441 Are PV Optimizers Worth the Money (e.g. SolarEdge)?

Some of the Y-axes are wrongly labeled (W instead of kW and once V instead of A). But it should be clear what it needs to be.

Really useful! Thank you so much Andreas for thoroughly researching this topic, performing real-world experiments and explaining your conclusions so clearly.

Hi Andreas,
Nice video. I did my PhD on optimizers and PV shading and my conclusions were similar to yours. We also did an article on how to maximize power production of a PV plant by interconnecting the strings in parallel. Passive optimization works about as well as an active one.

Thank you very much, Andreas! We got our PV system installed back in august, and because of your "warning" in one of your earlier videos, I made the last minute decision to cancel the already ordered optimizers - not so much because of their additional cost (I still would have loved to monitor the performance of each module), but more because of the chance they could fail one by one over the years, causing a lot of cost to replace or remove them, especially since they are installed at a hard to reach place. Better to have a reliable, though less performant system for many years, than a little bit more performance with the risk of more problems later on - these modules shall stay untouched on that roof for the next 30 years, if possible. (And saving an extra 900 euros on the invest did not hurt, either... :-)

Personal experience: I pay ~$50 for an SolarEdge S440-1GM4MRM with 99.5% efficiency (as per its data sheet). It's not "just" about increasing the overall performance of the installation, you debunked that quite nicely, but also about measuring individual panel performance. Helps with identifying misbehaving ones.

It would be nice if some research could be done into modelling roof situations to better decide if optimizers/microinverters would be a good solution for special situations.
I think the vast majority of PV installations don’t need optimizers, but there still are a some roofs that might get better yield with them. Whether they are cost effective is another discussion, but to get the best yield sometimes they are needed in my opinion.

Hi Andreas, thanks for this video. Very Interesting to see how well the bypass diodes actually fare. However if you get a chance to resetup the, I think it‘s be if you could run these tests without fully blacked out panels, but with partial shadowing i.e from a net or light - I‘d be interested to see if they help on bypassing clouds or a tree shadow

Great video, as always! One thing that I do like about optimizers: in case of a fire, when you turn off output, the optimizers will drop the voltage on roof so there is less chance of electrical shock to firefighters.
I didn't know about bypass diodes, makes sense the manufacturers implemented that :)

Great observations/tests to make us think about what to install Andreas. Hope you will go more into the use of the battery in the near future.
Just my n=1 anecdote:
I had a 110cm satellite dish on my flat roof that is North-South (about 165 degrees). My PV installation is 10 years old, 1 string, facing almost perfectly south. At just after noon there nearly always (on cloudless days) was a huge drop in my generated power for 45-60 minutes. Power "lost" was about 1 kWh which is about 10% of the daily power generated during summer. In the other seasons, due to high latitude, there is almost no significant loss.
The dish was out of alignement, but I cannot easily access my roof to either fix of remove. When my neighbor installed a PV installation, I asked the installers to remove my dish, not interested in fixing it not watching TV anymore. Since then the drop is gone. Power generated is a nice sine like figure. The dish cast a shadow on 1 of the panels apparently.
Don't know the make or manufacturer of my panels, but I guess they would have benefited from optimizers. But I have a feeling it wouldn't make economic sense to have had them installed.

Great video, thank you for taking the time to experiment and share the results with all of us!

Great video André. I thought i knew a lot about solar panels and optimizers, but this is actually a big thing. Thanks for adressing it.
I think more tests and theory explanation should be done in the following years.
Perhaps the days of the optimizers are counted..
(i myself have 32x 310Wp solar panels, in the same direction, without any shadow and sadly enough all with optimizers)

Thanks Andreas - another fantastic, clear video. I have optimisers fitted in my "professionally" installed system - seems like I fell for the bullshit! One good point about the optimisers (although possibly not making them worth while) - they do let you know the individual output of each panel. Like your brother, I also lost most of the summer's production due to slow delivery of the SolarEdge inverter. I wish I had considered my installation after you, and could have taken advantage of your superb research!!

Very interesting! I wanted a low voltage DC system for a water heater and some 135W half size panels. After fiddling with designs I realised it was more efficient / simpler to have separate optimiser / boost converters on each pannel - with high current / low voltage losses mount up very quickly. It seems to work quite well actually.

