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

Do I need optimizers or microinverters for my PV system? Solar Edge and Enphase, the two most prominent companies in this field, say “yes” and sell many of these little devices. They also explain why they are absolutely needed. But is this true, or are these optimizers only needed to fill the pockets of the manufacturers? Let’s do some tests, compare it with my Huawei Sun2000 string inverter, and learn about modern solar panels.
My second channel: / hb9blawireless
Links:
DIY PV plant playlist: • DIY Solar Power
LTspice Tutorial: • LTspice tutorial
Photovoltaic Cells simulation: • Modeling Photovoltaic ...
LTspice Files: github.com/SensorsIot/Solar-P...
Other videos about the topic: • Micro and String Inver... and • Enphase vs Fronius | i...
The links above usually are affiliate links that support the channel (no additional cost for you).
Supporting Material and Blog Page: www.sensorsiot.org
Github: www.github.com/sensorsiot
My Patreon Page: / andreasspiess
Discord: / discord
If you want to support the channel, please use the links below to start your shopping. No additional charges for you, but I get a commission on your purchases to buy new stuff for the channel
My Amazon.com shop: www.amazon.com/shop/andreassp...
For Banggood bit.ly/2jAQEf4
For AliExpress: bit.ly/2B0yTLL
For Amazon.de: amzn.to/2r0ZCYI
For Amazon UK: amzn.to/2mxBaJf
For ebay.com: ebay.to/2DuYXBp
profile.php?...
/ spiessa
www.instructables.com/member/...
Please do not try to email me. This communication channel is reserved for my primary job
As an Amazon Associate, I earn from qualifying purchases
#no#midroll#ads

[@AndreasSpiess]

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.

[@typxxilps]

not sure but in general our 2022 solar panels and inverters show such string behaviour that 1 partly shadowed module kills the production from about 2500 Watt to 250 Watt and then 30 minutes later the same for the next string which is twice as big from 4500 W to 450 W caused by leaf tree. Each day the same time this can be observed where we moved from 1 bing string inverter to 3 smaller one phase and double string inverters which lead to 6 strings and therefore a much longer usage time of the full power . Our roof is now split into 6 strings instead 1 or 2 and the benefits are significant if you check the inverters string by string and not the inverters in general even though that will show the same effect . If you add a timelapse camera you can mark the lines of the shadow when the shadow is too big for the diodes and the power will be lost. I am not sure about the optimizers but the 4 different Growatt inverters we have had in the past 3 years for tests (like SPH series, 3000-S String, Mic 3000, Min 3000 and Mic 4600). But they also come at a price, which means the price of the purchase of 3 smaller versus 1 bigger but also the lower production cause 6 strings instead of 1 big one means lower string voltages and too low voltages means that the inverter will start later than the 6 times bigger one. 3 Watt is not enough for a 4,6 kW inverter, but 18 Watt sure. Not sure what the shadow optimizer inverter will cost or how big the benfits will be they can gain but it is not that easy. I had played a lot with the simulators like that pv sol premium which Valentin Software offers for free for 30 days but I was able to gain more and more Watt hours by the right inverter size and amount strings and of cause the sting cabling cause our strings are build up vertical cause a tree is spending shadow from 4 pm in the evening which is now not so much wanted than 30 years ago. But it took quite a long time to find solutions for each roof, one with the chimney and the tree shadow and a lower angle while the other has a steeper angle but also its own issues caused by a GAUBE of 7 m widthspan . Gaube looks nice but 22 years later more or less useless nowadays cause a 7 m long segment of the south roof is lost and also causing shadows in the morning and the evening on one or the other side. Hope to see the update video soon, but I guess it will take till spring. Meanwhile we will simply add more panels and another inverter which will help a lot to get the 20 kWp in Spring and maybe in 2 years the 30 kWp as maximum using the roof area better with small microinverters around the 2 chimney and lower areas where the greenhouse is which has a steel roof too. Gets a lot of shadow but 5,5 m width and 2 m depth will offer a spot for 5 big 525 Wp panels that can produce during summer full till 4 pm before autumn and winter will start the time of long shadows no one wants. 3 kWp here and 4 kWp there can make 5000 kWh even in shady situations if the microinverters can proctect these modules close to the chimneys. The Min series from growatt with 2 mppt has helped us a lot like the Min 4600 we could get for 600€ , but the smaller ones like the 1000 W inverters are getting expensive about 350€. Unfortunatelly the cheap chinese GMI inverters or the SGB or many others we have all tested are not really working fully and throttle caused by overheating. Only the more expensive western ones get it done right but at a higher price, lot higher price of about 360€ per 500W - but at least without throttling. Maybe hoymiles might be able to deliver a better performance and having the EU certificates like VDE AR 4015

