I'm an older women who is fascinated with solar. I never trusted data sheets so I really appreciate your testing. Very clear and easy to understand. Thank you so much!
As one who working in the electronics industry as an engineer for over 40 years, I can assure you that a good deal of effort in both characterization and testing in performed on electronic components before they are released for use. For reputable companies like Enphase, Togo and SMA, the data sheet that you seem to dispute was developed not by some marketing guy, but by real engineers who sample a significant number of the product, collect and analyze the data under specified conditions and use statistic to summarize the results with MIN/MAX/TYP values. MIN and MAX values are +/- 3 sigma. You are at liberty to challenge the results produced in the datasheet but I would urge you to contact the manufacturer if you have an issue with the result or the test method used.
As an engineer that worked in Industrial automation industry utilizing inverters (VFD) in very hot environment like paper and steel mills I can assure you that electronic equipment is not happy being hot. I'll bet roof temperature in summer could easily get to 120 to 130 degrees. Personally I'll keep my extra cash in the bank and go with high quality string inverter.
Datasheets are the backbone of all electronic design and the key to maximising efficiency and safety. Without accurate data, it's all guesswork. So, the question you should be asking is "Do I trust the company producing the datasheet?" a lot of cheap imported stuff makes outrageous & unrealistic performance claims, often promoting hazardous use. The secret is to avoid Amazon products with no vowels in the name and stick with brands you know and trust, even if the cost is higher. Burning down your house can be very expensive and losing your life.. well.. nuff said..
There isn’t any inherent problem with datasheets, and it’s easy to spot the rare situation where one is inaccurate or even fraudulent. What the tests in this kind of video are achieving is *system level* performance results based on factors that affect the whole system, especially when it’s only 1 panel amongst an array that is somehow compromised. It’s no fault of the datasheet that system-level performance isn’t reflected in them.
The huge advantage of optimisers is that the DC power that comes down from the roof can go straight to a DC coupled battery and charge it with no conversion losses. This power is additional to the 10 kW limit of the inverter and thereby allows more than 10kW of power to be used by the house if the panels can provide more than 10 kW. As home DC car chargers are introduced EVs will be able to be charged and avoid two current conversion losses.
@@Mavisto2"dangerous" is all about how one manages risk: Clipping, shutoffs, shunts, etc... Unprofessional (whether individual OR "certified" contractor) installation = "Dangerous". Asking EVERY question in depth, even when one thinks one has them all covered is how "Dangerous" is removed from the equation. This is not new tech and the field of managing DC is very mature. It's only when someone decide to be willfully ignorant (ie: lazy about asking) or cut corners on necessary costs that risk becomes high and dangerous becomes real.
Keep in mind that Enphase is also taking their AC reading AT THE SOLAR PANEL... whereas the Tigo / SMA reading for AC is at the SMA inverter, presumably a lot closer to the house utility panel... closer to the loads. Each leg of the Enphase is coming down at 120 volts vs 400+ volts DC for the Tigo/SMA system. So it's not inconsequential... could be another 4 or 5% less yield. Lastly, to get a real reading, you should be using a third party meter for both systems, at the point of connection to the loads. Maybe some CTs could do that.
A very interseting test was done in Europe over a period of 1 year comparing a string inverter with both optimisers and and microinverters featuring real world typical shading (not heavy shading). The result was that there was so little advantage to either optimisers or micro inverters (like 2 or 3%) that you were better off just making up the difference with an extra panel or 2 which was more cost effective. In a heavily shaded scenario there may be a place for these technologies, but once again, they're expensive. A couple of issues with micro inverters : you lose flexibility that you might have with a DC system. ie - you could directly charge a home battery with a DC -DC coverter rather than going DC - AC - DC and if one des fail in the middle of a panel group it involves getting a technician on the roof, lifting panels and replacing the unit.
Yes I have read about that test and you are very right, with no much shade, its best to just remove possible points of failure all together. I also agree with lack of flexibility if using micros when it comes to future battery retrofit. \Thanks for sharing your thoughts and experience on this.
no high DC or arc faults - future proof if panels need to be replaced and that voltage panel is not around and panel level monitoring as your warranty insurance with black start and 25 year warranty available - enphase for the win
I'm still learning but doesn't the micro inverter setup give redundancy whereas the string system basically the whole system or at least one whole section goes off line if there is a problem? That's the big thing people keep mentioning when I look for comparisons between Enphase and Solar Edge, that the SE system can see whole sections of panels go offline when there is a problem, whereas enphase just one panel or even just one part of a panel?
