* NOTES SINCE PUBLICATION * Some people have asked if this video was sponsored by Enphase. I can confirm it was not, and that I received no monetary or other benefit from Enphase for making it.
Hi Gary, I just read through the comments below this video and I'm sorry that you're receiving so many hateful comments, while all you're doing is trying to educate us on solar. Hopefully these comments don't discourage you to create more videos, as there are also many people (like myself) who learn a lot from them. Keep up the good work :)
Hi Renske, thanks - yeah, I guess this is the world we live in now. It doesn't matter how well-researched the content is, there will always be those who have something negative to say about it (always far easier to critique than create). I don't worry too much about it - and RUclips gives me enough control over any comments that cross the line... Judging from the overwhelmingly positive feedback I get, I think my content is very welcome, so don't worry - I'll keep the videos coming :-) I really appreciate you taking the time to raise this!
Hi Gary, After several years of pondering and researching, and many RUclips videos including your excellent productions, I have finally taken the leap and placed my order for a 7KWp solar PV with Enphase Microinverters and Givenergy 13.5KW AIO battery and gateway. I really like the flexibility and redundancy that Microinverters provide, along with better warranty and detailed panel-level power generation telemetry data - all discussed in your excellent video here. Thanks for all your great work!
Apart from remote monitoring and optimization, what differences are there between micro inverters & parallel pv string connection paired with hybrid Mppt inverter, especially for an array below 5kw.
Feel free to come on and tell us in 20 years, (way past the targeted technical lifecycle of an inverter) how 1 dies every year, requiring expensive work on the roof. Warranty is all fine and dandy, but max technical life of a panel is wayyyy byond 30 years, thats multiple times the max technical life of the inverters. Roof work is expensive, you will come to realise that in 15-25 years.
@@gozieanyiam7169 The fact you will require roof work for every one of these things breaking down. Every-single-time. The lies in metrics Gary is showing here, are not relevant. Obviously they dont fail in 7 years. But their lifespan is FAR FAR shorter than the 30, 40 or even 50 years your panels can just lay-there without replacement.
@@kjeldschouten-lebbing6260 believe it, parallel pv string connection with the necessary protection systems beats micro inverters (price-wise & in reliability)
After about 2 years of searching for a solution to my mottled winter shading problem (and humid environment) I can finally make a decision. Thank you so much Gary.
MicroInverter Ecosystem Questions: I have been wanting to understand Understanding Micro Inverter Ecosystems for a long time. Unfortunately no one explains in detail this type of inverter ecosystem. Your explanation is great, but: Here are my QUESTIONS, for your future videos, or to answer in a reply: 1) when you daisy chain multiple micro inverters onto the backbone wire, how do they stay in phase with one another? 2) when you have multiple runs (backbone runs) how does each run stay in phase with the other runs? 3) how do you wire multiple runs into an AC breaker box, to then be distributed for use to the house or building? 4) How do you store energy from these micro inverters which output 240V AC into a DC battery bank? 5) how do you get energy out of the battery bank and into the AC Breaker Panel, and keep it in phase with the input from the micro inverter runs? 6) How do you get Split Phase out of each run and maintain sync across multiple runs, and how to wire split phase into the breaker panel from multiple runs? I have more questions, but if you could answer those in depth, it would be greatly appreciated. Thank you.
Hi J K, thanks for taking the time to comment, and also your questions. I just don't have the time to answer them all (or the next batch of questions you have coming), I'm afraid. Perhaps others can...
One thing you didn't mention is the possibility of fitting the microinverters INSIDE the loft space. This is what my installer recommended in 2017, and they did a very neat job of it. I had an inverter failure recently (Enphase), but I was sent a replacement quickly free of charge and an electrician friend just swapped it over for me in a couple of minutes using no more than a screwdriver. There is an added benefit in that you can swap two inverters over to work out whether a particular inverter has failed or the panel attached to it has failed. The Enphase microinverters flash when they're generating AC, so you can spot a failure easily, without having to check through all the serial numbers. Thanks for your channel - it's really well done and very informative.
I didn’t mention in the video, but it did come up in the comments after release. Assuming no leakage issues, it doesn’t sound a great way to manage the risk of any failure 👍🏻
I am embarrassed to say that I had accepted the myth that only those that qualified for the old feed in tariff saw the return on investment! I wish that the people running the country adopted the same level headed no nonsense approach. You have my vote Gary and hats off to you.
Hi Barnaby, you're too kind, but thank you. I agree though, that this country (and many other countries) are run by people who don't necessary have a good grasp of the issues at hand, or how to effectively deal with them.
@@GaryDoesSolar One of the issues that leaders have only JUST cottoned on to, is that ROI is only a small part of it If every single house had solar panels, including those that face north, we'd have a lot more solar output going back into the grid, whilst making things cheaper for people as a whole The few billion in debt in the short term pales into comparison to the returns. The biggest returns for a country are : Energy security Grid resilience I've only really realised after I got solar panels, that my solar panels are essentially an extension of the grid because it still has to talk back to the grid. For this reason, if the grid isn't working, the solar panels also don't work. Batteries however would work Being decentralised helps in terms of say anyone wanting to bomb energy infrastructure. We'd still maintain some form of centralisation via the national grid ofc
I've had an Enphase system with Micro Inverters and a Tesla Powerwall for the past 3 years and would never go with a central inverter due to a single point of failure you pointed out. I'm in Las Vegas NV and have produced 38.5 MWH over the past 3 years, when I return to the UK and put solar in, I will certainly be using Enphase Micro Inverters again. A friend of ours had a single inverter and did not realize for 2 months it had died and their system did not generate power for that period!
Thanks for sharing your microinverter experience here. Wow - that's a LOT of generation, but perhaps in LV, that's to be expected :-) Will you get a chance to go to a show in The Sphere before you return to UK? Something I'd love to do!
I have 23 IQ8+/IQ8A micro inverters and that is the way to go. So simple to add more. All plug and play. You can even commission them yourself if your a DIY guy. My neighbor is an electrician and I just mount them all up and he makes the final connection which is as simple as adding a breaker to the combiner box and connecting two wires. Even a caveman can do it. I think the hardest part of adding more panels was running the conduit/pvc and pulling the wire. Time consuming but not hard. I love micro inverters. Nice video!
Cheers - you might also like this interview I did with Enphase too: ruclips.net/video/kGCKarB7fnI/видео.htmlsi=RiYZ0NwX3P1JhOGt There's a lot to be said about Microinverters :-)
Got a 5kw system installed about 10 yrs ago with micro inverters, never had any trouble with the system unlike our previous house where the big inverter died after 5 years.
Hi Steve, thanks for taking the time to comment. I think there is huge fear of microinverters failing all the time, when the reality (and the stats) show otherwise.
@@GaryDoesSolar In reality, almost no one actually has them close to their est. technical lifetime. So you cannot say that at all. Thats not valid statistical work at all. Nice and all, but if the technical life is 15 years and after that time one dies every year, the costs are not funny at all. Whereas a dead string inverter is a 2 hour switch-job at best.
As someone with a real-world micro-inverter solution, everything that Gary has said makes utter sense. I have 31 panels with 10Kw potential generation spread across East, North and West elevations (Australia). Shading issues would render a string based solution mostly useless, instead I have reliable, predictable generation. I have had zero failures, zero downtime in the 4 years since I had the system installed. I use a Blue Catch intelligent diverter to power hot water from solar. I will be adding some more capacity and a Tesla Powerwall to the system shortly. It will give me backup protection and combined with Tesla's VPP, I can expect minimal bills. I prefer the initial cost disadvantage in the knowledge that reliability, longevity and TCO will make micro-inverters the better choice.
Thanks for sharing this Nick. All too often, all people see are complaints when solutions are not working, and this leads to a strong bias against (a bit like looking at hotel reviews, where a 99% positive rating across 5,000 reviews might be discounted heavily because of 2 or 3 bad reviews). It's great to see that your micoinverter solution is working well :-)
@@GaryDoesSolar , I have a question about the failure rate calculation in the video. You show up in the first sample 3100 MC installations in 5 years by 3 failed modules. Would be a rate of 3/3100*100=0.0968% and in 25 years 5 times this=0.484% assuming a linear propagation of the faliled modules while the reality would be more steeper increase. Can you clarify how you got to the failure rate of 0.064% in 25 years? The concept of enphase is nice but has also disadvantages. They are expensive. Some Inverters have also waranty up to 25 years and even if they have only 10 years, in general they last 15 oder even 20 years, before they need to be replaces, which is much easier end less expensive than replacing the MC on the roof. The string size with enpahse is limited to 16 or 19 modules. You need the controller and additional rellais, which all needs housing and wiring. And also bad is, that the akkus are very expensive and you are bound to enphase. In practice, because of the bypass diods and the shadow management, you have not that advantage they claim.
@@loukili63 It's been a while since I made this video, and so I'd need to dig out my notes for the calculation methods, but for the 3,100 sample, the important thing to remember is that number of units grows from zero to 3,100 over that time, so I likely used the midway point as an average (i.e. 3 units failed out of a notional 1,550 units operating for the 5 years). Then I would have calculated the probability of survival over the same 5 years, before extrapolating that out to 25 years (assuming constant failure rate according to the bath tub model) then reversing back to a failure statistic.
"Shading issues would render a string based solution mostly useless" The whole "one panel shaded takes doen the string", thing has been disproven time-and-time again. Even at the worst shading levels, your bypass diodes will kick-in. "I have had zero failures, zero downtime in the 4 years since I had the system installed" I sincerely hope so, as the est. technical lifetime of those things is beyond 10 years, still much shorter than those of your solar panels (30+ years), which doesn't make it a good match... But you will figure that out with Gary once you hit the technical life of the micro-inverters.
@@GaryDoesSolar Its faux statistics by enphase anyway. As the failure rate BEFORE reaching est technical lifetime is not very relevant. Failurerates are always a 2 peak-curve, the first in the first 1 or 2 years of use, then a very low failure rate for a while and then a huge exponential growth in dying devices. So we can say with 100% certainty that those graphs are completely nonsense. (as the initial peak should be visible in the graph) But even more so, with the second peak missing, the only thing we can conclude is that almost no one is using them long-enough to give accurate numbers for the second peak.
Morning Garry. I have microinverters on my 12 panel system, had these fitted using Solar edge but I had forgot how they worked. I think you have reminded me what I purchased almost 5 years ago. Thanks for making it simple for me. Bob Blood Kent England.
I'm just about to get my own array in Canada and this was the most helpful video I've come across going over micro inverters and strong inverters. Thanks a ton Gary!
My daughter just installed solar on her house here in the Palm Springs area. I advised her to go with Enphase micro inverters, despite the higher up front cost. The installer gave her a deal on last year’s model of SunPower panels, which brought the cost down to the point where she could afford it.
Hi Richard, great news about the deal your daughter got - it sounds like it'll be a great installation as well - SunPower is premium number one in panels these days :-) All the best for her!
Just watched your last video and jive you credit I last sent a comment telling you my experience on micro inverters (e phase) My previous comment mentioned snow we are here in Canada! The systems we sold only used emphases ane the stats indicated a 15% on average showed the benefit We only hade 1 unit fail and it was so easy to diagnose Thanks for making it simple to understand Emphase😊 It’s the only way to go Chris
Excellent content. So good I’ve swapped to Octopus and used your referral code. You have taken a whole load of jigsaw pieces and made a clear picture. Thanks Gary.
The utilization of solar microinverters is currently the prevalent installation preference in the United States due to their numerous advantages. As a professional solar installer, my experience indicates that over 95 percent of my installations involve microinverters. These devices are particularly beneficial for shading, various tilts/angles, and advanced monitoring and rapid shutdown capabilities. It is important to note that, in the present moment, a central inverter installation is rarely the superior option. While the possibility exists for this to change in the future, the use of microinverters has become the de facto standard in the industry. It is important to mention that the preference for solar microinverters is mainly applicable to residential applications. In commercial or utility-scale installations, the use of central inverters is typically preferred, as they offer certain advantages such as higher efficiency, easier maintenance, and reduced installation costs. Therefore, the selection of the appropriate inverter technology must be made based on the specific requirements and circumstances of the installation.
Hello, Gary! Very informative, as always. Two points relevant to home solar, at least in Latvia: 1) Power balance between phases in 3F connections to the grid must be maintained, since most of the time home solar is feeding into the grid. It's very easy to construct a microinverter system with power imbalance between phases. E.g. last autumn I received a quote from well-wishing microinverter installers, who proposed my system as 4KW+4KW+2KW connection to the grid. They did not care about the feed-in balance. I did not go with them and installed a string Inv, that takes care of that balance. Now, from March 1 this yr, this is to be guaranteed before commissioning the system. Had I went with their offer, I'd have an energy inspector knocking on my door rather soon. 2) Energy storage in home systems are becoming a necessity. Microinverters do not live well with battery systems. Batteries are the rising trend on our shores, actually energy autonomy is (partial or full). Battery solutions with microinverters become more costly, than those with hybrid string Inv, not least because there are AC-charged batteries and simply more devices involved. I chose a string Inv over a hybrid Inv with batteries for cost reasons. Already now I consider it my huge mistake. I wonder what microinverter owners think about energy storage?
Thanks for the kind words, Andris - and thanks also for taking the time to comment with all this detail. You've given me some homework to do - balancing on 3-phases is not something I've considered before. Can you say a little more about your comment, "Microinverters do not live well with battery systems." please, as I'm thinking there should be no issues. Interested to learn...
@@GaryDoesSolar I have Enphase and a MultiPlus battery inverter controlling 3x Pylontech US2000C’s. No issues here. While it is true that the worst case for efficiency losses is converting DC/AC from panel to inverter, then AC/DC for charging the battery, then DC/AC for discharge, it’s worth considering that any spare energy would be going to the grid at a pittance anyway. Although you could charge your car on the AC output, it’s still going to get converted back by the onboard charger. You can’t win all the time I guess 😅
Interesting. Because the inverters do not set the power. The power is set by the load, that is what is consuming the electricity you feed into the grid, and that is something you do not control. The power rating of an inverter does not mean that is the actual power that is transmitted down the cables at any instant in time; the power rating of the inverter is the maximum power it can deliver. So, you could have 3 inverters rates at: 5kW, 5kW, 2kW. And if the grid is consuming 1000 watts on all 3 phases, (a perfectly balanced 3 phase system) then there is no problem as all 3 inverters are able to deliver enough current to feed each 1000 Watt load. The problem is going to come when the grid demands a power of 3000 watts on each phase - 2 of the inverters can deliver it and the third can't. But technically this is not balancing on 3 phase which is actually load balancing to keep the neutral current to a minimum, this is just ensuring the each inverter is the same maximum power rating.