[@AndreasSpiess]

@@typxxilps Your situation seems to be quite complex! I do not know the products you use. But the inverters must have built-in shadow management. Otherwise, they can react completely wrong (as it is the case at the beginning of your comment). If you need more and more small inverters, optimizers or microinverters might be the better choice, at least for the shortest strings. But still: If a shaded panel does not produce energy, an optimizer will not fix it.

[@uksuperrascal]

Micro inverter and Optimizer The solar equivalent of Batterizer see EEVBlog

[@romanalexandrov2880]

Hi, Andreas! It's been sad for me to see that you don't number you videos any more. It is a killer feature of your channel! Numbers make it so easy to navigate through your vids and I go through them a lot! Let's say I need the video about A6 GSM module, I would simply type 66 in your channel's search and here I have it. I hope you consider keeping on with this tradition! Cheers from Prague =)

[@AndreasSpiess]

@@romanalexandrov2880 I still number my videos. Only the last few get their numbers later...

[@NeilStainton]

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

[@AndreasSpiess]

Thank you. You are ahead of time! This video is not published yet ;-)

[@Conservator.]

@@AndreasSpiess Hi Andreas, Would it be possible to add diodes to old solar panels that do not have them integrated in the panels?

[@AndreasSpiess]

@@Conservator. As you see they have to be placed on the front side. So if you can remove the glad, maybe it is possible.

[@ecolucid]

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.

[@AndreasSpiess]

Interesting paper. Maybe one day they add a few transistors inside the panels to switch each cell accordingly. Because with the current fixed bypass diodes, most of the loss comes from the panel. Which is also lost for the optimizer...

[@ecolucid]

@@AndreasSpiess Thank you for the reply. The bypass diodes are an "economic compromise". When one cell goes on the negative region, its voltage is around -17 times that of the other cells. When adding them up, this makes for a negative voltage that activates the bypass diode. This means that 18 (or around that) are the maximum number of cells you can still protect with a single bypass diode. If I'm not mistaken, space applications put one bypass diode per cell, to avoid this problem and maximize power production. I suppose it would make the PV modules too expensive to do so. :P Transistors would be too complicated.

[@tjunkieu2b]

could you help answer a (hopefully very simple for you) question - adding several higher power (much newer) panels in series with the old ones I should get less than rated from the new addition, but something proportional to the new panel voltage * old panel current right? thank you

[@ecolucid]

@@tjunkieu2b Thank you for your question. I will try my best to answer it. I think you are right: as PV panels age, they produce less current (but not that much less). If you connect a newer panel in series with an old one, they will have the same current for a given point of operation, but they might have different voltages. Would you mind explaining a little more? Are you retrofitting stand alone/DC grid PV for grid injection?

[@GoCoyote]

@tjunkie Yes, but there are issues with mixed modules in a string, and if at all possible one should not do so, or you can significantly shorten the life of the lower power modules as they will be possibly passing more current through them than they are designed for. Best to have the same modules in each series string.

[@bigbronx]

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

[@AndreasSpiess]

My pleasure!

[@stanpak007]

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!

[@AndreasSpiess]

That is what I wanted to show in this video. Microinverters are a good solution for small strings.

[@sorin.n]

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

[@AndreasSpiess]

You are welcome!

[@kozlovskyi]

I'm so glad, you made this KZbin channel. I don't need to know any of that, but can't stop watching :D

[@AndreasSpiess]

Thank you for your kind words.

[@abboberg987]

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)

[@AndreasSpiess]

I currently test optimizers in an arrangement of four panels directing towards south and in a steep angle. I plan to add another 4 panels in the same direction but a different angle. 4 panels are not enough for a string for the Huawei (not enough starting voltage. So I might end up with optimizers in this configuration. At least I will test them.

[@tsbrownie]

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!