That's another great educational video Andreas. Thank you. (Your ESP32 videos have been useful too)
I had watched the NRG video you linked to some time ago and wondered whether I had made a mistake in buying Enphase six years ago. I wanted Enphase because I have panels facing east, north and west (sth hemisphere) and wanted panel level data. I use individual panel data in a couple of automation routines and I also wanted to know if a panel had been damaged or was covered. It did confirm I needed to move a TV mast.
Optimisers were not a thing at that time and while there were inverters with dual strings, I would have had to buy two separate inverters for the three arrays.
You and NRG have now given me a dilemma. I might shortly expand the system to accommodate a battery and sticking with Enphase seemed logical.... but now......

Excellent and eye opening video. I was never fully convinced to micro-inverter idea and it is really nice to see that PV in strings are in fact more robust than the common tale says. Thank you so much!

Thanks for the video. I hadn't previously considered that MPPT may not track to optimum due to shading. Perhaps because I just expect them to work as expected!
Those bypass diodes are certainly worth their weight when used and sized properly.

Interesting video! I recently had my PV installed with a SolarEdge inverter and 2 sets of 9x 370W solar panels with optimizers.
I certainly did have to wait quite a while a while until the inverter for SolarEdge was available. I choose optimizers because 1 set is on the roof of my house and the other is on the roof of my "shed"/parking spot. I also thought I would need the optimizers due to potential shadows of trees a few moments during the day, I guess that was less true than I thought.
Don't know exactly how much I paid for each component, but it wasn't necessarily cheap and let it install by professionals (they already came back to sort out an issue).

Really interesting video ! I have PV solar on my roof for over 14 years now ! In those days, it was rather expensive. But anyway, I'm glad we did it. Now, thanks to your information, I'm preparing a second installation on the roof of my workshop. A work in progress... but defenately very satisfying !

Great video! I’m torn on what to do for my solar project, I’m in the US where rapid shutdown requirements are required. So micros and optimizer systems dominate. The only exception is Tesla where they use simple rapid shutdown modules underneath panels but they don’t optimize, instead it’s done at the string level via software.
I read SMA’s white paper on their own Shadefix solution and I’m inclined to agree, less is better. Less failure points, less heat generated (since no optimizer), and less cost.
BUT, since the US requires a device to rapid shutdown, I’m stuck looking at if I want/need a SolarEdge System with optimizers or if I’m OK going with a system like SMA/Tesla.
I will have different planes, different orientations, etc. For this I’m inclined to believe optimizers can help. But I’m not sure because the way Tesla wires the MPPT for each plane makes sense. One thing for sure I will be skipping Micro personally.
What to do what to do.

This video is why I'm subscribed, real life experiments, a bit of theory to go along with it, excellent stuff!
It's a shame so many installers have no clue how this works, not to mention installers that get bigger profit from installing micro inverters.

Hi Andreas. When I did my research regarding my installation, I came accross an online huawei simulation tool. It allowed me to choose, panels, cables, etc. It also provided the option of adding the huawei optimizers. What I noticed in the simulation charts, is that the inverter started to work sooner in the winter with optimizers. As I understand, an inverter needs a treshold current before it starts? The optimizer would lower the voltage to increase current in order for the inverter to start. This would be interesting in overcast weather.
I asked solar installers for their experience, but no one could help me verify the simulation claim of huawei. I also didnt find anything online about this particular scenario.
Maybe your LTSpice simulation can verify this?
If my simulation charts where correct, the optimizer was a good investment over a couple of years.
Regards,Wim

Great experiment, I had long thought "but what about the bypass diodes?" to these claims.
BTW, I have an Enphase setup, not because I was sucked in, but because my panels are at different angles and alignments, 3 vertical, 5 South ,6 East and 6 West, and that would mean 4 strings, and probably more than 1 inverter... Instead I have no big central inverter at all, which is big bonus to me.