A 2KW imbalance on a domestic property is nothing. If there are three properties on your street each on a different phase, and one turns on a 10.8KW electric shower...well, you see what I mean.
A plus to micro-inverters is that you do not need to deal with high dc voltages, expensive HV thick high voltages cables and DC circuit breakers. I have installed solar panels with micro-inverters in my house, in Brazil, since 2018 and it has been performing flawlessly since then, I am very happy with it since expanding is just a matter of adding more panel and inverters.
I always enjoy your videos, Gary. You strike the right balance between technical detail and effective communication to laymen like me. I wish I had access to your videos when I installed my system 4 1/2 years go. Fortunately, I had a good contractor who worked with me to design a system that has served me well - with the exception of the SolarEdge inverter that needed to be replaced after four months with two weeks downtime during the height of our intense desert summer. Recently, I observed my daughter and son-in-law going through the process of getting bids on a system for their house. I advised them to request Enphase micro-inverters despite the slightly higher cost. It
Thanks for the kind words, Richard. Sorry to hear about the troubles you had with your SolarEdge setup. And at the worst possible time too! I hope all goes well with your daughter and son-in-law’s own installation 👍🏻
@@GaryDoesSolar It turns out that my next door neighbor had a SolarEdge inverter fail in the first year of operation. It was promptly replaced and, like mine, has performed flawlessly since. However, this experience was a major reason why I recommended micro-inverters to my daughter and son-in-law.
I did a great amount of research before buying a micro-inverter system (USA). Still, you covered a lot of important points that I hadn't come across. Bravo!
Greetings from Australia. Thanks for the video, Gary. This is, without a doubt, the best video I have ever seen about solar installations. You have a new subscriber.
Greetings! 😀 And thanks for subscribing. I’ve never been to Australia, but do have an ever-increasing number of conference calls with companies out there. One day 🤔 😎
8:48 I'm very happy with my microinverters. 8 years without a failure of the microinverters themselves (enphase m250). Although I did get a squirrel build a nest and chew through one of the wires. As you mentioned at this point in the video, I have 36 panels and it only dropped my production by 1/36th. Hardly even noticeable. I just waited a month or so for nicer weather and repaired it then. Besides not losing power, the other nice thing was the wire to the panel that was chewed through and laying on the roof only was carrying 36V from the one panel rather than hundreds of volts with them all in series risking fire.
A BIG advantage of micro inverters if you don't want the DC for batteries is that you can slim down all your cables and/or reduce DC voltages as you say. I find multi hundred Amp DC positively scary and love micro inverters, but I can get at my panels so I don't need to care if the inverters fail more often - and 10 times as many inverters will create 10 times as many equipment failures on average.
Thank you very much again, and especially thank you for the hint towards the labor reimbursement program. This is good to know, even though it will not cover the whole costs if one of the inverters needs to be replaced. But who knows how often and if this will happen at all. Somehow it seems way less likely than with a central inverter.
Another very well made video Gary 👍 The biggest thing holding back microinverters is the lack of competition. The only game in town is Enphase so price competitiveness is currently very limited. It'll take another big company to develop their own mass consumer microinverter solution to change the narrative.
Thank you so much! They continue to be hard work to make, but feedback like this keeps me going :-) You're not wrong about the lack of competition in the microinverter space. I too, hope that will change before long. For example, why doesn't SolarEdge jump in?
@@GaryDoesSolar Western companies need good margins to justify R&D/product development. I think it's more likely that eventually a domestic Chinese company will be the ones to offer an Enphase alternative as they won't have US executive/sales/marketing salaries to support.
Hi, Yes. that could be an issue in the future. There were other manufacturers around but it seems like microinverters are not that interesting for the solar builders (as they can sell way less engineering). Still: It's a good sign the solution slowly but steadily gets more momentum. There will be other companies jumping on the boat sooner or later. Everyone I have been talking to really likes the microinverter solution once they did get what it's about. Tobias
Thanks Harold - that’s such great feedback to receive! You might also like to watch this interview I did a few weeks ago with Enphase: ruclips.net/video/kGCKarB7fnI/видео.htmlsi=dDbrA-U_nkKpI-hG
Hi Gary. I've got 18 panels (6.9kW) with Enphase micro inverters. I chose the system because I have a large oak tree (protected) that produces diffused shading in winter/spring once the leaves have gone (lots of shading in autumn!). I did watch your video on shading and bypass diodes but I'd already got the system by then and could see that they do actually produce a continuously variable output per panel across the array as the sun moves. I also like the idea of having 230VAC rather than huge DC voltages on the roof and, as you say, no voltage if you throw the isolator. The other advantage, that you hint to at the end, is that an AC coupled system is much more flexible when it comes to adding battery storage as well as allowing both solar and battery power to be used to supply peak demand (when the sun's shining) which could even power a 7kW EV charger. There is a limit to the number of panels that can be directly connected together (which I think is probably to keep it within 20A to protect the cable) but that is easily solved with a small CU in the loft.
Thanks for the detailed comment. Yeah, I would have spoken more about batteries on a microinverter-based setup, but the video was getting a bit long. My plan is to do a follow-up video shortly covering that and other feedback I've received through the comments. I'll remember to add in from the points you make here too - thanks! :-)
Fantastic article Gary. I am biased as I install Enphase microinverters. They are the most reliable system around and from a company that actually gives a damn about it's customers. Why bring high voltage DC into your home when there is absolutely no need. AC architecture is the only way to go.
Cheers Andrew - yeah, there are a lot of benefits! My main concern is the cost to replace a failed unit - especially on a two-storey property. Will the warranty cover the majority of this…?
@@GaryDoesSolar Hi Gary. I am obviously talking as an installer. As I type we have fitted just over 7000 micro inverters and we have had one fail. We have a duty of care to look after our clients and keep them happy and keep them referring business to us. Enphase replaced the microinverter by sending direct to the client. We then arrange to install at our earliest availability. This was within 2 weeks and bear in mind the remaining panels are all still working as there is no single point of failure. Now what does that cost me? Approximately £250. We have our own tower scaffolding that could be used on 90% of remedial work. Remember, we know exactly which micro has failed and therefore dont need full tube and clip scaffold to go "hunting" for the point of failure. If we needed full tube and clip then this would add about £350 to £550. So, who pays for that? Me and I can recover some costs from Enphase. So lets keep the number simple. Lets say the average install is 12 panels, we have therefore installed 583 systems. If the one failure cost me £800 to replace (it didnt) then that accounts for £1.37 per installation.(583 x 1.37 = £800). Its not worth worrying about. I very often say "I dont wake up in the morning wondering which Enphase installation has failed today". I cant say that for other systems. Now if we look at failure rate with some other manufacturers. One who shall remain nameless has in two years had approx 30% failure rate. They also have 100% failure rate due to recent server updates and customer complaints about none access to systems. This is inverter failure so no roofer required, just a sparky. Average cost to me £250. We only installed about 30 systems before I pulled the plug. We ripped the system apart and were appauled at the build quality. So, those failure rates have cost me approx £2250. Not good. The Supply of Goods and Services Act say that I am responsible and therefore the more of this cheap system I install, the quicker I risk going bust. Please also remeber that we are not just talking about Enphase micro's here. There is the Q-cable.This cable costs about 20 times that of 4mm DC. Why? Because it is built to last. Enphase is more expensive than a conventional string but you oly have to look at the quality of the materials to know why. I havent even touched on the battery system but can save that for another day. Recapp; no one calls me to say "My Enphase system isnt working". Regards, Andy PS Joti from Enphase has been trying to contact you to see if you would like to come out on an installation.
"String inverters typically last only 8-12 years" - where did this data come from? Enphase started producing 2008 -> I like micro inverters but its just too early to tell they last ±25 years. Imagine your micros start to fail after 25 years. Will you order somebody to change them one by one as they go off? Are you happy to buy new micros + installation as your old panels could still have +5 years 80% lifetime left? Very nice channel Garry and good information,thanks. Kudos from the early adopters part.
Hi Mikko, thanks for your kind words about my channel - it takes more hours than I would like, but feedback like this keeps me going! :-) In answer to the points you raised: Lots of sources on string inverter lifetime data, for example: www.pv-magazine.com/2022/10/03/how-long-do-residential-solar-inverters-last-2/ Before I got into a career in mobile, I developed software for semiconductor burn-in/test systems - essentially abusing computer processors and memory chips with thousands of hours of harsh environmental situations (heat, humidity, vibration etc.) until they die. From this data, you can make fairly accurate estimations on expected lifetime. You don't need to wait 25 years. In terms of practicalities, the world will have changed a lot in 25 years - I'm sure that by then, you'd simply replace your entire solar solution with a completely new one.
the failure rate are very skewed, they installed 3100 in five years, so that is not a rate of 3 failure per 3100 in five years. only one of the installs has been around for five years, and the very last install was only around for one day. since this is from startup i would guess about 2 percent in the first year and 30-40 percent in year 5 as interest grew. the failure rate math is therefore very very very difficult.
I have an older ground-mount string-inverter solar system, comprised of 24 x 280watt panels (online in 2013). I then had a second system installed with 23 x 335watt panels with micro-inverters on my barn roof in 2020. The 23 panel system consistently outperforms the ground-mount system, not just because the panels are of a higher wattage, but because the micro inverters can handle the shading of trees or low sun-angle shadows in the winter months much better than the string inverter can. It's really noticeable seeing the whole system have to go down to the lowest denominator, when the micro-inverter system still has maybe 75% of it's panels running at top effectiveness, as they're not shaded. I am still on the original string inverter, and it is now several years past it's warranty. When it does fail, I am really tempted to consider converting the ground-mount system to micro-inverters for the second half of their expected lifespan.
Since microinverters currently clip at 388W wouldn't you choose cheaper lower wattage panels to avoid this? Is there a reason for this 388W limit and will it change in the future? I appreciate based on your explanation that it doesn't make much difference to the overall output, but these seemed obvious questions that you didn't cover in your video. Great video, love your straightforward no nonsense factual style of presentation. Keep it up!
Hi Viv, the 388W limit will be different depending on the actual microinverter, and I'm seeing that with successive newer products, this limit is going up each time. Yeah, you could choose lower wattage panels (saving cost perhaps), to combat. Finally, thanks for your very kind words - I really appreciate getting feedback on my videos :-) I'll keep them coming...
Remember that a panel is only going to make peak wattage under ideal conditions. Only when the panel is pointed directly sunwards on a clear day. You're seldom going to actually see that much power.
Always very informative Gary! One thought about system design is that power electronics don't necessarily have to be mounted underneath the panels. They could be mounted in the loft. Lots of advantages: Easy to replace faulty modules without scaffold, easy to inspect connections, protection from damp environment. One disadvantage is summer time loft temperatures. I don't know how they compare to under panel temperatures, but I think I might do a temperature survey this coming spring time. There's typically about a metre of cable with each panel, which should be long enough to slide under the roofing felt overlap and connect to a power module mounted to the rafters. You touched on rapid shutdown in the event of fires. I read on the efixx youtube channel that there's about 10 rooftop solar fires a month in the uk. ruclips.net/video/DZeY6q5lscY/видео.html That will no doubt increase 10x as solar continues towards mainstream adoption. It might be worth exploring the causes of fires (if any cause can be determined after a fire), and how these causes can be designed out of the system. One thing I discovered during my fault finding process is that modern junction boxes for the bypass diodes are filled with a potting compound. This not only seals the connections from moisture, but it dissipates heat generated by the diodes a lot more effectively. I've always wandered how those diode legs in particular were rated to 15 amps of current, when the diode legs had a much smaller cross sectional area than the cables connecting the solar panels. Periodic inspection of the panel wiring is recommended under wiring regulations. However with MC4 connectors being under the panels, they are almost impossible to inspect without actually dismantling the system that you're supposed to test! That then loops back to my idea of having all connections in the loft space. Thanks for the shoutout by the way!
Thanks Anthony - hope you liked how I put your segment together :-) Aside from potential future roof leakage issues, the idea of having the microinverters within easy access makes a lot of sense (as easy as accessing them on a ground array!) Unfortunately, it wouldn't be an option for me though as our loft was converted into living space 10 years ago :-/ (You'll see my roof space in the next video hopefully) I did see some photos of the Enphase microinverter internals and they was filled with potting compound too - I guess that's how they manage to survive so long outside! The fire safety aspects could be a real problem for string inverters going forward. In most states of America, they just mandated MLPE and that was that. I can see the same thing happening here in the UK too.
Sorry @@allan4787 - I should avoid using acronyms. It stands for Module Level Power Electronics. Here's a link worth reading: cdn.ihsmarkit.com/www/pdf/0822/Module-Level-Power-Electronics.pdf
That'd exactly how I installed my EnPhase micro inverters. DC cables pass from each panel through in to attic space. Inverters are screwed to a mounting rail. That was for my first 10 panels, then I switched to using secondhand micro inverters for around half the price. I think there is a good potential market for reclaimed solar equipment....If the price is right.
I checked my loft temperature during June's heatwave. It was only 2 degrees warmer than the outside temperature. I must admit it felt much warmer but who am I to argue with what a thermometer says. Inverters are pretty reliable bits of kit. In the factory where I work, we have thousands. And they are running 24/7/365. Very rare for one to go wrong. And some of the machinery is well over 25 years old. Same electronics.
Hello, ive personally been in the PV world since 2014 and have done micro inverter systems on residential homes all the way up to 27MW utility scale projects and when it comes to the residential market the Enphase micro inverter is hands down the best there is out there. after installing thousands of micro inverters i have personally only had a handful fail. something else most people dont consider with PV setups and with micro inverters you can always put a module (panel) that's larger than the output of the microinverter. this will start you production earlier in the day and produces later in the day expanding your power production window. to sum it micro inverters are superior in so many ways (String/central inverters fail very often Solar edge 1-3 years 50% fail, SMA 5-7 years 50% fail) $$$ lots of money to repair/replace one con about the Enphase micro inverter is your a true survivalist these will not work for you since they require the 60hz sign wave (if your in the U.S) for the inverters to start outputting power. that means no off grid systems charging batteries and you cannot run off the receptacle that a lot of string inverters come with now a days when the power goes out. so if the grid is down so is your PV system no matter what (Unless you spend a lot of $$$ on a sign wave signal generator) im not an engineer or anything special just installed and repaired thousands of systems over the past 9 years and have formed my facts/opinions from that.
Thanks very much for taking the time to comment, and also for this great insight. Many people dismiss microinverters but they don't get the point that their failure rates are incredibly low, especially when looking at a timeframe of 25 years (like you would with other building attachments).