[@AndreasSpiess]

So you can be her hero ;-) I am glad that I was able to contribute.

[@tsbrownie]

I also forwarded your video to engineer and architect friends who are working with solar. You are the hero to all of us. Thanks again for your hard work.

[@mohalothman99]

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

[@AndreasSpiess]

I agree!

[@steveatkins2564]

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

[@AndreasSpiess]

Enjoy your installation. Solar is a lot of fun!

[@pimbakkerpim]

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

[@AndreasSpiess]

It feels always good to see that an idea was right ;-)

[@Toxicity1987]

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.

[@AndreasSpiess]

I agree!

[@diatonicdelirium1743]

Very much so: single panel plug and play solutions are up for grabs now.

[@shrujanamsyama9940]

Absolutely. Cost of microinverters for a 3 panel system will be less than a string inverter. In addition, it is easy to install. But if you are going for above 1.5kW power like 3kW or more, they become expensive

[@furmek]

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.

[@yekutielbenheshel354]

You and I are here for the same thing. I frequently encourage Andreas to focus on real world projects because, building stuff well is often remarkably difficult. I also keep encouraging him to use MicroPython on ESP32 instead of C/C++ ESP32 because MicroPython is both quicker an easier to work with, yet often just a performant-from the user's perspective-for many, many projects.

[@AndreasSpiess]

@Daniel: I found out that "Solar" people often do not come from electronics. So they believe their suppliers.

[@yekutielbenheshel354]

@@AndreasSpiess It's "found out" not "fund out". Pro Tip: compose in Google Docs to get grammar checking "on the fly" (automatically).

[@furmek]

@@AndreasSpiess that would explain a thing or two ;) then again installers have access to hardware and putting up a small system to test shading wouldn't take them long but I guess many of them don't care that much. Luckily we have people like you that are willing to spend the time to show and explain how things work without marketing BS and I'm trying to do my part explaining "basic" electrical stuff to my friends.

[@ChrisQPW]

@@AndreasSpiess In the US most of these installers are going to be traditional roofing firms that have added solar to the list of the things they install. As such, will have very little training in the theories and such. I suspect that this would be true of most countries/installers.

[@Nebulorum]

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

[@AndreasSpiess]

You are welcome!

[@michaeldepodesta001]

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

[@AndreasSpiess]

You are welcome!

[@jeremyjedynak]

Great investigation, and great demonstration and use of LTspice!

[@AndreasSpiess]

Thank you!

[@Crypt0Crossf1re]

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!

[@AndreasSpiess]

You are welcome!

[@teuluPaul]

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!!

[@AndreasSpiess]

At least you have a working solar energy factory now. That is the most important fact!

[@wjn777]

Great video and very informative, as always. Thanks for sharing. Happy to see Dishka at the end

[@AndreasSpiess]

You are welcome!

[@doranku]

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.

[@AdityaMehendale]

Did you have "shadow compensating" MPPT? Also, did you have adequate bypass-diodes on your panels?

[@AndreasSpiess]

The forecast of the „optimizer guys in your case would be that you lose the power of the whole string. So if you lost all power during the shadow phase, the chance is that your panels do not have bypass diodes…

[@PhG1961]

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 !

[@AndreasSpiess]

Solar panels are like tattoos: You always want to get another one ;-)

[@PhG1961]

@@AndreasSpiess Can't really tell, I have no tattoo ;-)

[@AndreasSpiess]

@@PhG1961 Me too. But I know lots of people who have a few of them ;-)

[@SolarWebsite]

It's so interesting to see the progression in the PV world. I also started in 2006, with three Sharp 165Wp panels on a Mastervolt Soladin 600 inverter. That system would seem like a toy nowadays.

[@PhG1961]

@@SolarWebsite Mastervolt is a really good brand. We have 10 panels for a total of 2.2 KW with an Infinity inverter. This brand does no longer exist, but it's quite good, so far, never had any issues.

[@mikegofton1]

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

[@AndreasSpiess]

Thank you!

[@fhisg]

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.

[@cybersax2]

Agree. On my installation, one if the panels failed after three months. It was easy to detect as you get power per panel. Our system has 3.6 kWp facing South and 1.5 kWp facing West (both different inclined roof), on one giant string. Hard to say whether this works better than two independent MPPT.