This is exactly what I concluded before installing my panels... but I have roof-surface facing all sides so optimizers seemed a reasonable solution to have west/south/east in a single string.
An alternative would have been a three string inverter and connecting them up separately, but that also creates some problems in terms of wire mess (and these inverters are pretty expensive).
Another possibility would be micro-inverters to east and west, and a simple string south... but again wire mess and on top of that mixed solutions. The price differences for different solutions were not big enough to be the deciding factor.
My main worry is indeed that an optimizer might break, it will be easy to find it but hard to access. 25 years warranty does give some confidence, but the price of the optimizer is not my main concern obviously - loss of production and man-hours to fix it are not covered.

What I have read, optimizer is a good choice if you want monitor status of every single of solar module. It also has safety feature that reduce DC voltage to touch-safe levels and arc fault detection.

great video, thanks for bring this topic up and make it clear. it is ridiculous how some people mislead others in this field
claiming incorrect result relying on unrealistic condition

WOW! awesome video - I confirmed the exact same findings by trial and error when trouble shooting for a bad panel. In defense of the micro's and optimizers - older generations of solar panels probably did not have that pesky diode. But modern half cell solar panels just changed the game completely, they are amazing in dealing with shading. I wish there were more grass roots videos or communities like this, because most solar system installers have no clue about the intricacies of solar installations beyond wiring and city codes, hence the easy way out is to just simply offer a money making stop-gap measure. Good job, man!

Thank you for this analysis, I’ve been sceptical of such micro inverters, they probably made more sense on older panel technology, now I now what to look at for my system, need to Google shadow management now on inverters 😊

Thank you, what an eyeopener. I would only want to point out that with the optimizers or microinverters you can monitor the power output per panel and that is a nice feature if you have to do troubleshooting in the future. Only you need to know the layout of your panels and which is which or you still don''t have any usefulness. But on the other hand, you really have a good point about the active electronics in the harsh environment on the roof during the hot summer sun. What is more likely to break anyway...

This is exactly what I had in mind when I designed our setup, nice to see my theory put to the test!

Excellent video Andreas - your experience and analysis has confirmed that micro-inverters and optimisers really aren’t economic in most applications.

Interesting. I have SolarEdge, but I got a number of quotes from installers and I think all of them included either optimizers or micro inverters. If it was $60/panel, it was about a 5% increase in cost. I can imagine that installers would be right that the marketing value is good enough to justify the costs. Especially with the benefits of individually monitoring panels.

Hi Andreas, I have found a much more significant issue when considering optimizers. They are high power switch mode power supplies and deliver excessive amounts of EMI in the HF bands.If your neighbor is using SolarEdge, check the interference on 20m band during the day. You'll see the noise floor significantly raised with distinctive bands of switching noise throughout the band. On 80M and the lower frequency bands things are even worse. SE optimizers are banned in Sweden due to this. I'm interested to know if you are seeing this interference also.

Micro inverters are maybe not useful in large installations, but in small ones they are a game changer. Not because of efficiency but by pure existence. With micro inverters small installations are easy to install, even by amateurs. Thanks to Micro Inverters balcony power plant are now very common and it will become more and more.

I had a hunch, and I'm glad a channel I know did the same test. I've come across a few videos saying the same thing, that micro-inverters while they technically do something, the cost/benefit might not be as significant thanks to diodes (or good placement).

Dear Andreas,
Hello from Geneva!
I am so happy to have found your channel by accident, i am watching all your video and love them! Thank you for your work and very clear explanations. I really appreciate the fact they debunk the « sales speech » of certain manufacturers such as Enphase but also most video on Clip-Share still encouraging blindly to ise micro-inverters in any situations. (I noticed it especially in french video (in France they still encourage 2-3 kWp lower cost installation with expensive Enphase micro-inverters 😅)
I just made up my mind today to go for a 14kWp 2 strings setup, i will get the Huawei SUN2000 hybrid inverter and get the battery in few years hopefully cheaper. Initially i ordered 6 optimizers (chimney shade) but i will now probably cancel them.
Thank you!

I have had Enphase for a while and one thing I noticed is that with more microinverters the slower the response time on loads. When I only had 10 it would respond fairly quickly when the A/C turned on/off. When I upgraded to 24 there was a noticeable lag on both turn off and on.