Great video and terrific testing, your customers are very blessed to have an awesome business owner that actually has tested the systems and can recommend the best solution for their needs, keep up the great work you are doing
Back in March 2020, I got 3 groups of 4 panels powered by APS microinveters with a small device that looks like a wifi router that reports the power output through wifi / internet. This small device didn’t cost USD 700, it was in the neighborhood of USD 150 if I recall correctly. It didn’t need a central unit, all microinverters were connected directly to my house’s power panel. Each microinverter takes care of 4 panels, so I bought 3, plus cables. I bought the whole system as a turnkey from a small firm led by a real electrical engineer. In comparison to a centralized system which he also quoted, without optimizer, there was a 20-25% difference. Based on the performance criteria, as it was an investment for 25 years, I went with the microinverters. I don’t know what the prices are at the moment (I’m not in US), but I guess adding an optimizer would decrease the difference, and still 2 issues to be addressed that you didn’t mention: electrical safety and future maintenance. Electrical safety: a centralized inverter with 12 panels in series would amount to 600V, before the AC output which is a hazard (in factories, 440V requires specialized technicians, individual protection equipment, etc), while the microinventers are dealing with 50V in parallel before the AC output, and the 3 inverters are independent from each other. Maintenance: although panels have 25 year warranty, the inventers probably have 5 years (perhaps 10 in some cases). If a centralized inverter goes down after the warranty ends, you have to pay 100% of the system price to replace it, and during that time you get 0% power from the solar panels. In comparison, with microinventers, if one goes down, in my case I will pay 33% to replace it, and still will have 66% of the power. Those are important aspects to consider. My system will have paid back itself sometime this year, I’m paying minimun consuption for my electricity provider, with still 2000 kwh in credit. Water heating included, I moved from gas to electrical. Last point, scalability: I added 4 more panels last year with same type of microinverter, no changes in installation besides adding the new group to the app control. I don’t know how it works to add panels with a centralized system. I did this because I got an EV as a company car, and now I save also on fuel. Best investment in my life, no taxes for the savings (I pay less tax now I my utilities are reduced), and continuous cash flow that will help a lot when I retire.
That’s a good point. I don’t know about every sting inverter, but the two that I have seen have multiple input strings where voltage isn’t allowed over 440V. On my own SolarEdge system, the optimizers (regardless of how many on a string) adjust so that operating voltage is 400V.
@@imnguyen6658 battery system not affordable here. Perhaps in the future. It would cost multiple times what I paid for the system itself. No business case currently
To me the value of Enphase isn’t a slightly better or worse production. It has to do with no single point of failure and proven reliability no other inverter option can touch. Great video!!!!
@@macmierzwa5361 the 5 year warranty is because of the envoy potentially having compatibility issues in the future and Enphase not wanting to be on the hook to create a whole new component to communicate with future wifi or cell signals we currently don’t use. The other aspect is simply the combiner box which you can use a generic sub panel instead if you’d like. When the was the last time a normal electrical panel failed on your watch? I’ve literally never seen an Enphase combiner fail in 7 years
As long as a micro-inverter in the centre of an array doesn't fail and you have to remove many panels to get to the dead inverter. It happened to our neighbour. Absolutely dead unlucky, but it goes to show that whatever can go wrong, will go wrong, with the most inconvenience possible...
Had Enphase inverters installed in 2014. Currently running with 5 dead inverters. Even though Enphase will warranty the inverters, the cost of removing my panel array to identify which ones have failed is simply not worth it. I had 3 systems installed at the same time, 28 panel systems, on 3 different houses. All 3 systems have experienced similar issues. I was gun-ho on Enphase in the beginning, not so much now.
Another great video! It would be important to include a failure rate analysis of both products. This is a big factor for most installers. I worked for Fronius and now work as an Application Engineer for Enphase. At Fronius, we paired the inverter with a Tigo optimizer, and the feedback from installers said the failure rate was higher than other products they installed. Working at Enphase, I don't really hear about any major issues. Once in a blue moon, I do hear that a surge from the grid can cause the microinverters to fail. I would like to get your feedback. I love your videos, keep them coming.
Thank you for sharing! Yes I definitely want to do a video on failure points. It would be interesting to see, especially with Hoymiles making a big entrance.... :D I would go Enphase over any micro anyday, but personally I am more of a string inverter type a gal :D Thank you for sharing your history in Solar
Thanks for all the effort you are putting into your videos to make it digestible. These tests could be boring but you make it very entertaining! Thanks again Martyna.
I am so happy you said that. Thank you so very much for the kind words. I was honestly worried they will be so boring. Next time maybe add a joke here or there or funny facts or sth. :)
The thing that strikes me as weird, is the changing relative outputs between the two test setups (considering only the unshaded panels). And the changing efficiency of the string inverter. At first I thought it might be temperature. That is, as the optimizers warm up they produce less, but later they were back to beating the microinverters. And at one point the string inverter was 95% efficient, and the very next test it dropped to 84%, but later bounced back to 93%. I wondered what sort of load you used, and concluded the simplest and most accurate would be to simply dump all your power to the grid. It doesn't matter if you're dumping 1KW or 3KW (per test setup), the grid voltage should hardly change. So it really comes down to how much the inverter (micro or string) _wants_ to dump onto the grid. Which is a little like an MPPT circuit hunting for the optimal mix of voltage and current to maximize output power of the panel. In the inverter''s case, they might output 239 VAC, 240 VAC, or 241 VAC, and that 0.4% change in target voltage can make a much bigger difference in output current (maybe as much as 5%), which could totally account for the ping-pong performance difference between the two test setups. So perhaps the overall power output difference (because it's so close) is irrelevant. The interesting result is the effect of shading panels on both systems, which also seems close enough to be largely irrelevant. The conclusion I come to is, buy which ever one you want. They're both good.