[@AndreasSpiess]

If you value the additional features of optimizers, you did the right choice. I only did not like when salesmen use the "single leave" argument.

[@BrentHeberAusNZ]

Exactly, this line of “optimisers are all about shade” is typical of string manufacturers. It totally misdirects from the many other benefits of MLPE like many safety features, panel level visibility, simpler fault detection and repair work, higher efficiency, dc coupled storage, the list goes on. Making it all about shade, which is a confusing topic and difficult to properly compare, makes it simpler to push the traditional dangerous string inverters with uncontrollable high voltage dc.

[@johnthomas338]

@@cybersax2 Solar panels hardly EVER fail nowadays. Quality control is so good.

[@johnthomas338]

@@BrentHeberAusNZ Ooh, dangerous string inverters! It's still the same amount of kilowatts coming down the string, which will still kill you, whether DC or AC. Who needs panel level visibility? What fault detection. Solar panels almost NEVER fail nowadays.Higher efficiency? Any proof of this?

[@yekutielbenheshel354]

Yeah! A video about a real world engineering project! Thank you Andreas!

[@AndreasSpiess]

My pleasure!

[@haukewalden2840]

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... :-)

[@AndreasSpiess]

I added a simple "divided by the number of panels" in my Grafana board. Now I can compare the cells and see if one creates problems. The only thing is that I do not know which one it is ;-)

[@Senthiuz]

Pretty much everything I've read and watched about optimizers says they are a waste or worse in most situations. Unfortunately, since the US NEC 2017 & 2020 electric codes require Rapid Shutdown on a per panel basis, the math changes a bit. If you already have to put an additional RSD module on a panel, maybe putting on optimizers with RSD and monitoring instead makes more sense since you are no longer adding more connections or modules in the chain.

[@alexanderkirchnerat]

Thank you for this great video and your tests. This is exactly my situation and answers my questions! Greetings from Vorarlberg!

[@AndreasSpiess]

Glad the video was helpful!

[@Rei_n1]

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

[@AndreasSpiess]

You are welcome!

[@Zothaqqua]

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!

[@AndreasSpiess]

20mA indeed is not a lot for solar power systems where we try to produce MWh. But in your case, maybe it would be of benefit to find a space for an additional panel. This often is the better way.

[@greg4367]

Hi Andreas and greetings from San Francisco. Thank you, you just saved me a bundle.

[@AndreasSpiess]

Cool! Sleep well. It must be late!

[@PlanetCypher_]

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 😊

[@AndreasSpiess]

Good luck with your system!

[@keithcress1335]

Thanks for this! I was just contemplating optimizers. Dishka looks very content. :)

[@AndreasSpiess]

Glad it was helpful!

[@Beeeeeeeeeee]

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.

[@AndreasSpiess]

Microinverters are ok for small systems with only one or a few panels, I think (we call them "balcony power plants").

[@OldCurmudgeon3DP]

Thanks for the info. The cat was a nice touch at the end.

[@AndreasSpiess]

You are welcome!

[@FrankGastelum]

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

[@AndreasSpiess]

My pleasure!

[@catcam]

Thanks for that dear Andreas. I see Dishka is in good shape still. All the best from Croatia.

[@AndreasSpiess]

Yes, she is still happy…

[@dmurphydrtc]

Excellent video Andreas. Thanks.

[@AndreasSpiess]

You are welcome!

[@janisvaskevics93]

Grwat choice of subject! Also, superb meticulous approach, as usual.

[@AndreasSpiess]

Thank you!

[@Chris-ie9os]

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

[@AndreasSpiess]

You are welcome!

[@electronics.unmessed]

Good analysis and explanation, I also like the simulation! 😀😀😀

[@AndreasSpiess]

Thank you!

[@4257stefan]

Very good video and absolut refreshing english while pointing out very clear the opinion

[@AndreasSpiess]

Thank you!

[@portfedh]

I missed your videos. They are great!

[@AndreasSpiess]

Thank you!

[@TrevorFraserAU]

Very good, thanks for sharing your experience!

[@AndreasSpiess]

My pleasure!

[@danielharp5883]

Interesting video! Got recommended it on YT.

[@AndreasSpiess]

Thank you!

[@alvingallegos6367]

Thank you Andreas!

[@AndreasSpiess]

My pleasure!