Really excellent and hard to find information. There's lots of bad information on the internet (as always). Thanks Andreas! I have been agonizing over whether I made a mistake in not installing the micro-inverters/optimizers. Now I can finally tell my wife WE did not screw up!

Very interesting and thanks for Sharing your results. Bypass diode is the magic word here. In combination with an advanced Inverter (shadow Management). I worked in the PV industry some years back and experienced the rise of these companies. We had cooperations with these companies and also investigated what you showed. We had large Installations where we did what you investigated. I agree that it is not worth the money for a private small PV construction. It is more important to work with an expert to plan and Install the PV modules. Optimize to get the most of it is not trivial and needs good expert. Microinverters have their niche but is not the general solution like you said and showed.

I agree that optimizers aren't really worth it compared to bypass diodes. But I do like the safety aspect of micro inverters. High voltage DC can cause arcs that do not extinguish. It is one of the major culprits in residential solar fires.

When you completely block a panel, the bypass diodes go to work to prevent blockage of the current. (All panels have bypass diodes) The value of optimizers is that they improve current flow during partial blockage. I use Tigo optimizers and they improve my partially shaded arrays power output by about 25%.

What could really help is a system that can inform you, on an app, what cells are not getting unlight. Without that, you have to either go outside and check, or just guess, and it may not be that obvious whether you have one cell a leaf blown over (easily fixed), one that a bird crapped on (a bit harder), or a cloud drifting overhead, which you can't do anything about.

Wow, the technology evolved more than expected in this field. Thank you!

I came to the same conclusion as well. Would be interesting if one could do a scheme using an active mosfet bypass diode to save the diode Vf losse. Possibly built into the cell wafer. Though, it would be strange to tell someone you need to have external control power to activate your solar panel's control circuitry. Where are those zero forward volt diodes when you need them?

Thank you so much! I have two small panels in parallel on my boat, and a very simple (and cheap) regulator. I tried an MPPV system, and it constantly drained 20mA from the battery for its processor, day or night, without providing any obvious benefit. I can't afford 20mA for 24h from my boat battery. I thought I must be doing something wrong. But now I feel I need not worry at all!

The panels facing in different directions problem could also be solved just by having each array direction connected to its own MPPT tracker. this is easy as most inverters now days have more than one tracker built in or in the case of Victron installations extra MPPT modules can be added as needed. Even outside a Victron installation when faced with multiple PV array directions you can just use multiple smaller inverters in parallel to increase you MPPT tracker amount if necessary.

Another great video by you! Thank you for all this relevant information that helps me now know what to expect when this situation arrises and now what to worry about!

Thank you very much for this analysis.
I always asked myself how the cells behave in such a situation, because this year I am planning to built a small solar balcony power plant with storage, where I can only install two panels in very different angles. So I will have very different sources with relatively low voltage and have to figure out the best converter to charge a battery so I can use the power when I am home, which is mainly at dark hours. Schöne Grüße aus München!

Another reason towards micro inverters is, that the system gets slightly more reliable. When something like a Strom destroys parts of your array, your prodution isn't gone completely.
Also a failing inverter is not as much of a problem with bigger setups. And the components are less expensive, as the requirements are lower ;)

Great video! I am planning on installing solar power on my roof, I have about 100 square meters of the roof facing south that can have panels. This gave me valuable information in deciding what to get. Since I'm also into Home Assistant and dabble in electronics, you are my perfect video guru😁. Best wishes from Sweden

Andreas, great Video. Thank you.
As you pointed out, there are situations where optimizers might be worth it:
* Assume a situation where a panel is largely shaded. In this situation, the shottky diodes would bypass the whole panel. This woul not result in the whole string "tied down", but still, this one panel does not produce power anymore. Whith an optimizer, this Panel could still deliver it's small part to the system
* Solaredge Optimizers allow to build very long strings (up to ~11.5kW within a single string), and you kind of don't need to care about elecrical Specs (VOC of the String in cold conditions or the like) or direction of panels. This might facilitate cabling a lot - you need to factor this in for the investment decision
* Solaredge inverters tend to be cheaper than others as they don't need to perform the MPPT anymore - they operate at a constant voltage.
I would be interested in how you "controlled" the optimizer in your test setup? To my knwoledge, you need some Solaredge device to tell the optimizer what current it should produce.
Best regards

Great video as always
Great walkthrough of the problems with EV.
Dave Jones has made a similar problem.
Thanks for sharing your experiences with all of us :--)

Andreas the diodes in the panels bypass the shadowed part of the panel. Always get the right size panels so if you have 400 W keep with that, because going to say a 300W you have a bottleneck due to less current in the 300W panel.