Hey Scotty, so true and I was also very suprised by the change in the DC to AC conversion. I so wish we could see the DC input of the microinverters, and compare to the AC output. Most major inverters whether string or micro, are similar in the efficiency so its very interesting to see those difference. Just like you concluded, at the end of the day, the homeowner has to decide, since they are both very good! :) Thanks so much for leaving a comment!!! :)
You completely missed the fact the the warranty on the sunny boy SMA inverter is 10 years and will need to be replaced after about 10 years for additional cost. The warranty on the enphase inverters is 25 years and will last the life of the system without needing to be replaced. This would add an additional $5,000.00 (replacing the inverter twice) to the TIGO / SMA system over the solar panel warranty life of the system. I designed photovoltaic systems for 3 years for SolarWorld to include hundreds of residential and commercial systems from 3,500 W to a 1.5 megawatt system for an airport in the Dominican Republic.
May not be reliable info, but I was listening to a paid program by Solar someone. SMA was matching Enphase warranty. I think your comments are valid. 😅
My neighbour is at is 3th inventor in 16 years. The full production was off for one week x 3. If this happens with a micro , you will only loose one panel.
Finally, REAL shade testing! (Like from a nearby tree, chimney, or building, etc.) that STILL allows indirect sky light to reach the shaded cells. Guessing this is a first on all of youtube... Well done.\
@@robertsmith2956EEVblog’s shading issue was without optimizers. That’s exactly the problem optimizers try to solve - and judging by the results in this video, it seems to do it very well
Really nice video, but you didn’t finish the cost vs net gain…if Enphase gives you 3% more - these “savings” offset the extra cost and your pay back time alters? Keep the trials going nice to see real world examples rather than the usual marketing blurb…..
Fantastic video. My system was installed in 2016. There was no such comparison video back in 2016 when I was choosing between Tigo and Enphase. I ended up choosing Tigo and, seeing the results of the video now, I think I made the right choice. I currently own stocks in both companies.
It would be nice to also have seen a full day of non-shaded production. I get the feeling the micro inverter may have performed at least 10% better over the course of the entire day. But i think you are right in your summary in that it really depends on your situation and needs.
@solartimeusa I'm doing research on Solar, and I found that you made one of the best videos on it. No one did this much deep analysis on RU-vid. Please keep it continuous 💐
Excellent comparison video. Easy enough to understand. As an electrical engineer, I REALLY appreciate real world testing. This is first time I've seen any comparison video for solar panels. While I would have loved to see better numerical comparison when comparing AC to DC output for individual panels versus an entire set of panels, the point is not difficult to glean. If you haven't already planned it, I'd love to see the same comparison for batteries; that would be awesome!
Check out neo Volta. I had the 24K installed and it runs my whole house except for the central AC which I keep on the grid because it sucks too much electricity anyway. But I installed 110 volt mini split if there ever was an outage on the grid.
Hi Martyna, love your videos! Thank you so much for conducting such great real life & head to head experiments. Two questions: 1) it seemed like you had pretty significant DC to AC conversion losses on the Tigo/SMA side (10%?). Is that typical or were your AC CT readings a little off? 2) Enphase used to have a lot of reliability issues (compared to Solar Edge for example). But then Solar Edge seemed to have A LOT of problems with their HD series inverters. Comments/thoughts on equipment reliability (as an installer) in 2023? Lots of innovation on the Enphase side. Of course it’s not cheap. Thanks again! Jonathan 12.2kW Panasonic / 11.2kW SolarEdge installed in 1997.
Hey!!! Yes so next test will be Enphase Against SolarEdge. I was personally a bit surprised too at the losses from the conversions. Too bad we can see the DC input on the micros, along with the AC output. That would be interesting to see considering most inverters vether string or micro have similar efficiency ratings. As far as reliability with ENphase, I got burnt years ago, so I am not too trusting of any microinverter, but to be frank, I have not experience a whole lot of replacements in the past 2-3 years, so they must have improved something! :) SolarEdge seems to have a bit more issues, but they ALWAYS replace faulty units and even provide labor reimbursement, which Enphase does not have. I have had a lot of homeowners who bought a home with a pre-existing system, that was SolarEdge, and with no problem they transferred the product ownership to the new homeowner, and all warranty replacements went pretty smooth. So there are pros and cons to both...:) As far as my preference.... I have to be super honest here. String inverter any day.... :( I am very trusting of SMA, even though they aren't as popular... they are made in Germany, and myself growing up in EU, I trust the quality of those products way more than anything made elsewhere. But that could be my Polish-ness talking. Thanks again for sharing your thoughts here, I so appreciate it! Martyna
@@solartimeusa This is a very time consuming test and thanks for doing all that. I was wondering if you can redo only a small subset of the test with Tigo + Fronius inverter, the reason I am asking is that their global maximum point tracking system algorithm is different and in some complicated shade scenarios might produce a different result. Would love to see this but I understand this takes a lot of time and energy to do so.