[@nutsnproud6932]

Thanks for the video Andreas. I giggled at the 15 o'clock and my cat ran off when she saw your cat.

[@AndreasSpiess]

Sorry for scaring your cat;-)

[@MikeKasprzak]

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).

[@AndreasSpiess]

Microinverters are a good choice for small systems, I think.

[@andreaslingelbach7830]

Great video with much content details 👍🏻👍🏻 Thanks for your research. Greetings from germany

[@AndreasSpiess]

Thanks for watching!

[@avejst]

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 :--)

[@AndreasSpiess]

Indeed, Dave went a slightly different way with two independent systems (one string inverter and the other micro inverters).

[@bennylloyd-willner9667]

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

[@AndreasSpiess]

So enjoy your project! We love it even if it does no more cover our full needs because of the weather and the low sun.

[@shrujanamsyama9940]

That is a pretty big roof considering it is just one side! You can place 10kW panels easily on it Depending on latitude, climate and shading, you will get 30-50kWh/ day on average

[@conglin6965]

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 KZbin 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!

[@AndreasSpiess]

Welcome aboard the channel! For small systems, microinverters might be a good solution because string inverters usually need a certain startup voltage. For your large system, a string inverter is a good choice.

[@TheDexboy]

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 :)

[@BBru062]

Yeah its a good idea on paper, but an incorrect installation, a factory defect, or like in most cases a bad connector tend to start these fires. Connectors failing are one of the leading causes of fires and when adding optimizers you triple the amount of connectors in a system. Not to mention that not all systems are equipped with such devices and they can fail closed leaving the system still energized. So in the end you have to train for the worst case scenario and treat each as it is live. The real solution would be to integrate into the panel but I don't see module manufacturers wanting to do that.

[@AndreasSpiess]

I do not know how dangerous it is for firefighters. As always, you have to hold both ends of a "battery" in your hands to experience a shock. Reading through recommendations for firefighters in this case, they list various things. None of them related to be electrocuted by the panels.

[@lne176]

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!

[@AndreasSpiess]

Thank you! These diodes seem to be the standard for the last 10 years.

[@baranjen]

Fantastic video. Thanks very much Andreas

[@AndreasSpiess]

My pleasure!

[@tifendro]

Very nice analysis !

[@AndreasSpiess]

Thank you!

[@ds94703]

Very well done.

[@AndreasSpiess]

Thank you!

[@someonesays8022]

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...

[@AndreasSpiess]

Single panel monitoring seems to be important for many people. Professional installers know that panels do not fail often…

[@shrujanamsyama9940]

The monitoring is a nice feature but not needed. Even without it, the panels will function the same. Even if you manage to find out that 1 out of 15 panels is defective, the cost of optimiser would have been much more than the cost you saved by getting 1 panel replaced

[@klassichd10]

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. ;-)

[@AndreasSpiess]

Thank you for the hint about the Australian video. I thought I had it included in my comment, but I forgot it. Now it is there. And good luck with your inverter and battery...

[@Zonker66]

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.

[@AndreasSpiess]

I agree. You only learn with making mistakes. If you get it right, you already knew it before ;-)

[@John_Smith__]

Yet another excellent video.

[@AndreasSpiess]

Thank you.

[@tjwatts100]

Wow. Such an informative video, as always Herr Spiess 👍😃 I bet a few "fancy add on gadget" companies will not be happy now 😄

[@AndreasSpiess]

I think they know these facts, too…

[@Steve61]

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......

[@AndreasSpiess]

I think you did a valid decision. This video is only focusing on one wrong claim of the industry. Your microinverters still work. So let’s hope this will continue for the next 18 years.

[@IndependentNewsMedia]

Great video, keep up the good work 👍

[@AndreasSpiess]

Thanks, will do!

[@BerndFelsche]

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.

[@ChriFux]

the inverter tracks to the maximum global mppt, but obviously can't step up or down single panel voltage

[@AndreasSpiess]

If you look at the U-I diagrams of the panels you see, that the panels adjust voltage according the current. This effect is used by the MPPT.

[@n1vca]

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!

[@AndreasSpiess]

In your situation, I would go with microinverters.

[@hoofie2002]

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.

[@AndreasSpiess]

I also learned that it is good if you know the topic ;-)

[@peterclarke5323]

That's saved me some money. Thanks.