A very intetesting video. As a fellow Ham have you tested the EMI or RF generated from the microinverters? There is a possibility of an RF smog being produced at cirtain times of the day. If true the bypass diodes might be a quieter solution.

At my latitude (42N) I found that South facing and tilted at 60 to 65 degrees was best for winter production while having the least effect on the total yearly output.

Thanks a lot for this series, it’s nice to get a professional and knowledgeable experience.

Finally someone else who did the calculations. All the micro inverter salesmen have been very active lately. I always wonder why they lie about the non-micro inverter panels. Expensive and useless, microinverters are dumb. Also why hang them on the back of a solar panel, where temps often are 65°C. On flat roofs there is access, but on slanted roofs it's a mess if you have to replace a microinverter.

Although microinverters contain an optimizer, I believe the real benefit they offer is redundancy. They connect in parallel.
Thank you for the excellent video. I believe I have watched others of yours regarding antennas and vnas and thoroughly enjoyed those too.

Thanks, very good analysis. What about safety differences between standard installations and one with microinverteras?

Maybe we should have all panels in parallel and use very thick cable or bars to minimize loss and the mppt as close to the panels as possible. What a test, hats of to you Andreas, taking speculation away and making it a real life test with the correct knowledge and measurements.

Optimizers are great for the company that installed your panels, if one of your panels get broken you can see that in de app / on line. So the install company will save time figuring out what is wrong.

Interesting. And as is often the case: keeping things simple gives the best value for money.

Hi Andreas,
I want to share some thoughts.
At least in the Netherlands, 'we' love Enphase and Solaredge. I think for 2 reasons: you have the option to monitor each panel for faults and you can see the yield.
BUT, does that does that outweigh the cost or complexity?
I was thinking of using a normal inverter (DC or AC, according to your needs), but with an ESP32 or similar powerfriendly device in the terminal box behind each panel, feedback via wifi?
If you monitor the voltage over each diode, shouldn't you be able to measure the performance and panel fault? Power the board directly from the panel itself.
Simple and cheap?

Thank you! It's absolutely horrific how much money is being wasted in optimizers!

Now I understand what the shade management algorithm is doing - a more global optimization in the MPPT controller. Older inverters don't have this and older panels don't have they half-cut and bypass diodes, so things are improving!

I've just had another solar installer pull out after keeping me waiting four months holding my deposit! Given the importance and urgency of our current situation it is really disappointing that home solar keeps getting sabotaged by bad regulation, poorly trained installers, misinformation, and a supply chain ridiculously over-dependent on China! I was sold on optimizers because my roof has highly variable shading from nearby trees and also because the panels will be very hard to access so the individual monitoring of panel performance was attractive. I'm now wondering if there is a better way of getting just monitoring. Perhaps just a voltage monitor on each node with radio telemetry? I am beginning to resign myself to designing and at least project managing installation myself!

Wow. So helpful! Love your narration and information. Thank you for your work!

Many thanks for the explanation. We are currently looking at installing 7 PV panels with micro inverters. Your information is extremely helpful.

Hi Andreas, So spot on !! Thanks for the counter balance. Efficiency is key !!
That said, what do you think is the main thing to look at, when you want to maximise low irradiation in winter in Sweden. The time when electrical loads are the highest in the house and PV production is the lowest.
Maybe a higher ( 10-30% ) Wp installed vs your inverter ? An inverter with very low start voltage ? Or a bigger MPPT range of the inverter, or just better of with low efficient panels, as they tend to work "relatively" better in low irradiation. Curious on your thoughts !
Cheers

Nice analysis and testing. Are you still planning to do the “spring update” with the addition of optimizers?