I have Tigo and SMA and I can confirm that depending on weather conditions you will have around a 5-10% loss in the conversion. You will have less loss on sunny days. For instance I had a day with 98 kwh produced DC and 94 kwh AC. On the cloudy day i had 7.4 kwh DC and 6.6 kwh AC. I don't think her test accounted for the AC losses on the Enphase system as her results were from the micro-inverters not any down line CT's like the optimizers.
Thank you for this brilliant experiment. I have Enphase and I’m happy with the microinverters, but the cost was more. Would be great to see how the iq8+ compares to the iq8a on the 400w panels
@@solartimeusa This was 3 months ago and still no test between the iq8+ and iq8a. I don't know the difference but I think that the plus can be used with more powerful panels.
Thank you for the testing. Most of my experience is with solar panels on conversion vans so relatively smaller systems. I didn't realize that optimizers could help so much with shading challenges
I thought you did a wonderful job! I was also pleasantly surprised that you compared the cost of both systems in the end as well. It appears that the greater efficiency of EnPhase won't recoup the extra cost over the life of the system.
Love your experiments and am looking forward to the other testing mentioned in your replies. I've DIY installed two 4.5k systems on my south facing roof with minor shading. One system is a SolarEdge 3800 and the other is Enphase IQ8m's. Surprised that the Solar Edge has consistently out performed Enphase day in and day out by a solid 5%. It will be interesting to see how your test goes.
Oh wow! Thank you so much for sharing! This is very interesting! What type of panels did you use if you don’t mind me asking? The great thing is that this truly depends on so many factors! Thank you again for sharing!
The SolarEdge install has (14) Canadian Solar cs1k325's. It's almost 5 years old . The Enphase install uses (8) rec365aa's and (4) rec395aa's, it's not quite 2 years old. To tell you the truth, the reason I have this setup is that I was in the process of completely converting to Enphase, but with the performance issue with Enphase I've decided to go a different direction. I'll be adding whole house battery backup and V2H EV charging in the next year or so and right now I'm leaning towards a Sol-Ark 15 with their new optimizers - we'll see.@@solartimeusa
Hey Martyna, you're a natural in front of the camera, I really like these tests, and I don't think you can beat a basic string inverter without optimisers for simplicity, you may lose a tiny bit of production, but for me the less electronics up there the better. PS You can do cartwheels any time you like LOL !!!
Hey Andy, Thank you so much for leaving a comment, I really really appreciate any support! And I am 100% on the same page as you as far as the string inverter goes! :)
What I believe is the most convincing result that you have presented is the substantial cost difference between the two. The other factor to consider is reliability of the two systems. The Enphase unit is really an optimizer (to do maxim power point tracking (MPPT)) and the DC to AC inverter all in one package. Enphase has to put the inverter section up on the hot roof were as the string system the inverter is usually located in a cooler area. Temperature is very import factor when it comes to reliability and the life of components. One of the most temperature sensitive components in electronics are electrolytic capacitors. The inverter section needs electrolytic's to to do filtering of the DC since the AC power is changing from 0 power at the AC zero crossing going all the way up to approximately 1.4 times the power output when it is at the peak power output. This happens 120 times a second for 60 Hertz USA power and 100 times a second for 50 Hertz European power. I once opened up a failed string optimizer and found no electrolytic capacitors located in it. They are located in the inverter. I never open up an Enphase but I believe they have electrolytic's' for the DC filtering. Even so the higher roof temperature still would negatively affect the reliability and life span for all the components which includes for the Enphase the inverter section. Also in the Enphase system the inverter has to be duplicated for each panel this results in not only in a higher cost but due to the higher component count it will effect reliability as well. The string inverter would have approximately the same component count as just one of the Enphase inverter section. In the string inverter the components would only need be larger due to the higher power output requirement. Many installers like the Enphase because I was told in the beginning they offered the installers a generous warranty payment when a failure occurred. I don't know if this is still the case but they more than likely they now stick to what they know. By the way I thought the cart wheel was impressive. :-)
One more aspect to discuss and possibly test is the power loss difference between DC and AC power running along possibly long wires, from one side of the roof to the (SMA or SolarEdge) String Inverter (for DC) or the IQ Combiner box (for AC). Why understanding is that running DC power along 50-100 feet of wire might incur sugnificent power losses, which is not the case with AC power, which makes the conversion from DC to AC closer to the module a better choice. What are your thoughts about that? This field test didn't really test that, since all the wires are very short, which will not be the case in real-life applications, when the panels are spread along the roof area(s) running long wires from the Tigo (or SolarEdge) Power-Optimizers and Enphase Micro-Inverters.