[@AndreasSpiess]

You are welcome!

[@Poekieman]

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

[@AndreasSpiess]

I agree!

[@Luke-san]

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.

[@matthewmaxwell-burton4549]

Having them in parallel isn't perfect either. A shaded solar panel can become a current sink without a blocking diode. Although counterintuitive because a solar panel is a diode, it's only a very weak one and reverse current can cause it to fail. Moreover, the thick cables will cost a lot more than having a mini inverter behind the panel and using classic 230 cabling.

[@Luke-san]

@@matthewmaxwell-burton4549 I agree and value the response! I have a mix of different 18V max mppt panels just for testing. I actually wire them up in parallel with a Schottky diode in series of each panel. I know not 100% efficient but there is a best approach which each situation.

[@AndreasSpiess]

With small panels, maybe more arrangements are possible. If you work with higher power you have to take the capabilities of the inverter into consideration. I like if my inverter and battery use high voltages because it generally reduces loss and reduces the needed copper.

[@gorgonbert]

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.

[@AndreasSpiess]

I agree.

[@thomaswomack3888]

as someone new to solar and trying to get up to speed you have helped me a great deal. All our panels are on the same southern facing plane of our roof and therefore microinverters are unnecessary but yet the company doing the install has used them. We will be questioning their usage and likely asking for their removal since they are ineffective and expensive. And requesting the appropriate price reduction according to their cost. Our situation is something of a nightmare, a company that takes advantage of its customers by being greedy, and overly accepting of what the equipment providers ad copy says. I dont buy half of it, and am becoming increasingly antagonistic towards my installer for that very reason. If we don't end up in court it will be a minor miracle. Thank you again for your common sense approach to this. I am very grateful.

[@AndreasSpiess]

Many installers are also "cheated" by the suppliers. Keep in mind: This is a growing market with many new entrants without deep knowledge. I would inform your installer, not punish him.

[@uwezimmermann5427]

Thank you!

[@AndreasSpiess]

You are welcome!

[@remy44444]

Very informative, thank you.

[@AndreasSpiess]

You are welcome!

[@MarkAAshdown]

Very good video- thank you.

[@AndreasSpiess]

Glad you liked it!

[@CarstenDressler]

Good stuff! Great explanation

[@AndreasSpiess]

Glad you liked it!

[@MaximSraj]

Thank you for the great content!

[@AndreasSpiess]

You are welcome!

[@stephang5671]

Great, thanks!

[@AndreasSpiess]

You're welcome!

[@Abc-sl1nf]

Great and helpful. Thank you!

[@AndreasSpiess]

You are welcome!

[@AdityaMehendale]

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!

[@AndreasSpiess]

You are welcome!

[@AdityaMehendale]

@@AndreasSpiess Dave from EEVblog did a video about a similar topic, kzbin.info/www/bejne/d5PbeaKHe5l0es0 - i suspect his older inverter was not equipped with global-MPPT.

[@AndreasSpiess]

@@AdityaMehendale I saw this video, too. It must be something like that. I assume bypass diodes would not have kicked in with this small shadow.

[@peter.stimpel]

messing with the industry telling you should spent your money ... I like it.

[@AndreasSpiess]

I thought it was necessary. We should at least know the reality before we decide...

[@richard--s]

@@AndreasSpiess yes! Good decision to make this video!

[@kitecattestecke2303]

@@AndreasSpiess truth must be told, the true duty of the enlighten! Thank you for the video :-)

[@tolsen4893]

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.

[@AndreasSpiess]

Glad it works. I did not say, it does not work. I said it is not needed...

[@tolsen4893]

@@AndreasSpiess Yes sorry I didn't want to imply that! One thing occurred to me though.. for most applications isn't the selling point of the optimiser to convert directly to 230V AC at each panel? Not applicable in your own case, but I could then understand that it would shift and break up total losses from a central inverter to each optimiser so not quite as bad!

[@AndreasSpiess]

@@tolsen4893 These "optimizers" are called "Microinverters" (also covered in the video)

[@tolsen4893]

@@AndreasSpiess Ahhhhh! Sorry that makes sense!!

[@ravisharma9683]

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!

[@AndreasSpiess]

Most of them are not specialist. So they go with what they are told :-(

[@BladeBloodreaver]

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).