Hi Andreas,
Thanks for another great video.
I have a PV system installed with a string inverter and I am curious to monitor the power performance of each panel individually. I believe that by measuring the voltage increase over each panel, I can get an idea of its performance, as the current is the same throughout the string and can be obtained from the inverter.
However, I am looking for a cost-effective solution to measure the voltage of each panel without having to purchase expensive micro-inverters or optimizers. Do you have any suggestions?
I’m thinking down the line of a voltage sensor that will transmit it readings wirelessly and it should get it’s power from the solar cell minimize cabling. Does such a product exist or is something that needs a maker :-)
Kostal Plenticore plus 10 inverter with two strings used for panels and one for a battery
40 x Jinko Eagle HC60M 310 Wp

You are my hero. I'm in Western Switzerland (NE) and your project is exactly what I've been considering for a while. But it seems most information I can get is superficial or only applicable outside CH. I want more in depth info and you're providing it. Thanks!!!
I have 2 things I'd love you to address:
1. A more in depth video on working with the cooperative. I can't find a good resource showing what to expect and it seems like there are up front costs. Did they buy the panels for you? Do they come with a first assessment? In NE the cost for them is 1000 CHF plus 100 per kWhp. Are there supply issues currently? What is a good time of year to start the project?
2. Does the Huawei system allow you to integrate with IoT? Is there an API? Can I MQTT out the production for instance? The web UI looks great but I'm sure you're like me and want to get the data yourself.

Fantastic video -thank you for the useful insight! Some people have more money then sense - sadly some of these solar installers will believe the marketing hype and happy to accept the kick backs / commissions from these big vendors!

I've been running 12 panels with SolarEdge for 7 years now. Last year I had an optimiser that stopped working. The main advantage of this system is that you can track the performance of your panels. I called the company that installed my system and they replaced the optimiser free of charge (Warranty). 12 panels should give me 3420 Wp but they outperform every single year. Got at least 3800kWh every year minimum. The only thing I don't like is that the main invertor is passively cooled. So I added some PC fans on a timer to cool down the backplate during the hot summer months.

Hi Andreas,
I have a very important observation to the topic, where probably optimizers have an important role! I have installed a Huawei Sun2000-8KTL inverter with 2x9 Sharp 410 PV modules conencting to the 2 MPPT trackers. These PV panels are on a south directed 35° inclination roof in two parallel rows, where I have a tall tree in front. So like a solar clock, the shade wanders around. I was convinced by the installer that no optimizers are needed, along with an australian vlogger, who made tests on different mppt inverters. However! Today the sky is crystal clear, in Hungary, the heating is off, that it warms the house, but the 7.2kWpeak system gives only 0.6kW at 2x310V, compared to a foggy ugly diffuse day few days ago, when I had over 2kW. Also some other day, with clear sky, it happened, that in the morning I had 210V and 9 amps on one string, then jumping up to 310V and 1 A. So, my conclusion is, that if you totally block the light from given areas, then the diodes will bypass, and you get to an optimum, but if you have some partial light, casted by leaves on a tree, it will screw up the mppt, and give low currents at high voltages. I will do observations further, maybe you could test this feature, or we can discuss some experiments and data to see here more clear.

I think your experiment is ameturish at best. The way to truly test the efficiency of optimizers is to have two identical strings (i.e., the same number of panels with the same ratings and the same manufacturer), located at the same location (well, one near the other will suffice). Connect optimizers to panels in one string, and connect the other string directly to the inverter. Now, measure how much ENERGY each string produced over time (e.g., a week, a month, a year) and see which yields more ENERGY. Instantaneous power is meaningless.

Writing from the wet tropics of Australia: Yes I agree the use of optimizers is rarely worth the extra cost. Here we have issues with huge UV exposure and many systems get replaced after just a few years. Bypass diodes are a way to save infrastructure cost and our feed in credit is now so low it is hardly even worth having panels at all.

Thank you @AndreasSpiess for a very good video!
You mentioned that optimizers might help if panels point in different directions.
I have two panels than I'm not using right now. I have 18 panels pointing to SW but no more space to put panels in that direction. But I could place the two unused panels in NE direction and on the same string as the 18 SW panels. Should those two NE panels have optimizers in that case do you think? I feel that the worst panels are the unused ones, but is that always the case?
Thank you again for great video!