Thanks Gary, a very insightful video. I especially liked your analysis of the mass-market viability of micro-inverters. I never thought of that aspect myself. (And, sure, i fit your 'early adopter' profile exactly!! 🤓) One advantage of micro-inverters that you haven't mentioned is cable losses. To transport the generated power from the panels to the house/storage, there's going to be cables involved. With string-inverters, this will be DC power, and the current-per-string can be significant on sunny days. The panels i have can generate 9A peak. To avoid significant losses in the long-ish cables, you'd need at least 4mm-sq or rather 6mm-sq copper cables. That is a significant, and expensive, amount of copper. On the other hand, micro-inverters generate 230V AC (RMS) _before_ transport. Taking those Enphase IQ8 inverters as an example, at peak capacity of 388W, that would mean that _each panel + inverter_ injects 1.7A into the AC bus. That means that with 9 panels + micro-inverters, you're still under 16A RMS, and you can use very regular and affordable 2.5mm-sq cable for the AC bus. And if you have more than 9 panels, run as many parallel AC bus lines as you need. The cable is still much, much cheaper than the type you'd need when using string-inverters.
Thanks :-) I know there are many people out there who might instantly dismiss microinverters, but in line with the great points you raise, if microinverters were really not fit-for-purpose, then I'd like to understand from those people why Enphase, the leading manufacturer, is going from strength to strength?
This is all well but you are missing one crucial problem: to charge your home battery you want DC not AC. A hybrid inverter that feeds DC right into the battery and converts from both panels and battery to AC is much more efficient than a battery with separate AC inverter. On top of this a central inverter is much more efficient than microinverters are. Putting this all together the difference is huge! The solution to the problems you describe are optimizers which adjust the DC voltage of individual panels in a string. You don't even need them on every panel. So sorry to say that while in isolation what you say is right in conclusion it is wrong!
Hi Ludwig, thanks for taking the time to comment. With a microinverter system you can use any AC-coupled battery (e.g. Tesla Powerwall). True, there are additional conversion losses, but when I mapped out typical charging/discharging of both DC-coupled and AC-coupled batteries, there wasn't much real-world difference. What sources do you have to support that a central inverter is much more efficient than microinverters? I'd be interested to see those. I'll be making a video on optimisers soon - like other solutions, they have pros and cons, which I'll cover. However, I stand by everything I said about microinverters in my video. You don't need to be sorry about that.
@@GaryDoesSolar There is plenty out there on inversion losses. Microinverters will lose you 5% easily, and this is at their optimum power, so likely much more in reality. A great string inverter has less than half of these losses. Then there are cabling losses. Not only is the voltage often much lower than with DC strings, but the cables unlikely to be large enough to avoid significant cabling losses when high current is running. You need an awfully large cable to generate 10kW of power on a roof with microinverters! And then there is the AC->DC->DC->AC conversion loss for the battery storage which will be easily 5 to 10%. People also overestimate how much better optimizers and microinverters will fare with shading. They fare hardly better. The reason is that modern PV panels shut down part or all of the panel in case of partial shading. So the impact on the entire string is far less promounced than it was in old times. With very complicated roofs and patches of panels here and there microinverters may be the way to go, but otherwise they are unlikely to beat a more conventional setup, at least when that has been done well.
@@GaryDoesSolar Another issue that you are ignoring is multiple phases. In the developed world most residential houses run on 2 or 3 phases. With micro inverters you have to choose one phase, though you could potentially supply 2 or 3 phases in parallel by different micro inverters. However, they will not be able to balance the load between the phases, as a multi-phase strong inverter does. So you will find that sometimes you are buying power from the grid because one phase is short of power while in total you are actually selling power! This is not efficient, also considering that buy and sell prices are vastly different.
@@ManfredvonHolstein You haven't provided any sources to show string inverters are more efficient than microinverters. The battery topic is separate to that. With regard to shading aspects, I cover those extensively here: ruclips.net/video/9GvhDhCSJgo/видео.html
@@GaryDoesSolar Just look at the ratings of individual inverters and you will see. Also there is lots out there on cabling losses - in fact it is so basic you may just need to read up on the electric basics. You can also estimate cabling losses with online calculators - plenty of them out there. The overall point is that only because a microinverter may look nice in isolation it doesn't mean it will be the best solution in a system. It very often won't be, and that's also why they are not used much.
Seemed a good summary of the issues. Microinverters evidently the way to go. On roof connections more simple. Analysing performance and fault finding should be simpler. In general, many identical things are more easily dealt with than fewer customised things. I'm waiting for the solar panels to also provide the weathertightness of the building.
Yeah, at first sight, having complicated electronics on a roof exposed to all sorts of weather over 25 years sounds like a really bad idea, but I note that manufacturers like Enphase carry out a massive amount of climate testing, to make sure their products have the best chance of survival over that time
@@GaryDoesSolar I suspect that 230V connections are more reliable and more familiar to electricians. Make the LV DC as short as possible and as standardised as possible.
Micro inverters are a waste of money. Convert the panel to ac, then convert it to dc, then you put it in a battery. now you have to convert it back to ac to use it. I see a lot of losses here.!!🤔
An MPPT charger does a similar conversion: convert to AC, match battery voltageand current, convert to DC. It is true that an MPPT charger does use a higher internal frequency and so can do the same job with much smaller components. Also, the whole thing is built as a unit and so inverter and charger are matched. What might be interesting is micro inverters that run at a higher frequency than 60Hz with purpose made chargers on the battery end. The transport voltage could 240V while still using standard, well known, cheap, House components such as breakers and wire. There would be less loss in the panel to charger wiring (this may be true even with a 60Hz micro inverter).
My system designer is specifying Enphase IQ8A inverters to mate to my 31 Q Cell panels (12 east and 19 west) aside from all the points you mentioned I was informed the micro-inverters can start up with much earlier than string inverters. I might get an extra hour each day of collection at the beginning and end of the day. We did discuss Enphase's SunLight Only option, but since we plan on adding batteries in the next 12 months (hopefully a tesla Powerwall 3) I opted out of that functionality.
Sounds great, Thomas. Good luck with whatever you decide and I'd be very happy to hear how you get on :-) Yeah, let's hope the PW3 appears on the horizon soon!
Yeah, these kinds of systems are not for everyone, but I do believe it allows the supplier to quickly diagnose any problems in-life. Most new cars in the last few years already have such monitoring.
@@shaunclarke94 who knows what could happen. Things could stop working after an update and you're asked to pay for a further update. Or maybe a new TAX on energy you generate.
I won't upgrade my Litterbox for that reason. It HAS bluetooth to talk to my phone, but it doesn't use it except to talk to Litter Robot to assign an IP so the box can tell them when my cat takes a dump and then they can tell me. If i'm not home, knowing the box is full does me no good. The bluetooth is more than enough range to ping my phone without notifying the NSA.
Thank you for the detailed explanation on microinverters. Based on what you laid out it is clear to see where the advantages are and I learned a lot in the process.
As panels degrade you can add an extra panel ezi pezi, and maintain the full production. Or as you get a second EV add extra panels. Great work 👏 👍 👌. 'Low' voltage on a metal roof with a roof verandah is a great feature.
Hi Gary awesome videos, great stuff, I think your mostly right, but for me the cost of buying enphase micro inverters cost more than buying multiple string inverters
Hi Tim, yeah - you're right. The costs need to come down so they're more comparable with other solutions. Hopefully, that will happen over time, but some decent competition to Enphase would certainly help!
Great video very informative. One thing to take into consideration when it comes to cost. You still need another inverter for the battery. This means still a inverter that needs changing. Most solar system are fitted with one hybrid inverter for solar and battery
Good point - I'm thinking of doing a follow up video in a few weeks, in order to include all the feedback and insight I'm receiving, including from yourself - so thank you for that! :-)
Great video Gary, thank you for putting it together. You have convinced me that micro-inverters are the way to go. I like the approach of each panel is its own individual element and the management at that individual level is key. Cheers
Well done Gary... watched the lot. We have extension plans for our house going through at the minute and solar + battery will be installed. However, I though I had a solution figured out but after watching this I'm not sure...
Hi Phil - thank you for taking the time to watch all my videos. I hope you managed to get a lot of value out of them. And apologies, I've given you more to think about!! Hope you settle on a great solution :-)
Enphase system owner here. It’s a great system and I really love it. Would be great if Enphase were more competitive on their pricing structure. The cost premium for an Enphase system over a traditional string inverter setup is rather high. For example, here in Australia a string inverter 6.6kw system would be around $6k-$7k with good components and reliable panels. The same thing but with an Enphase IQ7A system will cost around $11k. That’s a fair whack for the benefits that come with the Enphase system. I have a lot of elderly people as neighbours, retired etc… I couldn’t recommend the Enphase system to them unless they either had dynamic shading issues, and/or had the money to make such a decision.
Thanks for the feedback 😀 It doesn’t correlate with countless other comments I get saying the opposite, but I’m also happy to help those with insomnia 👍🏻
I'm a great fan of panels on a ground mount if back garden faces south and you have a big garden. Mine are tiltable and easy to measure individual panels if suspect a fault.
As always Gary a great explanation and explained exactly why we went with microinverters, having 3 panels on the house (due to shading restrictions) and 10 panels on the garage 30m away. Splitting the installation across two buildings gave us much more flexibility. Another benefit is the Enphase Envoy is tiny compared to an inverter. I've only had the system for a few weeks but been very impressed so far.
@@GaryDoesSolar If your installation is not installed yet, it may be an idea to see if your suppliers/installers can go with microinverters for you. They may put your actual installation back but you say that now you "would certainly go for microinverters". It's worth seeing it they can accommodate your new requirement as requirements change up to, during installation and post install as more practical knowledge comes to light.
@@dapperdynamicdavid I did consider doing that, but in the end I decided against. I actually want to get deep experience of the GivEnergy products I've ordered) as they seem to be geared for dynamic energy tariffs - a topic for a future video I want to do.
Brilliant channel and in depth analysis Gary. I'm finding it difficult to decide between Micro and string inverters and just when I was convinced another question popped up. Conversion loss... Microinverters will suffer a fair loss when coupled with battery backup? Panels to Microinverter DC - AC loss, AC - DC loss when charging up the batteries. DC -AC loss when using battery storage? With a hybrid string inverter you'll only suffer the conversion loss once? More food for though?
Thanks for this great feedback, Jack :-) Now, you're totally correct about the difference in conversion losses between AC and DC Coupled batteries - but when I model different scenarios with my utilities, in practice I've found it doesn't make too much difference in the results, so I (personally) wouldn't make a buying decision for AC or DC Coupled based on that fact. See my video here, where I talk about DC and AC Coupled battery operation and losses here: ruclips.net/video/x83t1iCMXxw/видео.htmlsi=ftHdXYE5e5oD0BAR
Really interesting video. I think we need to bear in mind that Australian weather is not the same as the UK, so we can be confident that the products cope well with heat, but I’m not sure we can say the same for cold and damp winters. They may be brilliant in our climate, but we cannot assume that from the Australian data
Thanks Billy. Yes, good point. So my thinking is this: It's true that the two data sets I cited are both Australia, but the Enphase quoted failure rate (0.05% over 25 years) will be a global rate. I'll see if I can get a breakdown of that rate. Enphase do a lot of climatic/burn-in testing of their products - here's an example video (check the section at 2m4s): ruclips.net/video/mq3NyIizlu4/видео.html - early in my career, I wrote a lot of software for these types of test systems, so I know how effective they are at weeding out any long-term failure scenarios (like cold and humidity, as well as heat).
We currently sell wifi controlled micro inverters for 'balcony' installed systems for condos and apartments. Its an affordable option for those living in smaller abodes. The installation is so simple that anyone can do it.
@@GaryDoesSolar I believe the adoption of micro inverters for a mass roll out situation is likely as long as there is good govt policy and support for it. Things have to change drastically in the UK for that to happen!
Thank you for yet another excellent video!! One nit that’s been bugging me is this is the second time I see you plot 100% power output on a chart. In this case 415 watt output from a 415 wp panel. Does anyone actually see that in real life? Maybe I have grown too pessimistic… It makes the clipping even less of an argument.
HI Peter, so, my panels are 415 watts each and even now (in November) if it’s bright sun midday, they produce that amount of power 👍🏻 My array is South-facing near Oxford in the UK.
Hi Gary, really helpful, thank you. Really like to know more about the micro inverters on the market. APsystems look particularly interesting, with some models having lower startup voltages and higher clipping levels.
For some reason I have not had very good luck with microinverters. Over 4 years I have had to replace 6 out of 31 microinverters. And it has been a pain in the neck to replace after each failure because the failure has always ocurred during very hot weather. If I had to do it again I would definitely go with a couple of string inverters; particularly with new panels that are equipped with diodes that solve the series problem.
Thanks for sharing this Dave - and sorry about the problems you’ve been having with microinverters. Do you know if it’s actually unit failures? I ask; because sometimes it’s due to the wiring and connectors not being fitted properly.
There are so many permutations that it's tricky to make decisions. I have quotes for a 16.7KW multi array system with battery on grid. I live near Sydney Aus. I have 3 phase power. One quote is for 2 Sungrow multipoint string inverters and 2 optimizers to 2 slightly shaded panels. The second quote is for 38 Enphase microinverters. On trying to analyse and compare, I found myself in the weeds, confused, dazed, divided and conquered. Although videos like these aim to help, they really don't because they raise more questions than they answer. It is after all electrical and electronic engineering. So anectdotal evidence from installers aside, be they well meaning. I am choosing the string inverters. Why? Price.....with the difference I can buy 2 new inverters when they fail. Building is 2 storey........and Nothing lasts forever and 25 year periods are purely academic and meaingless in real worlds....and lastly....just a gut feeling that when the discussion gets complex and polarized, my solution, whatever it is, is the right one and the best. Cheers and thanks for the vid.
maybe nice for shading issues and simplest setup for installers. outside that, plenty drawbacks. Enphase inverters are power limited to the latest large panels. Cost of a single micro inverter with limited output is 1/5-1/4 the price of string inverter with 10x power. I also haven't heard seen a micro inverter for backup power mode.
I don't think microinverters add much value wrt shading, except in particular circumstances (outlined in the video). Costs of microinverters today are certainly an issue, but hopefully they'll come down over time. Regarding backup power, I believe the TeslaPowerwall can provide this - it is an AC-coupled battery, allowing it to be combined with a microinverter solution.
@@GaryDoesSolar you have a point with the Tesla Powerwall but then it is an excellent system which is even more expensive and now it is only available to buy with a Tesla Solar system purchase. I like the simplicity and robustness of microinverters, I guess it becomes superior to places with high reliability grids, like less than one hour power failure every ten years and good net metering.
Thank you for good infomation. One question that still prevent me from using micro inverters is: how do you prevent electricity generated by solar panels from flowing back into the utility line?