I was surprised the shading test are not comparable with cloud cover. It appears the Tigo system does better in low light. The cloud cover you mentioned was very small. I would be interested in a test conducted across different cloud cover conditions. That will take time to collect for sunny -> heavy cloud cover.
I was the first installer in Arizona to use SolarEdge. Split my 24 panel array of Trina 230's in half and put SolarEdge on one half and the old Zantrex string inverter on the other half. Virtually no shade. Guess what? Zantrex won by a smidge every day. Since then, half the SolarEdges I installed have failed. Would you rather have an ultra reliable array running on a string inverter where you can't see the individual panel results, or would you rather have a much less reliable optimized array that you can easily see the failures?
A thorough, informative video, thank-you Martyna.. Reading about the effects of partially obscuring panels and the effect this has on the different inverter configurations is interesting, academically, but seeing it done helps cement the ideas at play. Plus, your cartwheel was an unexpected little treat.. Keep up the good work..
Thank you so much for leaving your thoughts and sharing. I am sure I could have done this test in different ways or speak about it differently but I hope its a step into the right direction for good product testing. :)
Thank you so much for leaving your thoughts and sharing. I am sure I could have done this test in different ways or speak about it differently but I hope its a step into the right direction for good product testing. :)
A brilliant test and great, very clear video with clear easy to understand graphics, thank you! I have an East/West roof and will fit panels in each direction but a sizeable chimney in the middle to one side (Victorian house) so will have varying amounts of shading over different panels throughout the day! Very interesting!
Great video, glad i went with Enphase 7 years ago, still working just fine! A little pricey but no issues so far, knock on wood! I have a question, can the power optimizer be monitored as individual unit? can you install it yourself provided you feel up to the task, and finally, cost?👍
Just a question at 9:21 Tigo was making 2095w DC and normally the conversion to AC was less than 100w however this time at 9:26 SMA shows 1765w why the major reduction from DC to AC? Again just a question why the conversation not remain within 100w from DC to AC? Is the unit getting hot or something?
Also at 20:43 the math seems wrong 233+18=251 not 241 so thats 6,275 .. also the price difference would be even grater if you used an EG4 6000XP inverter for $1.3k vs a Sunny Boy for $2.4k just saying, however i get the point.
Hi Martyna, I have a video idea for you. From my understanding solar panels advertised performance is based on lab conditions (25C air temp, 1C panel surface temp). This is completely unrealistic and not related to the real world. Panels advertise a coefficient which says how much they theoretically decrease in performance as temp rises, but what does it look like in the real world? If it’s a 95 degree day and the panel is 130 degrees in the full sun, how well will it really perform? You’ve looked at shading etc before but this is even more important. It’s every second of every day. Panels are almost never at lab conditions. So how much will we really get out of them? Thanks.
Your test solidified my choice for SolarEdge Power Optimizers and the string inverter. The difference in cost compared to my neighbors who went with Enphase and micro-inverters is so drastically different I try not to tell them my actual cost....
Thank you Martyna for describing by conducting different tests and arriving at concrete results to decide which may work best in a given situation. I will watch this clip again and again and highly recommend to individual(s) who may have doubts in their heads on deciding which system to go for....By the way that athletic flip was hilarious.
Great video, fantastic comprehensive test. The fact, that covering 1/3 of a panel is as bad as covering half of the panel, comes from the construction of these - usually these are divided into two sections and such covering disables one of them completely. What is more interesting - the power output from panels that are not shaded (let's say #2): - 5:37 - microinverters 159W, string 186W - 7:34 - microinverters 222W, string 244W - 12:15 - microinverters 314W, string 302W - 14:09 - microinverters 326W, string 332W How can we explain this? Does increasing heat affect the optimizers more than microinverters? Also, something very interesting happened at 16:07 - panel #3 without any shadow on microinverter gets 328W, while the one with optimizer only 240, identical to that one with "chimney". Why is that so, especially when at 17:20 it does not lose the power? BTW, was the string inverter in optimal, chilled place? Nevertheless, it is more important how this lasts throughout the years. Microinverters are exposed to extreme weather conditions (heat, cold, water) and this might shorten their lifespan. On the other hand, string inverter works with much higher voltage and wattage, which might also cause failures. But summarizing - the actual differences were really small, and what is important - if you know precisely your lighting conditions, you may install optimizers only on selected panels, reducing your cost even more. However, having optimizers may help with identifying any problems with some panels - without them, you just don't know why your whole string performs worse than expected. And still cost of microinverters is so high, that won't pay off ever. And installing PV is all about money, so... 😉 So to sum it all up: IT DEPENDS 🤣
Very interesting, well done tests ! It looks like the inverter (on the optimizers setup) has huge losses when power is high, what do you think ? Or is energy lost in the cables ?
