from taking a big stick to the AER in the media?" Best of luck, Mark !

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                                                      Mark C said :administrator Report 2 years ago

                                                      Hi Nick, I'm not a fan of the CatchPower hot water diverter (catch blue and green) but we have been testing the CatchPower hot water relay, and I'm thinking it's much better value for money, and it's simpler, so likely to be a lot more reliable.

                                                        Mark C said :administrator Report 2 years ago

                                                        Hi Brandon, I would say Enphase is the best of all "rooftop power electronics" and it's a great product. I also think they are not always necessarily the best shade solution. Check out my recent Enphase tests in this video: --It's also part of this blog

                                                          nick said :Guest Report 2 years ago

                                                          Hi Mark Is catchpower a product that is worth installing on the meter board? is it worth the cost? Thanks Nick

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                                                          Brandon F said :Guest Report 2 years ago

                                                          This makes me very relieved to have gone Enphase on my roof which is subject to shading in winter rather than Tigo!

                                                            Henry said :Guest Report 2 years ago

                                                            "I set up two systems of 19 panels each on 2 Fronius inverters. 5 panels north and 12 panels west. " There may be a mistake of the number 19. It would be 17 I think.

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