You're very welcome :-) The controller unit for a microinverter solution (for example, the Envoy unit with Enphase) should take care of that for you, by instructing the microinverters to curtail their production.
Glad you are so excited about Enphase Microinverters. Too bad you didn't mention that the advantages only outweigh the disadvantages until you want to integrate storage. Since only the integration of AC storage is possible, the costs are far higher than when using a Solis hybrid inverter S6-EH3P(5-10)K-H-PRO, for example, which 4 strings and a cost-effective DC storage can also be connected. In addition, there are the significantly higher conversion losses with AC storage.
Helmet, your argument would mean *nobody* would buy AC-coupled storage irrespective of whether microinverters were used or not. And as the market clearly shows, that’s not the case.
You need to lend your voice to a nature documentary series, ahhh yes, got the factory integrated Sunpower panels with IQ8’s booked in to be installed in a few weeks💪💪
Sounds like a wonderful idea until a fault occurs then the trouble starts. First get your sparky to find why the rcd keeps tripping. Next scaffold the house to find the faulty micro inverter which can be very time consuming and inaccessible. Replace the faulty micro inverter and send the customer an invoice for two days work plus the scaffold. Stick to the standard string inverter and save yourself a lot of hassle and expense. My string system has been installed for 11 years with no trouble and always generating ! Plus the Kako (german) inverter is cheap to replace.
Hi Peter, thanks for taking the time to comment. Yeah - until someone figures out cost-effective, safe roof access, it's a real negative point for optimisers.
HI Gary, love your videos, probably the best source of balanced information I have found. One question I have for microinverters, is their start up in lower light levels, as I will have some NE facing panels (in the UK). A salesman suggested microinverters have improved lower startup levels.. but I am struggling to see comparative data with string solutions to validate that claim. Have you looked into this?
Cheers for your kind words. It's not something I've looked into, so I don't have any data. I hope to be speaking with Enphase soon, so I'll ask them...
Thanks. And any AC Coupled battery can be used with a microinverter installation without problem - and it will perform just as well as it would in a string inverter system.
First off: i have both a string inverter and a group of enphase. Both have strengths and weaknesses. Every time there is a negative aspect to mention about microconverters like enphase (i have such a system) you leave it out: 1) the 230vac production means you have to string anyway if you are talking about 8kw+, 40-50amps requires expensive thick wiring, so string wins here as typical target voltage range 600-800V. Higher voltages equals less loss, cheaper wiring. 2) brings up second point and that is startup point. My enphase array starts later producing because i can’t stack voltage by putting more panels in series. So the sensitivity of microconverter looses from single converter. 3) my enphase micro top off in mid summer, loosing out on potential production, 4) the largere the array of pannels the bigger the price difference. String inverters are cheaper per kW production, alot cheaper. Why still choose Micro? Shading+irragular spots for small groups of panels, then go micro. If you make a 16+ panel array on a barn, always go for string inverters… this i advice from my own experience having both type of systems. Last thing: microsysteem is not cleaner, you still need to place an additional Envoy unit (which also costs 300€+)
I have had enphase microinverters for almost a year (IQ8+). No real problems but one thing I have noticed is that the more microinverters you have the slower the response time to load changes. When I only had 10 it was really fast, now with 24 it is noticeably slow.
That is strange. Are you sure it is the micro inverters, and not the grid tie box? Seems to me the inverters should always be pumping out the juice from panels, it is where it goes after that..... Sounds like the power company want your power more than you do.
@@robertsmith2956 Probably a combination, it was covered in EEVLOG. Its part of the control algorithm. The more you have the more it has to compensate.
Another fantastic video. My system is beginning to give me some good numbers. The panels on the back which are west north and beginning to get more sun. I will be launch my blog soon covering my generation numbers and mentioning this channel as a great resource. Gary, would you mind if I drop the link in a comment? I want to share my stats as I see videos on RUclips with other people showing there stats, but of course everyone is different and panels facing different directions. One last thing, and this is a bit tongue in cheek. When you logo zooms out the start, I always think it is a nod to the Scottish flag.
Excellent video. The absence of a central inverter means less space needed. The envoy is small and can go anywhere. However, we all assume internet is available or a customer is ok with having his system visible to the outside world. What happens if you only want accessibility locally?
Many thanks as always for your kind comments! :-) I'm not sure, but the Envoy might only be mandatory for initial configuration of the microinverters. After that, you could simply disconnect it from the Internet? Maybe others have a view on this...
Probably too late to the party on this one but figure there are many guys like me who are looking at this issue as we make our solar system choices. In my case I went with a single large inverter (Sol Ark 15k with 200 amp bypass capability). I am not going to use net metering and won't be selling any power back. I am using batteries (my other discussion with you) to capture my excess power....but only to the point where the battery payback makes sense....because I can pull from the grid. The whole payback issue has to be matched up vs the cost to just take it from the grid at 15 cents a kWh. Yes, it makes sense to factor in long term inflation when looking at the grid power costs...but...here in Texas that is a real challenge. Rates have ....at times....been very stable for years...only to have jumps. So...I did most of my math keeping the current grid rate of 15 cents....inflation...for me...will be gravy and make my payback faster. So in my case...I decided that I was more confident in the single (expensive) and highly efficient Sol Ark 15k managing 27 panels...plus...I will have a lot of excess power that will flow dc to dc into my batteries...vs the micro inverter choice. I spent my whole career in the tech industry....including computer data centers. My issue (which I can't prove) is that I look at both the micro inverter and optimizers as points of failure. Then...if it is roof mounted or a challenge to get to...I see that as further risk factor. I don't personally believe the failure rates will remain low over longer periods of time in harsh (hot) conditions but IF they do work then my risk issue is unfounded. At the same time, I see many of the benefits you state about micro inverters ...for me it would be the very simple concept that each panel is a little AC power plant that is easy to watch and manage. I'm not sure I buy into much of the debate about micro inverters and optimizers making the shading / power optimization thing worth the extra cost...because I think the panels these days go a long ways to doing a lot of that. Your other videos were great looking at the real impact. Finally...and this is a hard thing for folks to consider...is...that as panels continue to drop in price....in my case I was able to get the panels for 33 cents a watt...545 watt bi facial ones...I think more and more...if you have the space....the answer will be...just add more panels? In any case your video really made me think a lot about my setup and if I should consider changing my approach. I'm not really "religious" on any of this stuff....and....I find that a lot of the time there is not a clear...absolute answer....in part because of lack of data...lack of time for products to be in the real world....and finally....will your warranty even matter and will your suppliers even be in business when it comes time to try and get warranty or out of warranty service? I've almost discounted all the warranty stuff under the belief that most of the folks I buy from today won't be around in 5 or 10 years. Someone will be around...but...much like I treat my pool....or my HVAC systems....I will call someone reputable at that point in time to service my solar system. Now...that is probably why the big companies can make a consumer feel good....i.e....one would assume Tesla or Enphase will be around to take care of you...and...this may justify spending twice or three times as much for your system. Each person has to place a value on risk when they venture into solar and batteries today!
Thanks Scott, for taking the time to write this excellent analysis! :-) I might be speaking with Enphase shortly, and will ask them about their view on reliability...
I have enphase inverters. Have 17 and 7 of them needed to be replaced over 6 years. Also, the brain has been replaced 4 time. System currently not working and enphase admits they are stumped on how to fix. I’d recommend getting one large traditional inverter.
Sorry to hear you’ve had such a bad experience with microinverters. If Enphase is stumped then that’s saying something! Do you think there is something about your particular installation that is causing all these failures? Has Enphase indicated to you what the causes of the failures, if they have the returned units and associated data?
@@GaryDoesSolar they have changed the inverter generations over the years as well as several upgraded router hw over the years. Additionally, they have updated the FW on the router. This latest FW update doesn’t play well with older generation HW. I have a mix of several micro inverter hw generations since they have been replaced as old ones die. This combo of multiple HW is a nightmare for them. Even if you install new systems today, over time you will replace bad ones and they will keep updating new ones. Long time maintainability is an issue with them I think. I’m told i may need to replace all old micro inverters with new ones even though they work. I may be out of pocket a lot. If I had gone traditional I’d have been bette off.
Thanks for the extra detail - this is good information for anyone looking at microinverters. Ideally, you don't want any failures of course, but if you do, depending on how many you have, you could end up in a scenario similar to yourself. I've been in the mobile industry for a long time, and forwards and backwards compatibility are key to building a workable ecosystem. It sounds like Enphase are struggling with this potentially.
All excellent points in favor of using micro-inverters for a grid tied installation. Not so much for use off grid since micros need a "startup signal" to begin converting the output of your solar panel to AC. All of the string type inverters for sale in the US that are UL certified (I don't recall the number) have rapid shutdown capability built in. Thank you for sharing your research!
They will work fine with AC coupled batteries. I have Enphase micros and a Tesla battery and they will happily start and run on the AC signal provided by the battery.
Gary, being totally off grid and dependent on battery power when the sun goes down. How would the batteries now be charged with the panels used this way and how would the batteries be brought into play
So, you can add an AC Coupled battery to any microinverter installation. But in an off-grid scenario, after the sun goes down, your supply will be purely from the batteries - and when they're empty, you lose power. The only option then is to have a fossil-fuel generator on standby, maybe...
My pleasure, and sorry for the audio issues - I was using a new microphone but I didn't manage the audio settings properly during editing. Was all sorted with videos coming after that...
Hi, Interesting video. However you seen to completely changed your view. In previous videos your conclusion was sting arrays kept complicated equipment off roof, and doubtful if additional cost of microinverters were worth it in most circumstances. Please clarify your change of heart. Thanks
Hi Laurence, thanks for watching the video, Yeah, you're right - I have warmed up to microinverters, but that's only because I'm spending countless hours researching them, and as I take on board new information, it will surely affect my views on topics (as it should). What impresses me about Enphase is that they've set out to create products that will operate flawlessly for 25 (and soon 50) years - and they're investing heavily in solid warranties behind them. I'm not seeing the same from the string inverter manufacturers, who can't seem to get past 10 years...
Those who can have ground mount arrays with plenty of room can just add more panels. If I was so crowded that I had to put panels on the roof,I would move. I prefer off-grid so I can fail or survive on my own since I live in Texas. The wood peckers have to keep one eye open in case the rotten poles fall down.
@GaryDoesSolar The only thing i see is there technology were over passed by the newer solar panels > 250W (10 year ago) vs 400W and more today. The SB240 go only at 240W max. I have a installation with 8 of those ☺
* NOTES SINCE PUBLICATION *
Some people have asked if this video was sponsored by Enphase. I can confirm it was not, and that I received no monetary or other benefit from Enphase for making it.
Hi Gary, I just read through the comments below this video and I'm sorry that you're receiving so many hateful comments, while all you're doing is trying to educate us on solar. Hopefully these comments don't discourage you to create more videos, as there are also many people (like myself) who learn a lot from them. Keep up the good work :)
Hi Renske, thanks - yeah, I guess this is the world we live in now. It doesn't matter how well-researched the content is, there will always be those who have something negative to say about it (always far easier to critique than create). I don't worry too much about it - and RUclips gives me enough control over any comments that cross the line...
Judging from the overwhelmingly positive feedback I get, I think my content is very welcome, so don't worry - I'll keep the videos coming :-) I really appreciate you taking the time to raise this!
Haters are just fools disguised as idiots.
Hi Gary, After several years of pondering and researching, and many RUclips videos including your excellent productions, I have finally taken the leap and placed my order for a 7KWp solar PV with Enphase Microinverters and Givenergy 13.5KW AIO battery and gateway. I really like the flexibility and redundancy that Microinverters provide, along with better warranty and detailed panel-level power generation telemetry data - all discussed in your excellent video here. Thanks for all your great work!
That’s brilliant, Mark. Thanks for your very kind words and I hope all goes well with your setup - it looks a good one! 👍🏻🤣
Apart from remote monitoring and optimization, what differences are there between micro inverters & parallel pv string connection paired with hybrid Mppt inverter, especially for an array below 5kw.
Feel free to come on and tell us in 20 years, (way past the targeted technical lifecycle of an inverter) how 1 dies every year, requiring expensive work on the roof.
Warranty is all fine and dandy, but max technical life of a panel is wayyyy byond 30 years, thats multiple times the max technical life of the inverters.
Roof work is expensive, you will come to realise that in 15-25 years.
@@gozieanyiam7169 The fact you will require roof work for every one of these things breaking down. Every-single-time.
The lies in metrics Gary is showing here, are not relevant.
Obviously they dont fail in 7 years. But their lifespan is FAR FAR shorter than the 30, 40 or even 50 years your panels can just lay-there without replacement.
@@kjeldschouten-lebbing6260 believe it, parallel pv string connection with the necessary protection systems beats micro inverters (price-wise & in reliability)
After about 2 years of searching for a solution to my mottled winter shading problem (and humid environment) I can finally make a decision.
Thank you so much Gary.
Hi Rory, good luck with whatever you decide :-)
MicroInverter Ecosystem Questions:
I have been wanting to understand
Understanding Micro Inverter Ecosystems
for a long time.
Unfortunately no one explains in detail this type of inverter ecosystem.
Your explanation is great, but:
Here are my QUESTIONS, for your future videos, or to answer in a reply:
1) when you daisy chain multiple micro inverters onto the backbone wire, how do they stay in phase with one another?
2) when you have multiple runs (backbone runs) how does each run stay in phase with the other runs?
3) how do you wire multiple runs into an AC breaker box, to then be distributed for use to the house or building?
4) How do you store energy from these micro inverters which output 240V AC into a DC battery bank?
5) how do you get energy out of the battery bank and into the AC Breaker Panel, and keep it in phase with the input from the micro inverter runs?
6) How do you get Split Phase out of each run and maintain sync across multiple runs, and how to wire split phase into the breaker panel from multiple runs?
I have more questions, but if you could answer those in depth, it would be greatly appreciated.
Thank you.
Hi J K, thanks for taking the time to comment, and also your questions. I just don't have the time to answer them all (or the next batch of questions you have coming), I'm afraid. Perhaps others can...
One thing you didn't mention is the possibility of fitting the microinverters INSIDE the loft space. This is what my installer recommended in 2017, and they did a very neat job of it. I had an inverter failure recently (Enphase), but I was sent a replacement quickly free of charge and an electrician friend just swapped it over for me in a couple of minutes using no more than a screwdriver. There is an added benefit in that you can swap two inverters over to work out whether a particular inverter has failed or the panel attached to it has failed. The Enphase microinverters flash when they're generating AC, so you can spot a failure easily, without having to check through all the serial numbers. Thanks for your channel - it's really well done and very informative.