Excellent video, very informative and real comparation side by side. I know you took the avg price based on manufacturer, but IQ8+ can be found for little less than $200 each, and sometimes $150 each which bring the whole system down to $4.5k I still prefer Enphase, I did a 8 panel installation in South America (where my family lives) and is the best solution, because I can expand the system very easy, and if one microinverter fails, is easier (in my case) to replace it vs the string inverter, besides only one panel will go down instead of the whole system. Another advantage is less cables and only 220~240v max, while with an string inverter, it require DC protections and higher voltage per drop, but the later is a better option if you need a battery backup system.
Lots of efforts to put together two solar inverter systems and carry on the experiments. Thank you for making this comparison video. Also conclusion is also very clear. If during a day shadows come and go on the solar panels, go with micro inverters. If there are no shadow issues, go with one central one inverter and save some money on the equipment. Also get more power in caparison, since no shadow issues.
Is there a difference between them when it comes to hauling the power back to your battery room? It seems to me the micro inverters might save you some money in cable due to the higher voltage allowing a smaller cable.
We have 48x400 W panels on our roof. Feeding into a Sol-Ark 15kW unit. We have not gone with any optimizers since the panels are mostly on the second story roof and unshaded by trees. That being said, one string of eight is often shaded by a chimney stack, blocking its production for much of the day. It may be better to move a portion of those panels to the adjacent rough surface to eliminate the chimney shading. That being said, we still produce over 15 KW when the sun is mostly overhead. Enough to meet our needs by far. I think one also has to look at the additional failure points by adding an optimizer to each panel. Pros and cons. Good video.
Hey! Thank you for sharing your system set up, and yeah you are very right, avoiding those extra points of failure is a good way to go. If you are happy with your system output, that's what matters. anyone can always say:" It COULD be better. BUT its great as is and you're happy with it. :) I love Sol-Arks!
Great video and the testing was very intensive. I have the Solar Edge optimizers installed just a couple of days as I realised later but I think overall with a power production guarantee for 25 years from almost every solar company, it may not be a big difference.
I will be testing SolarEdge against Microinverters soon, but you are correct! The difference is so small, I really don't think you should regret anything, and especially if shading is not even an issue. You should feel good! I like customer service with SolarEdge, they make it really easy to replace faulty units, and are pretty quick about it too!
Good video! Test 11 is more relevant than the other tests which used leaves and cardboard. In real life, panels never see full shading that the cardboard presents, diffused shading from chimneys, vent pipes, trees, and structures is what we actually experience.
Thanks, that was really useful. I wish to point out one small mistake in the costs ( @ 20:49), the IQ8A @$233 plus a Q cable @ $18 = $251, not the $241 which you have shown. Therefore the Enphase system is even more expensive by $250, but that is small compared to the total system cost which is $7008.
Thank you so much for the comment! We used monitoring devices by Tigo, they dont do optimization just panel level monitoring. :) Here is the link to the data sheet etc: www.tigoenergy.com/product/ts4-a-m
Great video! I had no idea about solar in 2015! I got a system with SMA Tripower AND TIGO Optimizers MM-2ES75 for ALL modules. I am so happy since 2015 - NOR the SMA - NOR any Tigo had any fault till current time and contine to work geat!
Great experiments. Thanks! My understanding is Microinverters have a 25 year warrenty, and regular string inverters a 10 year warrenty. Figuring in the need to have to replace the string inverter at least once or twice over the 25 year warrenty on most solar panels (plus installation of it), and the roughly 3% more production of microinverters, the microinverters seem the most long term cost effective solution.
Great video. Would love to see the same test using SolarEdge. SolarEdge is what most EPCs are using along with Enphase. As well, it would be great to see the output by Enphase after conversion from the AC on the roof back to DC into a battery, and then AC into the house as mentioned in other comments.
great points and i have the solaredge inverter prepared to test it, just need to find time!!! :D I agree that would be great to see too. I mayb start asking those companies to send me their batteries to test, because its getting expensive haha!
Bad math. Your calculations should be as follows: 233 + 18 = 251 251 * 25 = 6,275 +733 = $7,008 vs $4,116 What were the make & model of the solar panels that you used in your experiment? I'm curious to know how much actual wattage you monitored vs the STC wattage of the panels. Well done video, by the way. That was a well thought out & well executed video! Ty!
@@solartimeusa Those are pretty high grade panels. I'm a bit surprised that you only got 328W max from a 400W panel under full sunlight conditions (yes I'm aware that you experienced partly cloudy conditions akso, but there were definitely fully sunny conditions too.) 328/400=82% of the STC. Even if the day was very hot, the % loss from high temps would likely be less than 3% of the STC rating. If you measured a higher peak wattage than you showed in the vid, what was the max for those panels?