[@AndreasSpiess]

I would not look back because your PV works. This is for people who have to decide and I wanted that the are not cheated.

[@wktodd]

Great thanks Andreas

[@AndreasSpiess]

Glad you liked it!

[@juststeve5542]

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.

[@AndreasSpiess]

For those setups, micro inverters are a good solution. Particularly for short strings.

[@chuxxsss]

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.

[@AndreasSpiess]

I agree! Injustice tried to do all possible errors ;-)

[@ByToothandClaw]

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.

[@AndreasSpiess]

Indeed, these are two different topics. But I know that a lot of "Makers" these days added "Solar" to their topics. Also because they sometimes are asked by their colleagues about their opinion.

[@ByToothandClaw]

@@AndreasSpiess a lot are probably interested in building solar as well! Including me. Just not enough time! :-)

[@jamesmichener7526]

A fantastic video! The best solar optimizer is to take cash used to buy optimizers and buy 30% more solar panels! Being a fellow amateur radio operator, the last thing you want are a bunch of poorly made switching supplies on your roof connected by a long antenna.

[@AndreasSpiess]

Indeed, like with motors, displacement is best replaced with more displacement ;-)

[@jamesmichener7526]

@@AndreasSpiess The saying in the US is. 'There is no replacement for displacement' ... :->

[@timh2870]

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.

[@AndreasSpiess]

You are right. If you optimize for winter, south and steep is best. I added a few of those, too.

[@LawpickingLocksmith]

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.

[@AndreasSpiess]

You are lucky you are far away from Europe. Here, energy currently is a very hot topic ;-)

[@supernumex]

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.

[@AndreasSpiess]

If other criteria are important for you, your decision was perfect. This video was just one claim often made.

[@qcsupport2594]

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!

[@AndreasSpiess]

Definitively they are improving! And it is important that we know what it means for us ;-)

[@thomasblock3117]

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.

[@AndreasSpiess]

I currently play around with microinverters as a "balcony power station". They are fun for one panel and very easy to use.

[@diatonicdelirium1743]

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.

[@AndreasSpiess]

I agree, in some cases optimizers are good. I am not against them. I just wanted to show what is true and what not. Then my viewers can decide..

[@diatonicdelirium1743]

@@AndreasSpiess And your work is appreciated. So many options out there gives a lot of space for installers to 'peddle' expensive solutions - information is key!

[@ChrisQPW]

Personally, my biggest concern would be if the company will be around when a failure happens, not to mention if the part will still be made at that time.

[@diatonicdelirium1743]

@@ChrisQPW Indeed, the implementation of any warranty beyond 5 years is always a bit of a question mark. My house is about 17 years old now and some things are starting to break (as expected)... good luck finding *new* parts to repair anything!

[@shrujanamsyama9940]

@@diatonicdelirium1743 Yup, older parts are very difficult to replace. It is always better to buy standardised unbranded/generic items which will remain standard for long time than buy fancy branded items which keep getting upgraded!

[@bnk28zfp]

thank you!!!

[@AndreasSpiess]

You are welcome.

[@rickharold7884]

Totally awesome

[@AndreasSpiess]

Thank you!

[@jorgeferreira2009]

Extremely interesting this post of yours. I guess that common mortals like myself trust it when they say "You have to have it" but now I ask ... do I really? Thanks to, at least, planted the bug and make me research this more deeply.

[@AndreasSpiess]

Research and open eyes are always good ;-)

[@bnk28zfp]

for long time i was looking some one compare it! and yes i decide do not use those! thank you Andreas!

[@AndreasSpiess]

You are welcome!

[@irgendoepis]

Sackstarch... Ich hoffe du lehrst an einer berufsschule oder fh eltech. Du erklärst sauber und extrem verständlich. Habe viel aus deinen früheren videos mitgenommen. Danke das du dein wissen teilst.

[@AndreasSpiess]

Vielen Dank für die Blumen ;-) Ja, ich habe früher an Unis und Fachhochschulen unterrichtet.

[@za8heartnet11]

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.

[@AndreasSpiess]

You are right. Keep in mind that after a few weeks, most users only check the power every month or so. And only for the whole plant and a whole day... The risk of having electronics in the heat and humidity of a roof stays forever...