I didn’t mention in the video, but it did come up in the comments after release. Assuming no leakage issues, it doesn’t sound a great way to manage the risk of any failure 👍🏻
I am embarrassed to say that I had accepted the myth that only those that qualified for the old feed in tariff saw the return on investment! I wish that the people running the country adopted the same level headed no nonsense approach. You have my vote Gary and hats off to you.
Hi Barnaby, you're too kind, but thank you. I agree though, that this country (and many other countries) are run by people who don't necessary have a good grasp of the issues at hand, or how to effectively deal with them.
@@GaryDoesSolar One of the issues that leaders have only JUST cottoned on to, is that ROI is only a small part of it
If every single house had solar panels, including those that face north, we'd have a lot more solar output going back into the grid, whilst making things cheaper for people as a whole
The few billion in debt in the short term pales into comparison to the returns.
The biggest returns for a country are :
Energy security
Grid resilience
I've only really realised after I got solar panels, that my solar panels are essentially an extension of the grid because it still has to talk back to the grid. For this reason, if the grid isn't working, the solar panels also don't work. Batteries however would work
Being decentralised helps in terms of say anyone wanting to bomb energy infrastructure.
We'd still maintain some form of centralisation via the national grid ofc
I've had an Enphase system with Micro Inverters and a Tesla Powerwall for the past 3 years and would never go with a central inverter due to a single point of failure you pointed out. I'm in Las Vegas NV and have produced 38.5 MWH over the past 3 years, when I return to the UK and put solar in, I will certainly be using Enphase Micro Inverters again.
A friend of ours had a single inverter and did not realize for 2 months it had died and their system did not generate power for that period!
Thanks for sharing your microinverter experience here. Wow - that's a LOT of generation, but perhaps in LV, that's to be expected :-) Will you get a chance to go to a show in The Sphere before you return to UK? Something I'd love to do!
How much more did you end up paying for Enphase over a central inverter. 2 times, 3 times, 4 times, 5 times????
I have 23 IQ8+/IQ8A micro inverters and that is the way to go. So simple to add more. All plug and play. You can even commission them yourself if your a DIY guy. My neighbor is an electrician and I just mount them all up and he makes the final connection which is as simple as adding a breaker to the combiner box and connecting two wires. Even a caveman can do it. I think the hardest part of adding more panels was running the conduit/pvc and pulling the wire. Time consuming but not hard. I love micro inverters. Nice video!
Cheers - you might also like this interview I did with Enphase too: ruclips.net/video/kGCKarB7fnI/видео.htmlsi=RiYZ0NwX3P1JhOGt
There's a lot to be said about Microinverters :-)
Got a 5kw system installed about 10 yrs ago with micro inverters, never had any trouble with the system unlike our previous house where the big inverter died after 5 years.
Hi Steve, thanks for taking the time to comment. I think there is huge fear of microinverters failing all the time, when the reality (and the stats) show otherwise.
I have two sunnyboy inverters 14 years old but i wouldnt let them fit them in the loft to keep them out of high temps
@@GaryDoesSolar In reality, almost no one actually has them close to their est. technical lifetime.
So you cannot say that at all. Thats not valid statistical work at all.
Nice and all, but if the technical life is 15 years and after that time one dies every year, the costs are not funny at all.
Whereas a dead string inverter is a 2 hour switch-job at best.
As someone with a real-world micro-inverter solution, everything that Gary has said makes utter sense. I have 31 panels with 10Kw potential generation spread across East, North and West elevations (Australia). Shading issues would render a string based solution mostly useless, instead I have reliable, predictable generation. I have had zero failures, zero downtime in the 4 years since I had the system installed. I use a Blue Catch intelligent diverter to power hot water from solar. I will be adding some more capacity and a Tesla Powerwall to the system shortly. It will give me backup protection and combined with Tesla's VPP, I can expect minimal bills. I prefer the initial cost disadvantage in the knowledge that reliability, longevity and TCO will make micro-inverters the better choice.
Thanks for sharing this Nick. All too often, all people see are complaints when solutions are not working, and this leads to a strong bias against (a bit like looking at hotel reviews, where a 99% positive rating across 5,000 reviews might be discounted heavily because of 2 or 3 bad reviews). It's great to see that your micoinverter solution is working well :-)
@@GaryDoesSolar , I have a question about the failure rate calculation in the video. You show up in the first sample 3100 MC installations in 5 years by 3 failed modules.
Would be a rate of 3/3100*100=0.0968% and in 25 years 5 times this=0.484% assuming a linear propagation of the faliled modules while the reality would be more steeper increase.
Can you clarify how you got to the failure rate of 0.064% in 25 years?
The concept of enphase is nice but has also disadvantages. They are expensive. Some Inverters have also waranty up to 25 years and even if they have only 10 years, in general they last 15 oder even 20 years, before they need to be replaces, which is much easier end less expensive than replacing the MC on the roof.
The string size with enpahse is limited to 16 or 19 modules. You need the controller and additional rellais, which all needs housing and wiring. And also bad is, that the akkus are very expensive and you are bound to enphase.
In practice, because of the bypass diods and the shadow management, you have not that advantage they claim.
@@loukili63 It's been a while since I made this video, and so I'd need to dig out my notes for the calculation methods, but for the 3,100 sample, the important thing to remember is that number of units grows from zero to 3,100 over that time, so I likely used the midway point as an average (i.e. 3 units failed out of a notional 1,550 units operating for the 5 years). Then I would have calculated the probability of survival over the same 5 years, before extrapolating that out to 25 years (assuming constant failure rate according to the bath tub model) then reversing back to a failure statistic.
"Shading issues would render a string based solution mostly useless"
The whole "one panel shaded takes doen the string", thing has been disproven time-and-time again. Even at the worst shading levels, your bypass diodes will kick-in.
"I have had zero failures, zero downtime in the 4 years since I had the system installed"
I sincerely hope so, as the est. technical lifetime of those things is beyond 10 years, still much shorter than those of your solar panels (30+ years), which doesn't make it a good match... But you will figure that out with Gary once you hit the technical life of the micro-inverters.
@@GaryDoesSolar Its faux statistics by enphase anyway.
As the failure rate BEFORE reaching est technical lifetime is not very relevant.
Failurerates are always a 2 peak-curve, the first in the first 1 or 2 years of use, then a very low failure rate for a while and then a huge exponential growth in dying devices.
So we can say with 100% certainty that those graphs are completely nonsense. (as the initial peak should be visible in the graph)
But even more so, with the second peak missing, the only thing we can conclude is that almost no one is using them long-enough to give accurate numbers for the second peak.
Shout-out for the effort and polish that went into the graphics and animation in this video. Great job!
Thanks Geoff - yeah, a LOT of hours (they're just PowerPoint animations) but the results are not too bad.
@@GaryDoesSolar wow, they look a LOT better than what I would assume a "PowerPoint animation" could produce. They really bring the narrative to life.
Morning Garry. I have microinverters on my 12 panel system, had these fitted using Solar edge but I had forgot how they worked. I think you have reminded me what I purchased almost 5 years ago. Thanks for making it simple for me. Bob Blood Kent England.
You're most welcome, Bob - and great to hear your solution has been working so well :-)
This is a great site to bounce ideas off of. It is great to talk informatively to the solar companies. Thank you!
Thanks for the great feedback - really great to hear! :-)
I'm just about to get my own array in Canada and this was the most helpful video I've come across going over micro inverters and strong inverters. Thanks a ton Gary!
You’re most welcome, Adam - and good luck with whatever system you choose! 😀💪
Excellent content. Makes me proud to be in solar sales woth a company that provides microinverters.
Thank you. You might also like this video where Enphase let me interview them: ruclips.net/video/kGCKarB7fnI/видео.htmlsi=2qYRZ-BYHfiUv0pL
My daughter just installed solar on her house here in the Palm Springs area. I advised her to go with Enphase micro inverters, despite the higher up front cost. The installer gave her a deal on last year’s model of SunPower panels, which brought the cost down to the point where she could afford it.
Hi Richard, great news about the deal your daughter got - it sounds like it'll be a great installation as well - SunPower is premium number one in panels these days :-) All the best for her!
Just watched your last video and jive you credit
I last sent a comment telling you my experience on micro inverters (e phase)
My previous comment mentioned snow we are here in Canada!
The systems we sold only used emphases ane the stats indicated a 15% on average showed the benefit
We only hade 1 unit fail and it was so easy to diagnose
Thanks for making it simple to understand
Emphase😊
It’s the only way to go
Chris
My pleasure, Chris - and great to hear your positive experience with Enphase microinverters :-)
Excellent content. So good I’ve swapped to Octopus and used your referral code. You have taken a whole load of jigsaw pieces and made a clear picture. Thanks Gary.
Hi Derek, that's very kind of you - thank you! And I'm so happy to have been able to help you out a little :-)
Hi Gary, thanks a lot for the great summary on Microinverters. Keep up the good work and let the haters be haters 🙂 BR from Germany, Max
Cheers Max :-)
The utilization of solar microinverters is currently the prevalent installation preference in the United States due to their numerous advantages. As a professional solar installer, my experience indicates that over 95 percent of my installations involve microinverters. These devices are particularly beneficial for shading, various tilts/angles, and advanced monitoring and rapid shutdown capabilities. It is important to note that, in the present moment, a central inverter installation is rarely the superior option. While the possibility exists for this to change in the future, the use of microinverters has become the de facto standard in the industry.
It is important to mention that the preference for solar microinverters is mainly applicable to residential applications. In commercial or utility-scale installations, the use of central inverters is typically preferred, as they offer certain advantages such as higher efficiency, easier maintenance, and reduced installation costs. Therefore, the selection of the appropriate inverter technology must be made based on the specific requirements and circumstances of the installation.
This is great insight, Christopher - thank you!
'connect them in series' (4:00) - no, you wire them up in parallel. Excellent information, and food for thought.
You’re right, Mike. AC connections are always parallel. Silly error.
@@GaryDoesSolar Slip of the tongue- we all do it...
Hello, Gary! Very informative, as always. Two points relevant to home solar, at least in Latvia: 1) Power balance between phases in 3F connections to the grid must be maintained, since most of the time home solar is feeding into the grid. It's very easy to construct a microinverter system with power imbalance between phases. E.g. last autumn I received a quote from well-wishing microinverter installers, who proposed my system as 4KW+4KW+2KW connection to the grid. They did not care about the feed-in balance. I did not go with them and installed a string Inv, that takes care of that balance. Now, from March 1 this yr, this is to be guaranteed before commissioning the system. Had I went with their offer, I'd have an energy inspector knocking on my door rather soon. 2) Energy storage in home systems are becoming a necessity. Microinverters do not live well with battery systems. Batteries are the rising trend on our shores, actually energy autonomy is (partial or full). Battery solutions with microinverters become more costly, than those with hybrid string Inv, not least because there are AC-charged batteries and simply more devices involved.
I chose a string Inv over a hybrid Inv with batteries for cost reasons. Already now I consider it my huge mistake. I wonder what microinverter owners think about energy storage?
Thanks for the kind words, Andris - and thanks also for taking the time to comment with all this detail. You've given me some homework to do - balancing on 3-phases is not something I've considered before.
Can you say a little more about your comment, "Microinverters do not live well with battery systems." please, as I'm thinking there should be no issues. Interested to learn...
@@GaryDoesSolar I have Enphase and a MultiPlus battery inverter controlling 3x Pylontech US2000C’s. No issues here. While it is true that the worst case for efficiency losses is converting DC/AC from panel to inverter, then AC/DC for charging the battery, then DC/AC for discharge, it’s worth considering that any spare energy would be going to the grid at a pittance anyway. Although you could charge your car on the AC output, it’s still going to get converted back by the onboard charger. You can’t win all the time I guess 😅
@@willmorgan6867 Ah ok, got it - thank you!
Interesting. Because the inverters do not set the power.
The power is set by the load, that is what is consuming the electricity you feed into the grid, and that is something you do not control.
The power rating of an inverter does not mean that is the actual power that is transmitted down the cables at any instant in time; the power rating of the inverter is the maximum power it can deliver.
So, you could have 3 inverters rates at: 5kW, 5kW, 2kW.
And if the grid is consuming 1000 watts on all 3 phases, (a perfectly balanced 3 phase system) then there is no problem as all 3 inverters are able to deliver enough current to feed each 1000 Watt load.
The problem is going to come when the grid demands a power of 3000 watts on each phase - 2 of the inverters can deliver it and the third can't.
But technically this is not balancing on 3 phase which is actually load balancing to keep the neutral current to a minimum, this is just ensuring the each inverter is the same maximum power rating.
A 2KW imbalance on a domestic property is nothing. If there are three properties on your street each on a different phase, and one turns on a 10.8KW electric shower...well, you see what I mean.
A plus to micro-inverters is that you do not need to deal with high dc voltages, expensive HV thick high voltages cables and DC circuit breakers. I have installed solar panels with micro-inverters in my house, in Brazil, since 2018 and it has been performing flawlessly since then, I am very happy with it since expanding is just a matter of adding more panel and inverters.
This is great to hear, Claudio! Thanks for sharing :-)
I always enjoy your videos, Gary. You strike the right balance between technical detail and effective communication to laymen like me. I wish I had access to your videos when I installed my system 4 1/2 years go. Fortunately, I had a good contractor who worked with me to design a system that has served me well - with the exception of the SolarEdge inverter that needed to be replaced after four months with two weeks downtime during the height of our intense desert summer. Recently, I observed my daughter and son-in-law going through the process of getting bids on a system for their house. I advised them to request Enphase micro-inverters despite the slightly higher cost. It
Thanks for the kind words, Richard. Sorry to hear about the troubles you had with your SolarEdge setup. And at the worst possible time too! I hope all goes well with your daughter and son-in-law’s own installation 👍🏻
@@GaryDoesSolar It turns out that my next door neighbor had a SolarEdge inverter fail in the first year of operation. It was promptly replaced and, like mine, has performed flawlessly since. However, this experience was a major reason why I recommended micro-inverters to my daughter and son-in-law.
I did a great amount of research before buying a micro-inverter system (USA). Still, you covered a lot of important points that I hadn't come across. Bravo!
Thank you for taking the time to comment, Axion - and great to hear you have a microinverter solution! Thanks for the kind feedback on the video 😀
Greetings from Australia. Thanks for the video, Gary. This is, without a doubt, the best video I have ever seen about solar installations. You have a new subscriber.
Greetings! 😀 And thanks for subscribing. I’ve never been to Australia, but do have an ever-increasing number of conference calls with companies out there. One day 🤔 😎
This comment section is an endless battle of fighting misinformation and misconceptions. Keep up the good work!