I am solar permit designer in india and I appreciate your test it is eye Operner for me because I thought there are significant energy dropped in inverter system if there Shadow shade on pv system but there no much different. But in term of costing it is worth. And keep working and testing for ❤(inverter) of solar system. Thank you
Hi, thank you for another great video. I like very much your approach and at min 19:49 you show that Enphase has produce 3 to 3.5% energy. What is also interesting to take into account is when you have battery storage. Enphase will have more current conversion than if you have a DC coupled with Tigo. At the end it would be interesting to see what you get out of your batteries.
This is exactly what I am wondering. Especially for an off grid system that is mostly DC anyway, avoiding those conversion loss's is a big thing. The one time I see the micro inverters as a plus is a grid tie system that does not have battery storage. From all of the research I have done, any system with battery storage in it is better off with optimizers over micro inverters. DC-DC charging efficiency is almost always higher than AC-DC. With solar getting more "common" I hope to see more DC appliance options. There are already DC refrigerators/freezers available, as well as ceiling fans. POE systems are ripe for running off of a 48V solar battery system. That can currently cover lighting, some TV's, a lot of security systems, as well as ports for all sorts of usb devices. Large loads are really the only problem area right now for taking a house completely DC. I am also very interested in building sciences, and believe we have the technology, RIGHT NOW, to be fully capable of building houses that are self sufficient from an energy standpoint, at a reasonable cost compared to current minimum code compliant standards. The biggest problem is convincing people to NOT do the same old thing, but instead do it better.
Great video Martyna, question : if I’ve got a few panels partially shaded each day. Can I add optimizers to just those few panels and improve my entire array’s performance?
One consideration for some may be that micro inverters are subject to EMP destruction (whether natural or anthropogenic) while the all DC PV PNL systems are robust with respect to EMP. Centralized AC inversion within the building structure may of course be remotely shielded. The case for AC of course is made where long cable runs from the PV PNL’s are required where DC I squared R losses become significant. Philosophically I favor maximizing DC thru out the house both for DC reliability and electrical efficiency. This is why Auto, Marine, Aircraft, and electronics utilize predominantly DC. Where AC is required over distance and for AC appliances one must accept the inefficiency of conversion. With AC comes both efficiency losses of conversion and parasitic losses of maintaining inverters operating in standby w/o being loaded. These losses in turn must be alleviated with more PV PNL’s and larger batteries. Martyna, Thanks for empirical testing instead of biased sales pitches. 👍t
As a avid tenter the most important is battery tech so or more videos you test between using different battery tech to see what is the best/and cheapest batteries to use in their systems!
It looks like neither system is a clear winner nor loser. It depends how much shadow can fall on your panels. De difference in installation costs is huge. But if you live in a place with many clouds, trees, buildings etc, over time the cheaper optimizer system might be more expensive. But if you add one or two more panels, it wouldn't make such a difference in initial costs and they could catch up with current lost in shady times. I'm still learning and try to understand, before i decide to start with a system. Thanks for this video, it helped a lot.
A very interesting comparison, thank you. It is worth noting that the Enphase system does not have a single point of failure. A dead Enphase inverter will stop production for one panel while a dead optimiser or central inverter will take down the whole system. A comparison of cabling cost from the roof the central inverter/combiner box would be interesting. AC cabling is mass produced while high voltage DC cabling is more specialised. It would be interesting to compare the AC power reported by the systems with a 3rd party meter.
Great testing, it's likely the most truthfull in the industry keep up with the good work. I have a strong belief in no shading for a roof and a simple layout string inverter all the way. If the roof is chopped up or shaded micro is worth it, and we use AP systems. Finally if it is a ground mounted we only use bifacial panels with string inverters and no MLPE at all.
The SMA / Tigo system is cheaper but they don’t offer 25 year warranty as Enphase. During that time you will have to replace the string inverter of SMA and maybe some optimizers and after that it becomes the more expensive system in addition to being more tedious. Also it will not produce electricity during replacement time. If one Enphase micro brakes down the system will continue to produce electricity.
@@macmierzwa5361 It’s the string inverter that will fail long before 20 years whether it’s an SMA, Solaredge, Fronius etc. In real life however, it has most likely had to be changed for a bigger string inverter after 10 years when adding some more panels. Something, which is not required with microinverters.
I'm not 100% sure but it's most likely that the optimizer modules have built-in bypass diodes. If the main circuitry fails the rest of the string will still function.
@@eDoc2020 I think you are right. If one optimizer fails you will be fine (whole system is not down). It’s the string inverter that is the bottle neck / risk point.
Thx a lot for testing the architecture of the panels by shading them. As one can see the diodes are working as intended. Simple question: what's going to fail most likely, the panel or the electronics? Hence, simple rule, do not build an electronic box per panel on the roof!