Andreass, great job as always! However, I must say that I'm a bit dissapointed... Why didn't you do such a test last year? I wouldn't be persuaded to install the solaredge system, which cost me about 20% more ... :D Well, I'll have to wait a bit longer for the return on this investment ;)

One thing I might add as a owner of a Solar edge installation with optimizers is that it lets me check the output of the individual panels.

Excellent empirical study. Thanks for sharing the results and mith bussting.

Andreas, if I remember correctly, most Huawei inverters allow for two independently optimized strings. In other words, even if you did have 50% panels facing east and the other 50% facing west, you could connect them as two separate circuits, and could still get away without optimizers, right?

I do have SolarEdge system with 14 half-cut panels and all with optimizers. I've got south installation mostly with few of them on the west side. Don't know other producers, but SolarEdge optimizers give me one thing more - safety. When the system is inactive, for error reason or other, optimizers downs the voltage of each panel to 1V/panel.
I have 14 of them so my voltage near the inverter is 14V when you measure DC. It can be even in the full sun at 12:00 on the hot summer.
It will be 14V/DC only, and no Amps that could kill me or burn my house. With that system I also know exact production of each panel in my one string. If there is a bad panel I will know it easily by the panel color intensity in the app.
You can see that on the video below, with timestamp:
clip-share.net/video/30wRG9dgIBc/video.html

You forgot two important advantages of optimizers: Safety and maintenance. Because we installed the system ourselves, we don‘t want to deal with 1000V on our cabling and risk light-arcs every time we unplug something. And we want to see defective panels without having to book a flight with a thermal imaging drone.

My biggest "a-ha" moment in this video was the "shadow-management" local-vs.-global optimum-seeking explained around 13:25 onwards. Once again, thanks, Andreas!

thanks for doing these testing. it is indeed very helpful just may i ask... would it not be better test configuration to go back on the roof and cover actually multiples of the panels on the main string. for example with some large boards or with some plastic sheeting?
it just seems a more true to life and rigorous way to test for the scenario of a greater level of shading, with multiple shaded panels. i mean just to calculate if there are additional losses on modern panels in the first place. not to then bother to try attaching any sorts of optimizers. just merely to determine if then are even going to be any point at all.
this approach would enable testing of all the same type model of panel. instead of using a different kind (of lower wattage). and the ability to cover a more significant total percentage of one whole string. to better try to find some tipping point at which the rest of the string can no longer push the current through so well. of course that is old thinking. on older panels without those shotkky bypass diodes. so perhaps no long applies anymore with modern panels. it would just be really cool to see that! and then completely disprove the whole optimizers for any situations (even the for worst case).
sorry if that seems all a bit much to ask. as i do not want to over step my bounds and be requesting something that is off the table. for example if there is some safety issue, or other practical issues. which would prevent those sorts of tests.
however this is still a great video and very helpful. especially if buying used panels cheaply: to then know to check for this built in bypass feature! also hope your video here will encourage others out there to conduct their own specific testing. whomever else is interested and motivated. perhaps somebody like that marco reps fella (who is putting together a new solar array)

Is there an impact on panel longevity? I read that cells that are covered regularly may have a shorter service life, due to heating concerns.

Thank you for this contribution to such a controversal topic. The YT channel MC Electrical has 2 vids "Fronius vs. Enphase" ca. one year ago with real measurements. Similar did "NRG Solar - National Renewable Group Australia" laso ca. one year ago.
Some percent in difference in practical cases.
I also simulated different parallel vs. serial configurations for older 200W modules using LT-spice. Results were also not soo straight forward.
My 36 PV modules are on the roof now, but I also miss the Fronius und the BYD battery. Maybe next year... we will see. And the switch box for backup island operation has no delivery date up to now. Here we call it DDR 2.0. And do not refer to RAMs. ;-)

Andreas, thank you for your extremely well-structured and comprehensible video. It really helped my understanding. Michael👏

Hello Andreas, good video, thanks for sharing!
I've also had delays in my installation and missed the summer.. I finally I got my 10 kW Huawei Sun 2000 system with battery up and running. I also bought a backup system to run off-grid. The installer sadly didn't install the panels as I wished and I am currently running one string with 18 panels, the other with 12. This unbalance causes the inverter to not run at optimum at low load, PV1 is over and PV2 under 600VDC which adds to losses aswell. Have you considered adding a wind turbine (DC rectified) to your inverter?

many thanks for that honest feedback ! Can you give your view on the wiring size as well ? What the impact of under or oversize the gauge of strings coming from the roof ?