Haha - thanks! :-)
8:48 I'm very happy with my microinverters. 8 years without a failure of the microinverters themselves (enphase m250). Although I did get a squirrel build a nest and chew through one of the wires. As you mentioned at this point in the video, I have 36 panels and it only dropped my production by 1/36th. Hardly even noticeable. I just waited a month or so for nicer weather and repaired it then. Besides not losing power, the other nice thing was the wire to the panel that was chewed through and laying on the roof only was carrying 36V from the one panel rather than hundreds of volts with them all in series risking fire.
That sounds great, Scott! And 36 panels? Wow! :-)
@@GaryDoesSolar Keep in mind, they are 8 years old, so a 280W panel was pretty state of the art then.
A BIG advantage of micro inverters if you don't want the DC for batteries is that you can slim down all your cables and/or reduce DC voltages as you say. I find multi hundred Amp DC positively scary and love micro inverters, but I can get at my panels so I don't need to care if the inverters fail more often - and 10 times as many inverters will create 10 times as many equipment failures on average.
Thank you very much again, and especially thank you for the hint towards the labor reimbursement program. This is good to know, even though it will not cover the whole costs if one of the inverters needs to be replaced. But who knows how often and if this will happen at all. Somehow it seems way less likely than with a central inverter.
You're most welcome, Annette!
Another very well made video Gary 👍
The biggest thing holding back microinverters is the lack of competition. The only game in town is Enphase so price competitiveness is currently very limited. It'll take another big company to develop their own mass consumer microinverter solution to change the narrative.
Thank you so much! They continue to be hard work to make, but feedback like this keeps me going :-)
You're not wrong about the lack of competition in the microinverter space. I too, hope that will change before long. For example, why doesn't SolarEdge jump in?
@@GaryDoesSolar Western companies need good margins to justify R&D/product development.
I think it's more likely that eventually a domestic Chinese company will be the ones to offer an Enphase alternative as they won't have US executive/sales/marketing salaries to support.
@@KoRWraith You could well be right, in a global environment, non-Chinese OEMs need to come up with good strategies to compete!
What about a grid that is off more than it is on? How will essential loads be powered? UPS and batteries?
Hi,
Yes. that could be an issue in the future. There were other manufacturers around but it seems like microinverters are not that interesting for the solar builders (as they can sell way less engineering).
Still: It's a good sign the solution slowly but steadily gets more momentum. There will be other companies jumping on the boat sooner or later.
Everyone I have been talking to really likes the microinverter solution once they did get what it's about.
Tobias
This is got to be the most informative video I have seen on micro inverters. As I am building a system now with micro inverters.😁
Thanks Harold - that’s such great feedback to receive! You might also like to watch this interview I did a few weeks ago with Enphase: ruclips.net/video/kGCKarB7fnI/видео.htmlsi=dDbrA-U_nkKpI-hG
Hi Gary. I've got 18 panels (6.9kW) with Enphase micro inverters. I chose the system because I have a large oak tree (protected) that produces diffused shading in winter/spring once the leaves have gone (lots of shading in autumn!). I did watch your video on shading and bypass diodes but I'd already got the system by then and could see that they do actually produce a continuously variable output per panel across the array as the sun moves. I also like the idea of having 230VAC rather than huge DC voltages on the roof and, as you say, no voltage if you throw the isolator. The other advantage, that you hint to at the end, is that an AC coupled system is much more flexible when it comes to adding battery storage as well as allowing both solar and battery power to be used to supply peak demand (when the sun's shining) which could even power a 7kW EV charger. There is a limit to the number of panels that can be directly connected together (which I think is probably to keep it within 20A to protect the cable) but that is easily solved with a small CU in the loft.
Thanks for the detailed comment. Yeah, I would have spoken more about batteries on a microinverter-based setup, but the video was getting a bit long. My plan is to do a follow-up video shortly covering that and other feedback I've received through the comments. I'll remember to add in from the points you make here too - thanks! :-)
But you need soooo many micro inverters and they are expensive
Panels produce dc power. Batteries are dc. You’re converting the power 3 times instead of once. You bought the hype it’s not actually any better
Fantastic article Gary. I am biased as I install Enphase microinverters. They are the most reliable system around and from a company that actually gives a damn about it's customers. Why bring high voltage DC into your home when there is absolutely no need. AC architecture is the only way to go.
Cheers Andrew - yeah, there are a lot of benefits! My main concern is the cost to replace a failed unit - especially on a two-storey property. Will the warranty cover the majority of this…?
@@GaryDoesSolar Hi Gary. I am obviously talking as an installer. As I type we have fitted just over 7000 micro inverters and we have had one fail. We have a duty of care to look after our clients and keep them happy and keep them referring business to us. Enphase replaced the microinverter by sending direct to the client. We then arrange to install at our earliest availability. This was within 2 weeks and bear in mind the remaining panels are all still working as there is no single point of failure. Now what does that cost me? Approximately £250. We have our own tower scaffolding that could be used on 90% of remedial work. Remember, we know exactly which micro has failed and therefore dont need full tube and clip scaffold to go "hunting" for the point of failure. If we needed full tube and clip then this would add about £350 to £550. So, who pays for that? Me and I can recover some costs from Enphase. So lets keep the number simple. Lets say the average install is 12 panels, we have therefore installed 583 systems. If the one failure cost me £800 to replace (it didnt) then that accounts for £1.37 per installation.(583 x 1.37 = £800). Its not worth worrying about. I very often say "I dont wake up in the morning wondering which Enphase installation has failed today". I cant say that for other systems.
Now if we look at failure rate with some other manufacturers. One who shall remain nameless has in two years had approx 30% failure rate. They also have 100% failure rate due to recent server updates and customer complaints about none access to systems. This is inverter failure so no roofer required, just a sparky. Average cost to me £250. We only installed about 30 systems before I pulled the plug. We ripped the system apart and were appauled at the build quality. So, those failure rates have cost me approx £2250. Not good. The Supply of Goods and Services Act say that I am responsible and therefore the more of this cheap system I install, the quicker I risk going bust.
Please also remeber that we are not just talking about Enphase micro's here. There is the Q-cable.This cable costs about 20 times that of 4mm DC. Why? Because it is built to last. Enphase is more expensive than a conventional string but you oly have to look at the quality of the materials to know why. I havent even touched on the battery system but can save that for another day.
Recapp; no one calls me to say "My Enphase system isnt working".
Regards, Andy
PS Joti from Enphase has been trying to contact you to see if you would like to come out on an installation.
"String inverters typically last only 8-12 years" - where did this data come from?
Enphase started producing 2008 ->
I like micro inverters but its just too early to tell they last ±25 years.
Imagine your micros start to fail after 25 years. Will you order somebody to change them one by one as they go off? Are you happy to buy new micros + installation as your old panels could still have +5 years 80% lifetime left?
Very nice channel Garry and good information,thanks. Kudos from the early adopters part.
Hi Mikko, thanks for your kind words about my channel - it takes more hours than I would like, but feedback like this keeps me going! :-)
In answer to the points you raised:
Lots of sources on string inverter lifetime data, for example: www.pv-magazine.com/2022/10/03/how-long-do-residential-solar-inverters-last-2/
Before I got into a career in mobile, I developed software for semiconductor burn-in/test systems - essentially abusing computer processors and memory chips with thousands of hours of harsh environmental situations (heat, humidity, vibration etc.) until they die. From this data, you can make fairly accurate estimations on expected lifetime. You don't need to wait 25 years.
In terms of practicalities, the world will have changed a lot in 25 years - I'm sure that by then, you'd simply replace your entire solar solution with a completely new one.
the failure rate are very skewed, they installed 3100 in five years, so that is not a rate of 3 failure per 3100 in five years. only one of the installs has been around for five years, and the very last install was only around for one day. since this is from startup i would guess about 2 percent in the first year and 30-40 percent in year 5 as interest grew. the failure rate math is therefore very very very difficult.
I have an older ground-mount string-inverter solar system, comprised of 24 x 280watt panels (online in 2013). I then had a second system installed with 23 x 335watt panels with micro-inverters on my barn roof in 2020. The 23 panel system consistently outperforms the ground-mount system, not just because the panels are of a higher wattage, but because the micro inverters can handle the shading of trees or low sun-angle shadows in the winter months much better than the string inverter can. It's really noticeable seeing the whole system have to go down to the lowest denominator, when the micro-inverter system still has maybe 75% of it's panels running at top effectiveness, as they're not shaded. I am still on the original string inverter, and it is now several years past it's warranty. When it does fail, I am really tempted to consider converting the ground-mount system to micro-inverters for the second half of their expected lifespan.
Thanks for taking the time to comment - this is great real-world insight - and great that your string inverter is still chugging along :)
Since microinverters currently clip at 388W wouldn't you choose cheaper lower wattage panels to avoid this? Is there a reason for this 388W limit and will it change in the future? I appreciate based on your explanation that it doesn't make much difference to the overall output, but these seemed obvious questions that you didn't cover in your video. Great video, love your straightforward no nonsense factual style of presentation. Keep it up!
Hi Viv, the 388W limit will be different depending on the actual microinverter, and I'm seeing that with successive newer products, this limit is going up each time.
Yeah, you could choose lower wattage panels (saving cost perhaps), to combat.
Finally, thanks for your very kind words - I really appreciate getting feedback on my videos :-) I'll keep them coming...
Remember that a panel is only going to make peak wattage under ideal conditions. Only when the panel is pointed directly sunwards on a clear day. You're seldom going to actually see that much power.
Again, this is a very thorough and well-explained motivational video to choose a micro-inverter PV system setup.
Thanks for the great feedback, Adriaan :-) Yeah, I'm really warming up to microinverters!
Always very informative Gary! One thought about system design is that power electronics don't necessarily have to be mounted underneath the panels. They could be mounted in the loft. Lots of advantages: Easy to replace faulty modules without scaffold, easy to inspect connections, protection from damp environment. One disadvantage is summer time loft temperatures. I don't know how they compare to under panel temperatures, but I think I might do a temperature survey this coming spring time.
There's typically about a metre of cable with each panel, which should be long enough to slide under the roofing felt overlap and connect to a power module mounted to the rafters.
You touched on rapid shutdown in the event of fires. I read on the efixx youtube channel that there's about 10 rooftop solar fires a month in the uk.
ruclips.net/video/DZeY6q5lscY/видео.html
That will no doubt increase 10x as solar continues towards mainstream adoption. It might be worth exploring the causes of fires (if any cause can be determined after a fire), and how these causes can be designed out of the system. One thing I discovered during my fault finding process is that modern junction boxes for the bypass diodes are filled with a potting compound. This not only seals the connections from moisture, but it dissipates heat generated by the diodes a lot more effectively. I've always wandered how those diode legs in particular were rated to 15 amps of current, when the diode legs had a much smaller cross sectional area than the cables connecting the solar panels.
Periodic inspection of the panel wiring is recommended under wiring regulations. However with MC4 connectors being under the panels, they are almost impossible to inspect without actually dismantling the system that you're supposed to test! That then loops back to my idea of having all connections in the loft space.
Thanks for the shoutout by the way!
Thanks Anthony - hope you liked how I put your segment together :-)
Aside from potential future roof leakage issues, the idea of having the microinverters within easy access makes a lot of sense (as easy as accessing them on a ground array!)
Unfortunately, it wouldn't be an option for me though as our loft was converted into living space 10 years ago :-/ (You'll see my roof space in the next video hopefully)
I did see some photos of the Enphase microinverter internals and they was filled with potting compound too - I guess that's how they manage to survive so long outside!
The fire safety aspects could be a real problem for string inverters going forward. In most states of America, they just mandated MLPE and that was that. I can see the same thing happening here in the UK too.
@@GaryDoesSolar MLPE ???
Sorry @@allan4787 - I should avoid using acronyms. It stands for Module Level Power Electronics. Here's a link worth reading: cdn.ihsmarkit.com/www/pdf/0822/Module-Level-Power-Electronics.pdf
That'd exactly how I installed my EnPhase micro inverters. DC cables pass from each panel through in to attic space. Inverters are screwed to a mounting rail. That was for my first 10 panels, then I switched to using secondhand micro inverters for around half the price. I think there is a good potential market for reclaimed solar equipment....If the price is right.
I checked my loft temperature during June's heatwave. It was only 2 degrees warmer than the outside temperature. I must admit it felt much warmer but who am I to argue with what a thermometer says. Inverters are pretty reliable bits of kit. In the factory where I work, we have thousands. And they are running 24/7/365. Very rare for one to go wrong. And some of the machinery is well over 25 years old. Same electronics.
Thank you very much for the neutral and unexited fact based presentation. Such videos are of very high value.
I really appreciate that - thanks for taking the time to comment :-)
Hello, ive personally been in the PV world since 2014 and have done micro inverter systems on residential homes all the way up to 27MW utility scale projects and when it comes to the residential market the Enphase micro inverter is hands down the best there is out there. after installing thousands of micro inverters i have personally only had a handful fail. something else most people dont consider with PV setups and with micro inverters you can always put a module (panel) that's larger than the output of the microinverter. this will start you production earlier in the day and produces later in the day expanding your power production window. to sum it micro inverters are superior in so many ways (String/central inverters fail very often Solar edge 1-3 years 50% fail, SMA 5-7 years 50% fail) $$$ lots of money to repair/replace
one con about the Enphase micro inverter is your a true survivalist these will not work for you since they require the 60hz sign wave (if your in the U.S) for the inverters to start outputting power. that means no off grid systems charging batteries and you cannot run off the receptacle that a lot of string inverters come with now a days when the power goes out. so if the grid is down so is your PV system no matter what (Unless you spend a lot of $$$ on a sign wave signal generator)
im not an engineer or anything special just installed and repaired thousands of systems over the past 9 years and have formed my facts/opinions from that.
Thanks very much for taking the time to comment, and also for this great insight. Many people dismiss microinverters but they don't get the point that their failure rates are incredibly low, especially when looking at a timeframe of 25 years (like you would with other building attachments).
Thanks Gary, a very insightful video. I especially liked your analysis of the mass-market viability of micro-inverters. I never thought of that aspect myself. (And, sure, i fit your 'early adopter' profile exactly!! 🤓)
One advantage of micro-inverters that you haven't mentioned is cable losses. To transport the generated power from the panels to the house/storage, there's going to be cables involved. With string-inverters, this will be DC power, and the current-per-string can be significant on sunny days. The panels i have can generate 9A peak. To avoid significant losses in the long-ish cables, you'd need at least 4mm-sq or rather 6mm-sq copper cables. That is a significant, and expensive, amount of copper.