Nice comparison, I live in Estonia and get completely different results and the Microinverters are working only from April to September. You should repeat this test in Ohio in a winter month and you get complete different real life results
What do I think? I'm a Brit and your description of a "cloudy" sky is our version of a bright sunny summers day.😂 Secondly the amount of panels you guys can fit on your roofs is probably almost three times more than a lot of houses here.😂 Joking aside, thanks for a brilliant experiment it really helped explain the actual differences between micro-inverters and optimisers rather than the technical ones. After all what is most important to a home owner, how efficient it makes your panels or how they work and why they do what yhey do? Simply how efficient they make the panels in comparison to how much they cost is what we need to know.
Thanks for the informative video. My first thought was to say that a great deal of difference would be seen if you have to place your panel array further from your house. For the string system you would either have to run expensive wire to carry the DC to the house inverter or you would suffer loss. The Microinverters would be much less susceptible to loss since AC can travel further on thinner wire without as much loss (which is why our grid is AC). Your testing of both arrays being adjacent to your building eliminated this from the equation. In my case the array will be about 100 feet from the house.
Not an expert but as she says in the end... if you have a BIG open roof, with no trees, chimneys etc shading - absolutely a string inverter. On my own roof, with a lot of small open places, and V type forms... I think a few panels here and there in different directions with microinverters is the better choice.
It also depends on the quality and tech of the panel and the comparability of the brand inverter. Some panels just go better with certain brand inverters and some clash. As a generalisation premium panels with good micros will outperform a string inverter system with optimisers.
Very interesting, the optimizers seemed to to better at lesser sun levels. A lot of new homes in Australia seem to be long and narrow in profile with often means you may only have east and west faces available for solar. To compensate the temptation is to load up both east and west faces with solar panels meaning at any one time one face or the other will be very sub-optimal in output. My question is in such a setup, shading issues aside which solution ( optimizers/microinverters) would deliver a better combined yield over the course of a full day?
The biggest difference is a micro inverter system does not have a single point of failure, like a Solaredge optimizer system does that feeds into a single string inverter that can fail and shut down the whole system
one extra problem you might wish to consider, is the failure of an inverter, on one Tigo/Sunny boy it knocks out the whole system (stops power generation until fixed and costs a lot to replace, on the enphase system. The loss of just one microinverter is only going to drop 4% on a 25-panel system and isn't hugely expensive to replace and it also does not knock power generation ..this makes the enphase systems huge amount more attractive cost-wise
First thing is I’m new to your channel and ❤the content. My question is : If the panels are facing south, going from left to right wouldn’t the Enphase side get sun first? Would it be the same results if you set the tigo side in front of the Enphase ( far enough in front without shading?). Just curious thank you
Hi Martyna. Great videos! I have few questions thinking of the “ Keep It Simple…..Simple: 1) Do you really need Power Optimizers if you have no shading issues? 2) Regarding the string inverter specification of Max dc Voltage input, is it per String, assuming a more than one String inlet eg a two string invert like a Fronius, or it refers to the total dc voltage input from the panels connected to the inverter, that is to both String inlets together? 3) Can you have a dc side battery connected to the inverter when, only, two separate string connections are available in the inverter and you have a Two String Panel Array System? Is there a separate connection for the dc side battery in a Hybrid Inverter?
Hey there! :) 1. You absolutely do not need power optimizers. They help in situations with extreme shading for sure. The problem becomes when you are in USA, where Rapid shutdown became a code requirement, so you need some sort of roof device to provide that option. BUT Tigo offers also rapid shutdown product that does not do optimization at almost half the price of the power optimizer. But anywhere else in the world, you would not need any panel level device. 2. Yes so depending on the inverter you might have 2 MPPT Trackers, and then 1 string per tracker, but you can check individually based on data sheet. As far as the voltage goes, this also depends on the inverter. Most MMPT operating voltage is 550-600V, and you have to check on panel Voltage to build a properly sized string, without frying it :D DC Voltage in EU is allowed to be much higher even atg 1000V, USA usually is around 600-800V, but definitely depends on the technical sheets. The voltage on those string does not combine. Sometimes you can also add a parallel string, but usually the amp rating is lower, so depending on the panel's current, you have to be careful adding more strings in parallel. 3. Yes so most hybrids will have separate solar inputs and seperate battery inputs. They can operate independently and sometimes people will install solar system with a hybrid but without a battery, and it becomes a "battery ready" system. It operates without battery, or solar, and those can be added at a later time. I hope I made sense :) Martyna
And adding a suggestion: you should test one shading condition at time. The way you did you'll always have a dominant condition that will have the biggest impact. As we cannot compare directly DC vs AC, it's hard to understand the final AC output result.
Great test. Just curious about the efficiency curve of the string inverter. I know that generally string inverter efficiency increases when running closer to maximum capacity. I didn't see you mention the size of the SMA, but if it was a 5 or 6kW then might there be slightly better performance if utilisation was closer to 100%?