Solar power is really big here in Australia for obvious reasons but most of the installers are dodgy and even electricians don't understand it. I'm about to put a solar plant on my roof so this is very useful.

My solaredge system was installed 7 years ago in a single string split orientation system. 10 west 10 east. As i have nothing to compare it with i cannot know if I fell for the sales pitch. One benefit of the optimizer is that you can see when a panel in a string is not working and get it replaced under warranty. Not sure I would have noticed that one pannel in 20 was only giving about 50% without being able to see the output of each individually. Good video as always.

Do any of you have any thoughts on if optimizers truly make a difference on panels facing different directions? The reason I ask is, I have an extra MPPT on my SolArk inverter that will allow me to use up to 12 of my 85 Voc panels (4 modules in series and 3 strings on that MPPT), but in order for me to max out this MPPT this way, I would have to have the panels pointed in 3 different directions do to space limitations (4 each facing S, E, W). Would placing optimizers on these panels add any significant improvement?

Thank you for this clear explanation. I wonder if electric car batteries which I think are created from a lot of small lithium batteries iin series, also have schottkey diodes inside, to maintain as much capacity as possible, if one or two of those batteries go bad..

No one in the US seems to make (or admit) mistakes these days. You don't learn without making mistakes or failing at tasks... so, why not admit them. Love that you did just that.

Great content - Yet again practical beats "obvious logic" ! 🙂
Yet another great distraction 😞I really should stick to the ESP32 and LoRa videos though or I'll never finish my project! Thanks for your service to this community.

Thank you for your nice video. I am in process of planing my system and I was under the impression that I need optimisers/micro inverters. but from what you said and explained, looks like it is not needed. My only problem is what do I use if I have panels on 3 sides, is that the only case when I would use them ? or just get hybrid inverter with 3 mppt inputs ?

I have personally found that the temperature coefficient and efficiency of the modules, coupled with the quality of the MPPT and efficiency of the string inverter, has far more of an effect on output than many other factors, as does keeping them free from debris. It seems to me that having a string inverter that can monitor the overall performance, and then notify one of general issues is more important than knowing exactly which module is affected.
The typical issue is obvious to the home owner with a visual inspection, and any deeper issues will require a service call anyway. Having a technician spend an hour figuring out which module has failed is only a small part of a service call, and is a cheap tradeoff for better reliability and lower cost by skipping the optimizers. Optimizers will most likely only be worth it when they are built into the module, are as reliable as the rest of the module, don't add cost, and don't compromise efficiency.

So there was a case for optimisers on systems with very old panels but now it is just industry folklore.
Very interesting, shame it is not known more widely.

There is one thing to consider, and that is partial shading of a single cell. My panels have 3 anti-parallel diodes, one diode for every 24 cells. If one cell gets partially shaded, it is reverse biased by the other cells in that series. That can lead to localized heating(often referred to as "hot spotting") of the surface of the cell still exposed to the sun. That permanently degrades the performance of that cell. A MPPT that does not globally scan, means that the string only produces the current of the weakest cell(the one partially shaded) and you lose a lot of output, but, you don't damage the cell/panel. Clearing the leaf, or the bird deposit is all that's necessary to restore full rated power of that panel. The ideal solution, would be a short barrier Schottky diode anti-parallel to each cell. That one cell gets by-passed by its diode, and you lose only ~5 watts of power in that whole string, and the cell is protected, until the panel gets cleaned.
I agree 100%. If all the panels in a string are mounted on the same plane, the losses of the DC optimizers is greater than the differences in the outputs of the panels. Even as they age, I don't think the differences will be anywhere near that 2% used up by the extra electronic modules. They cannot compensate for the damage of the hot-spotted cell caused by the partial shading. the only hope is, to limit the current load on the panel, protecting the cell, but, instead of the whole string being de-rated, you only lose the rating of the one affected panel.