On the other hand, micro-inverters generate 230V AC (RMS) _before_ transport. Taking those Enphase IQ8 inverters as an example, at peak capacity of 388W, that would mean that _each panel + inverter_ injects 1.7A into the AC bus. That means that with 9 panels + micro-inverters, you're still under 16A RMS, and you can use very regular and affordable 2.5mm-sq cable for the AC bus. And if you have more than 9 panels, run as many parallel AC bus lines as you need. The cable is still much, much cheaper than the type you'd need when using string-inverters.
Thanks :-)
I know there are many people out there who might instantly dismiss microinverters, but in line with the great points you raise, if microinverters were really not fit-for-purpose, then I'd like to understand from those people why Enphase, the leading manufacturer, is going from strength to strength?
This is all well but you are missing one crucial problem: to charge your home battery you want DC not AC. A hybrid inverter that feeds DC right into the battery and converts from both panels and battery to AC is much more efficient than a battery with separate AC inverter. On top of this a central inverter is much more efficient than microinverters are. Putting this all together the difference is huge! The solution to the problems you describe are optimizers which adjust the DC voltage of individual panels in a string. You don't even need them on every panel. So sorry to say that while in isolation what you say is right in conclusion it is wrong!
Hi Ludwig, thanks for taking the time to comment. With a microinverter system you can use any AC-coupled battery (e.g. Tesla Powerwall). True, there are additional conversion losses, but when I mapped out typical charging/discharging of both DC-coupled and AC-coupled batteries, there wasn't much real-world difference.
What sources do you have to support that a central inverter is much more efficient than microinverters? I'd be interested to see those.
I'll be making a video on optimisers soon - like other solutions, they have pros and cons, which I'll cover.
However, I stand by everything I said about microinverters in my video. You don't need to be sorry about that.
@@GaryDoesSolar There is plenty out there on inversion losses. Microinverters will lose you 5% easily, and this is at their optimum power, so likely much more in reality. A great string inverter has less than half of these losses. Then there are cabling losses. Not only is the voltage often much lower than with DC strings, but the cables unlikely to be large enough to avoid significant cabling losses when high current is running. You need an awfully large cable to generate 10kW of power on a roof with microinverters! And then there is the AC->DC->DC->AC conversion loss for the battery storage which will be easily 5 to 10%.
People also overestimate how much better optimizers and microinverters will fare with shading. They fare hardly better. The reason is that modern PV panels shut down part or all of the panel in case of partial shading. So the impact on the entire string is far less promounced than it was in old times.
With very complicated roofs and patches of panels here and there microinverters may be the way to go, but otherwise they are unlikely to beat a more conventional setup, at least when that has been done well.
@@GaryDoesSolar Another issue that you are ignoring is multiple phases. In the developed world most residential houses run on 2 or 3 phases. With micro inverters you have to choose one phase, though you could potentially supply 2 or 3 phases in parallel by different micro inverters. However, they will not be able to balance the load between the phases, as a multi-phase strong inverter does. So you will find that sometimes you are buying power from the grid because one phase is short of power while in total you are actually selling power! This is not efficient, also considering that buy and sell prices are vastly different.
@@ManfredvonHolstein You haven't provided any sources to show string inverters are more efficient than microinverters. The battery topic is separate to that.
With regard to shading aspects, I cover those extensively here: ruclips.net/video/9GvhDhCSJgo/видео.html
@@GaryDoesSolar Just look at the ratings of individual inverters and you will see. Also there is lots out there on cabling losses - in fact it is so basic you may just need to read up on the electric basics. You can also estimate cabling losses with online calculators - plenty of them out there. The overall point is that only because a microinverter may look nice in isolation it doesn't mean it will be the best solution in a system. It very often won't be, and that's also why they are not used much.
Seemed a good summary of the issues. Microinverters evidently the way to go. On roof connections more simple. Analysing performance and fault finding should be simpler. In general, many identical things are more easily dealt with than fewer customised things. I'm waiting for the solar panels to also provide the weathertightness of the building.
Yeah, at first sight, having complicated electronics on a roof exposed to all sorts of weather over 25 years sounds like a really bad idea, but I note that manufacturers like Enphase carry out a massive amount of climate testing, to make sure their products have the best chance of survival over that time
@@GaryDoesSolar I suspect that 230V connections are more reliable and more familiar to electricians. Make the LV DC as short as possible and as standardised as possible.
Micro inverters are a waste of money. Convert the panel to ac, then convert it to dc, then you put it in a battery. now you have to convert it back to ac to use it. I see a lot of losses here.!!🤔
Use an AC battery
Carl, that’s exactly how a Tesla PowerWall operates.
@@GaryDoesSolar That leaves dependance on a grid.!!🤔
@@ozzieinfrance Ah Ua yuck Gorsh.!!🤣🤣😂
An MPPT charger does a similar conversion: convert to AC, match battery voltageand current, convert to DC. It is true that an MPPT charger does use a higher internal frequency and so can do the same job with much smaller components. Also, the whole thing is built as a unit and so inverter and charger are matched. What might be interesting is micro inverters that run at a higher frequency than 60Hz with purpose made chargers on the battery end. The transport voltage could 240V while still using standard, well known, cheap, House components such as breakers and wire. There would be less loss in the panel to charger wiring (this may be true even with a 60Hz micro inverter).
My system designer is specifying Enphase IQ8A inverters to mate to my 31 Q Cell panels (12 east and 19 west) aside from all the points you mentioned I was informed the micro-inverters can start up with much earlier than string inverters. I might get an extra hour each day of collection at the beginning and end of the day. We did discuss Enphase's SunLight Only option, but since we plan on adding batteries in the next 12 months (hopefully a tesla Powerwall 3) I opted out of that functionality.
Sounds great, Thomas. Good luck with whatever you decide and I'd be very happy to hear how you get on :-)
Yeah, let's hope the PW3 appears on the horizon soon!
Why would you want a third party to monitor your private system? People have too much trust.
Yeah, these kinds of systems are not for everyone, but I do believe it allows the supplier to quickly diagnose any problems in-life. Most new cars in the last few years already have such monitoring.
I'm all for privacy, but what are you worried your solar installer is going to be able to do by being able see your generation stats?
@@shaunclarke94 who knows what could happen. Things could stop working after an update and you're asked to pay for a further update.
Or maybe a new TAX on energy you generate.
@@1960ARC that would be done on the metering side.
I won't upgrade my Litterbox for that reason. It HAS bluetooth to talk to my phone, but it doesn't use it except to talk to Litter Robot to assign an IP so the box can tell them when my cat takes a dump and then they can tell me.
If i'm not home, knowing the box is full does me no good. The bluetooth is more than enough range to ping my phone without notifying the NSA.
Thank you for the detailed explanation on microinverters. Based on what you laid out it is clear to see where the advantages are and I learned a lot in the process.
Thanks Chad - glad to helped you out in your research :-)
As panels degrade you can add an extra panel ezi pezi, and maintain the full production.
Or as you get a second EV add extra panels.
Great work 👏 👍 👌.
'Low' voltage on a metal roof with a roof verandah is a great feature.
Thanks Stephen - totally agree! Glad you liked the video - it took a lot of work, but I'm pleased with the result :-)
Hi Gary awesome videos, great stuff, I think your mostly right, but for me the cost of buying enphase micro inverters cost more than buying multiple string inverters
Hi Tim, yeah - you're right. The costs need to come down so they're more comparable with other solutions. Hopefully, that will happen over time, but some decent competition to Enphase would certainly help!
Great video very informative. One thing to take into consideration when it comes to cost. You still need another inverter for the battery. This means still a inverter that needs changing. Most solar system are fitted with one hybrid inverter for solar and battery
Good point - I'm thinking of doing a follow up video in a few weeks, in order to include all the feedback and insight I'm receiving, including from yourself - so thank you for that! :-)
If you have an existing inverter/charger could you use the output of the microinverters as the AC charger input?
Great video Gary, thank you for putting it together. You have convinced me that micro-inverters are the way to go. I like the approach of each panel is its own individual element and the management at that individual level is key. Cheers
You’re most welcome, Luke. I’m hoping to release a video interview with Enphase soon too…
This is the best solar electric video I have seen. It gives all the good and the bad of harvesting solar electricity. Keep it up!
Thanks :-) I try very hard to be objective in every video I make...
Well done Gary... watched the lot.
We have extension plans for our house going through at the minute and solar + battery will be installed. However, I though I had a solution figured out but after watching this I'm not sure...
Hi Phil - thank you for taking the time to watch all my videos. I hope you managed to get a lot of value out of them. And apologies, I've given you more to think about!! Hope you settle on a great solution :-)
Enphase system owner here. It’s a great system and I really love it. Would be great if Enphase were more competitive on their pricing structure. The cost premium for an Enphase system over a traditional string inverter setup is rather high. For example, here in Australia a string inverter 6.6kw system would be around $6k-$7k with good components and reliable panels. The same thing but with an Enphase IQ7A system will cost around $11k. That’s a fair whack for the benefits that come with the Enphase system. I have a lot of elderly people as neighbours, retired etc… I couldn’t recommend the Enphase system to them unless they either had dynamic shading issues, and/or had the money to make such a decision.
Yeah, Enphase pricing is still quite high compared to string inverter solutions, but I'm hoping that prices will reduce more in line before long...
Fantastic data and information, presented in the most boring way/tone possible. This video is a great cure for insomnia.
Thanks for the feedback 😀 It doesn’t correlate with countless other comments I get saying the opposite, but I’m also happy to help those with insomnia 👍🏻
I'm a great fan of panels on a ground mount if back garden faces south and you have a big garden. Mine are tiltable and easy to measure individual panels if suspect a fault.
Yeah, that's pretty much the ideal scenario :-)
As always Gary a great explanation and explained exactly why we went with microinverters, having 3 panels on the house (due to shading restrictions) and 10 panels on the garage 30m away. Splitting the installation across two buildings gave us much more flexibility. Another benefit is the Enphase Envoy is tiny compared to an inverter. I've only had the system for a few weeks but been very impressed so far.
Sounds great, Paul. If I had my time again, I would certainly go for microinverters... :-)
@@GaryDoesSolar If your installation is not installed yet, it may be an idea to see if your suppliers/installers can go with microinverters for you. They may put your actual installation back but you say that now you "would certainly go for microinverters". It's worth seeing it they can accommodate your new requirement as requirements change up to, during installation and post install as more practical knowledge comes to light.
@@dapperdynamicdavid I did consider doing that, but in the end I decided against. I actually want to get deep experience of the GivEnergy products I've ordered) as they seem to be geared for dynamic energy tariffs - a topic for a future video I want to do.
Hi @CodeMonkey69 - what battery did you install if you have one? And is it DC or AC?
@@EngineerLewis 2 x 8.2kWh GivEnergy with an AC inverter.
Brilliant channel and in depth analysis Gary. I'm finding it difficult to decide between Micro and string inverters and just when I was convinced another question popped up.
Conversion loss... Microinverters will suffer a fair loss when coupled with battery backup?
Panels to Microinverter DC - AC loss, AC - DC loss when charging up the batteries. DC -AC loss when using battery storage?
With a hybrid string inverter you'll only suffer the conversion loss once?
More food for though?
Thanks for this great feedback, Jack :-) Now, you're totally correct about the difference in conversion losses between AC and DC Coupled batteries - but when I model different scenarios with my utilities, in practice I've found it doesn't make too much difference in the results, so I (personally) wouldn't make a buying decision for AC or DC Coupled based on that fact.
See my video here, where I talk about DC and AC Coupled battery operation and losses here: ruclips.net/video/x83t1iCMXxw/видео.htmlsi=ftHdXYE5e5oD0BAR
Hi Gary. Keep up the good work
Cheers Patrick - thanks for the great feedback! :-)
Gary, thank for a very informative video, it has given a new insight for our future solar PV installs. Thank you for your time.
You’re very welcome, Anthony! 😀
Very well explained, I like the logical reasoning you use!
Thanks very much, Tony! That means a lot to me :-)
Great, concise, and lucid explanation.
Thank you! Great to hear my videos are coming across well :-)
Really interesting video. I think we need to bear in mind that Australian weather is not the same as the UK, so we can be confident that the products cope well with heat, but I’m not sure we can say the same for cold and damp winters. They may be brilliant in our climate, but we cannot assume that from the Australian data
Thanks Billy. Yes, good point. So my thinking is this:
It's true that the two data sets I cited are both Australia, but the Enphase quoted failure rate (0.05% over 25 years) will be a global rate. I'll see if I can get a breakdown of that rate.
Enphase do a lot of climatic/burn-in testing of their products - here's an example video (check the section at 2m4s): ruclips.net/video/mq3NyIizlu4/видео.html - early in my career, I wrote a lot of software for these types of test systems, so I know how effective they are at weeding out any long-term failure scenarios (like cold and humidity, as well as heat).
Enphase rules with great quality and also customer service and warranty 😊.
Yeah, they're showing the rest of the market how things should be done :-)
We currently sell wifi controlled micro inverters for 'balcony' installed systems for condos and apartments. Its an affordable option for those living in smaller abodes. The installation is so simple that anyone can do it.
This is great to hear and supports my view that microinverters have a lot of benefits over other solutions. Thanks for taking the time to comment :-)
@@GaryDoesSolar I believe the adoption of micro inverters for a mass roll out situation is likely as long as there is good govt policy and support for it. Things have to change drastically in the UK for that to happen!
Thank you for yet another excellent video!! One nit that’s been bugging me is this is the second time I see you plot 100% power output on a chart. In this case 415 watt output from a 415 wp panel. Does anyone actually see that in real life? Maybe I have grown too pessimistic… It makes the clipping even less of an argument.
HI Peter, so, my panels are 415 watts each and even now (in November) if it’s bright sun midday, they produce that amount of power 👍🏻 My array is South-facing near Oxford in the UK.
@@GaryDoesSolar Thank you Gary.
Superb analysis
Thank you! That’s great feedback to get 😀
Hi Gary, really helpful, thank you. Really like to know more about the micro inverters on the market. APsystems look particularly interesting, with some models having lower startup voltages and higher clipping levels.
You’re most welcome. Now, the only microinverters I rate are the ones coming from Enphase.
For some reason I have not had very good luck with microinverters. Over 4 years I have had to replace 6 out of 31 microinverters. And it has been a pain in the neck to replace after each failure because the failure has always ocurred during very hot weather. If I had to do it again I would definitely go with a couple of string inverters; particularly with new panels that are equipped with diodes that solve the series problem.
Thanks for sharing this Dave - and sorry about the problems you’ve been having with microinverters. Do you know if it’s actually unit failures? I ask; because sometimes it’s due to the wiring and connectors not being fitted properly.
As always...The font of all solar knowledge...Appreciated...Another great video :)
Thanks David - much appreciated.
Excellent, I'm sold on this.
Cheers for the feedback, Greg! :-) Microinverters aren't for everyone, but I do believe have an important place in the future of domestic solar.
There are so many permutations that it's tricky to make decisions. I have quotes for a 16.7KW multi array system with battery on grid. I live near Sydney Aus. I have 3 phase power. One quote is for 2 Sungrow multipoint string inverters and 2 optimizers to 2 slightly shaded panels. The second quote is for 38 Enphase microinverters. On trying to analyse and compare, I found myself in the weeds, confused, dazed, divided and conquered. Although videos like these aim to help, they really don't because they raise more questions than they answer. It is after all electrical and electronic engineering. So anectdotal evidence from installers aside, be they well meaning. I am choosing the string inverters. Why? Price.....with the difference I can buy 2 new inverters when they fail. Building is 2 storey........and Nothing lasts forever and 25 year periods are purely academic and meaingless in real worlds....and lastly....just a gut feeling that when the discussion gets complex and polarized, my solution, whatever it is, is the right one and the best. Cheers and thanks for the vid.
You're most welcome re. the video - and I know what you mean about answers and more questions resulting!
maybe nice for shading issues and simplest setup for installers. outside that, plenty drawbacks. Enphase inverters are power limited to the latest large panels. Cost of a single micro inverter with limited output is 1/5-1/4 the price of string inverter with 10x power. I also haven't heard seen a micro inverter for backup power mode.
I don't think microinverters add much value wrt shading, except in particular circumstances (outlined in the video). Costs of microinverters today are certainly an issue, but hopefully they'll come down over time.
Regarding backup power, I believe the TeslaPowerwall can provide this - it is an AC-coupled battery, allowing it to be combined with a microinverter solution.
@@GaryDoesSolar you have a point with the Tesla Powerwall but then it is an excellent system which is even more expensive and now it is only available to buy with a Tesla Solar system purchase. I like the simplicity and robustness of microinverters, I guess it becomes superior to places with high reliability grids, like less than one hour power failure every ten years and good net metering.
Very good video that deserves much more attention! Thanks.
Hi Geert - thank for taking the time to comment. I really appreciate the feedback :-)
Another very descriptive and easy to understand video. Thank you
You're most welcome, George :-)
Fantastic video, many thanks for all that excellent information, calmly presented.
Thanks Nick - very kind of you to say :-)
Thank you for good infomation. One question that still prevent me from using micro inverters is: how do you prevent electricity generated by solar panels from flowing back into the utility line?
You're very welcome :-) The controller unit for a microinverter solution (for example, the Envoy unit with Enphase) should take care of that for you, by instructing the microinverters to curtail their production.
thank you. explained in clear perfect english.
Thanks Fred - great to hear! :-)
Glad you are so excited about Enphase Microinverters. Too bad you didn't mention that the advantages only outweigh the disadvantages until you want to integrate storage. Since only the integration of AC storage is possible, the costs are far higher than when using a Solis hybrid inverter S6-EH3P(5-10)K-H-PRO, for example, which 4 strings and a cost-effective DC storage can also be connected. In addition, there are the significantly higher conversion losses with AC storage.
Helmet, your argument would mean *nobody* would buy AC-coupled storage irrespective of whether microinverters were used or not. And as the market clearly shows, that’s not the case.
You need to lend your voice to a nature documentary series, ahhh yes, got the factory integrated Sunpower panels with IQ8’s booked in to be installed in a few weeks💪💪
Haha - thanks Chris :-)
And great news about your installation. Hope it goes well!
Sounds like a wonderful idea until a fault occurs then the trouble starts. First get your sparky to find why the rcd keeps tripping. Next scaffold the house to find the faulty micro inverter which can be very time consuming and inaccessible. Replace the faulty micro inverter and send the customer an invoice for two days work plus the scaffold. Stick to the standard string inverter and save yourself a lot of hassle and expense. My string system has been installed for 11 years with no trouble and always generating ! Plus the Kako (german) inverter is cheap to replace.
Hi Peter, thanks for taking the time to comment.
Yeah - until someone figures out cost-effective, safe roof access, it's a real negative point for optimisers.
HI Gary, love your videos, probably the best source of balanced information I have found.
One question I have for microinverters, is their start up in lower light levels, as I will have some NE facing panels (in the UK). A salesman suggested microinverters have improved lower startup levels.. but I am struggling to see comparative data with string solutions to validate that claim. Have you looked into this?
Cheers for your kind words. It's not something I've looked into, so I don't have any data. I hope to be speaking with Enphase soon, so I'll ask them...
Great video, I wish there was a section on the integration with batteries and chargers and how does it work and perform
Thanks. And any AC Coupled battery can be used with a microinverter installation without problem - and it will perform just as well as it would in a string inverter system.
Very useful video Sir. Pl keep sharing such videos
Hi Pandurang, thanks for the great feedback. I'll keep the videos coming! :-)
Excellent again Gary. Thnaks for all your research and fantastic presentation!
It's my pleasure, Andre! :-)
First off: i have both a string inverter and a group of enphase. Both have strengths and weaknesses. Every time there is a negative aspect to mention about microconverters like enphase (i have such a system) you leave it out: 1) the 230vac production means you have to string anyway if you are talking about 8kw+, 40-50amps requires expensive thick wiring, so string wins here as typical target voltage range 600-800V. Higher voltages equals less loss, cheaper wiring. 2) brings up second point and that is startup point. My enphase array starts later producing because i can’t stack voltage by putting more panels in series. So the sensitivity of microconverter looses from single converter. 3) my enphase micro top off in mid summer, loosing out on potential production, 4) the largere the array of pannels the bigger the price difference. String inverters are cheaper per kW production, alot cheaper. Why still choose Micro? Shading+irragular spots for small groups of panels, then go micro. If you make a 16+ panel array on a barn, always go for string inverters… this i advice from my own experience having both type of systems. Last thing: microsysteem is not cleaner, you still need to place an additional Envoy unit (which also costs 300€+)
Thanks for taking the time to comment, and also your insights from the experience with your own arrays. This will help out many.
I have had enphase microinverters for almost a year (IQ8+). No real problems but one thing I have noticed is that the more microinverters you have the slower the response time to load changes. When I only had 10 it was really fast, now with 24 it is noticeably slow.
Thanks for this insight - I didn’t know that - it seems a very important consideration 👍🏻
That is strange. Are you sure it is the micro inverters, and not the grid tie box?
Seems to me the inverters should always be pumping out the juice from panels, it is where it goes after that..... Sounds like the power company want your power more than you do.
@@robertsmith2956 Probably a combination, it was covered in EEVLOG. Its part of the control algorithm. The more you have the more it has to compensate.
@@RS-ls7mm blimey, i'll get some fosters and look for it.
Now it could be china has to give it the OK as well.
A great video Gary, thanks for sharing!
Cheers for the feedback! Very much appreciated :-)
Another fantastic video. My system is beginning to give me some good numbers. The panels on the back which are west north and beginning to get more sun. I will be launch my blog soon covering my generation numbers and mentioning this channel as a great resource. Gary, would you mind if I drop the link in a comment? I want to share my stats as I see videos on RUclips with other people showing there stats, but of course everyone is different and panels facing different directions. One last thing, and this is a bit tongue in cheek. When you logo zooms out the start, I always think it is a nod to the Scottish flag.
Hi Michael, thanks for your kind feedback. Yes, no problem sharing a link to your blog in the comments. And I'm looking forward to reading it! :-)
Excellent video. The absence of a central inverter means less space needed. The envoy is small and can go anywhere. However, we all assume internet is available or a customer is ok with having his system visible to the outside world. What happens if you only want accessibility locally?
Many thanks as always for your kind comments! :-)
I'm not sure, but the Envoy might only be mandatory for initial configuration of the microinverters. After that, you could simply disconnect it from the Internet? Maybe others have a view on this...
Indeed : you can't be of off grid, and you need to be connected since would not own your data, nor control your system.
Probably too late to the party on this one but figure there are many guys like me who are looking at this issue as we make our solar system choices.
In my case I went with a single large inverter (Sol Ark 15k with 200 amp bypass capability). I am not going to use net metering and won't be selling any power back. I am using batteries (my other discussion with you) to capture my excess power....but only to the point where the battery payback makes sense....because I can pull from the grid. The whole payback issue has to be matched up vs the cost to just take it from the grid at 15 cents a kWh. Yes, it makes sense to factor in long term inflation when looking at the grid power costs...but...here in Texas that is a real challenge. Rates have ....at times....been very stable for years...only to have jumps. So...I did most of my math keeping the current grid rate of 15 cents....inflation...for me...will be gravy and make my payback faster.
So in my case...I decided that I was more confident in the single (expensive) and highly efficient Sol Ark 15k managing 27 panels...plus...I will have a lot of excess power that will flow dc to dc into my batteries...vs the micro inverter choice.
I spent my whole career in the tech industry....including computer data centers. My issue (which I can't prove) is that I look at both the micro inverter and optimizers as points of failure. Then...if it is roof mounted or a challenge to get to...I see that as further risk factor. I don't personally believe the failure rates will remain low over longer periods of time in harsh (hot) conditions but IF they do work then my risk issue is unfounded.
At the same time, I see many of the benefits you state about micro inverters ...for me it would be the very simple concept that each panel is a little AC power plant that is easy to watch and manage. I'm not sure I buy into much of the debate about micro inverters and optimizers making the shading / power optimization thing worth the extra cost...because I think the panels these days go a long ways to doing a lot of that. Your other videos were great looking at the real impact.
Finally...and this is a hard thing for folks to consider...is...that as panels continue to drop in price....in my case I was able to get the panels for 33 cents a watt...545 watt bi facial ones...I think more and more...if you have the space....the answer will be...just add more panels?
In any case your video really made me think a lot about my setup and if I should consider changing my approach. I'm not really "religious" on any of this stuff....and....I find that a lot of the time there is not a clear...absolute answer....in part because of lack of data...lack of time for products to be in the real world....and finally....will your warranty even matter and will your suppliers even be in business when it comes time to try and get warranty or out of warranty service? I've almost discounted all the warranty stuff under the belief that most of the folks I buy from today won't be around in 5 or 10 years. Someone will be around...but...much like I treat my pool....or my HVAC systems....I will call someone reputable at that point in time to service my solar system. Now...that is probably why the big companies can make a consumer feel good....i.e....one would assume Tesla or Enphase will be around to take care of you...and...this may justify spending twice or three times as much for your system. Each person has to place a value on risk when they venture into solar and batteries today!
Thanks Scott, for taking the time to write this excellent analysis! :-)
I might be speaking with Enphase shortly, and will ask them about their view on reliability...
Hi Gary great video...do you know if the Enphase IQ8 is available to buy in the UK?
Thanks :-) Now, I'm not seeing them in the wholesalers yet, but it can't be too far away... :-)
Best I've found is Soly UK who are using Enphase IQ8MC and 435W panels.
I have enphase inverters. Have 17 and 7 of them needed to be replaced over 6 years. Also, the brain has been replaced 4 time. System currently not working and enphase admits they are stumped on how to fix. I’d recommend getting one large traditional inverter.
Sorry to hear you’ve had such a bad experience with microinverters. If Enphase is stumped then that’s saying something! Do you think there is something about your particular installation that is causing all these failures? Has Enphase indicated to you what the causes of the failures, if they have the returned units and associated data?
@@GaryDoesSolar they have changed the inverter generations over the years as well as several upgraded router hw over the years. Additionally, they have updated the FW on the router. This latest FW update doesn’t play well with older generation HW. I have a mix of several micro inverter hw generations since they have been replaced as old ones die. This combo of multiple HW is a nightmare for them. Even if you install new systems today, over time you will replace bad ones and they will keep updating new ones. Long time maintainability is an issue with them I think. I’m told i may need to replace all old micro inverters with new ones even though they work. I may be out of pocket a lot. If I had gone traditional I’d have been bette off.
Thanks for the extra detail - this is good information for anyone looking at microinverters. Ideally, you don't want any failures of course, but if you do, depending on how many you have, you could end up in a scenario similar to yourself. I've been in the mobile industry for a long time, and forwards and backwards compatibility are key to building a workable ecosystem. It sounds like Enphase are struggling with this potentially.
All excellent points in favor of using micro-inverters for a grid tied installation. Not so much for use off grid since micros need a "startup signal" to begin converting the output of your solar panel to AC. All of the string type inverters for sale in the US that are UL certified (I don't recall the number) have rapid shutdown capability built in. Thank you for sharing your research!
I haven’t really looked into Offgrid applications, and so appreciate your insight into this. Thanks also for the kind words about my video 👍🏻
They will work fine with AC coupled batteries. I have Enphase micros and a Tesla battery and they will happily start and run on the AC signal provided by the battery.
@@pcw0652 I had forgotten that some batteries essentially have their own inverter built in.
Gary, being totally off grid and dependent on battery power when the sun goes down. How would the batteries now be charged with the panels used this way and how would the batteries be brought into play
So, you can add an AC Coupled battery to any microinverter installation. But in an off-grid scenario, after the sun goes down, your supply will be purely from the batteries - and when they're empty, you lose power. The only option then is to have a fossil-fuel generator on standby, maybe...
Thanks for the video. FYI I had to crank up the volume and it was still hard to hear you. Do you have audio compression set too high?
My pleasure, and sorry for the audio issues - I was using a new microphone but I didn't manage the audio settings properly during editing. Was all sorted with videos coming after that...
Hi, Interesting video. However you seen to completely changed your view. In previous videos your conclusion was sting arrays kept complicated equipment off roof, and doubtful if additional cost of microinverters were worth it in most circumstances. Please clarify your change of heart. Thanks
Hi Laurence, thanks for watching the video, Yeah, you're right - I have warmed up to microinverters, but that's only because I'm spending countless hours researching them, and as I take on board new information, it will surely affect my views on topics (as it should).
What impresses me about Enphase is that they've set out to create products that will operate flawlessly for 25 (and soon 50) years - and they're investing heavily in solid warranties behind them. I'm not seeing the same from the string inverter manufacturers, who can't seem to get past 10 years...
Those who can have ground mount arrays with plenty of room can just add more panels. If I was so crowded that I had to put panels on the roof,I would move. I prefer off-grid so I can fail or survive on my own since I live in Texas. The wood peckers have to keep one eye open in case the rotten poles fall down.
Love it! :-)
Thanks for the video. Question, why SMA stopped there SB240 micro-inverter line ?
You're welcome, and sorry - I don't know the answer to your question. Perhaps someone else on here does...
@GaryDoesSolar The only thing i see is there technology were over passed by the newer solar panels > 250W (10 year ago) vs 400W and more today. The SB240 go only at 240W max. I have a installation with 8 of those ☺