Microinverters - The Future of Home Solar PV?

An in-depth analysis on why I believe inverters are the best solar solution for the mass consumer market.
A great watch after this video is the interview I did with Enphase, talking about their latest microinverter products here: • An Interview with Enph...
Power-line communication:
en.wikipedia.org/wiki/Power-l...
Solar Panel Shading (Part 1): Are Optimisers and Micro inverters Worth It?:
• Solar Panel Shading (P...
Solar Panel Shading (Part 2): More on Optimisers and Micro inverters:
• Solar Panel Shading (P...
Useful article on MLPE (Module Level Power Electronics) and safety:
cdn.ihsmarkit.com/www/pdf/082...
MC Electricals’ optimiser review:
www.mcelectrical.com.au/solar...
Penrith Solar’s Enphase microinverter failure rates (24m30s in):
• “It’s the only thing w...
Anthony Dyer’s KZbin channel:
/ @anthonydyer3939
Anthony Dyer’s optimiser repair video:
• 2022 Solar production ...
Example company providing cost-effective, safe scaffolding solutions:
www.easi-dec.co.uk
Here’s how I calculated the chance of at least one of ten microinverters failing over 25 years:
1. First convert 0.05% chance of a unit failing over 25 years into a probability: 0.0005
2. Then convert this into the probability of a unit surviving over 25 years: 1 - 0.0005 = 0.9995
3. Now work out the chance of all ten microinverters surviving over 25 years: 0.9995 to the power of 10 = 0.995011235
4. Finally, convert this into a chance that at least one microinverter will fail: 1 - 0.995011235 = 0.004988765 (which is roughly a 0.5% or 1 in 200 chance)
Chapters:
0:00 Intro
1:08 Microinverter installation
2:27 Versatility
4:48 System expansion
6:02 Monitoring
7:58 No single point of failure
9:25 Warranties
10:55 Production optimisation: shading
11:55 Production optimisation: dirt
12:33 Production optimisation: panel degradation
13:21 Production optimisation: manufacturing tolerances
13:52 Safety
15:18 Costs
16:19 Technology on the roof
17:03 Failure rates
18:26 Anthony Dyer
20:17 Power clipping
22:03 Mass market installation
25:06 Scaffolding innovation and outro
If you're getting a lot from my videos, and would like to support me in my efforts to help everyone, here are a couple of ways to do this:
1. You could www.buymeacoffee.com/GaryDoes... :-)
2. If you're thinking of switching energy supplier to Octopus Energy. If you call them and give them my referral code ("blue-wind-201") and my name ("Gary Waite") and we'll both get a £50 credit to our accounts as a result! share.octopus.energy/blue-win...
I believe Octopus Energy is doing more than any other energy company in the UK to take us forward to a bright renewable future, and I'll make making reference to them and their initiatives in future videos.
#microinverter #solar #panels
For business enquiries:
Email: [e-mail]
(Please note: despite my channel name, I don't provide, nor consult on, solar installations)
(c) 2023 Gary Does Solar. All rights reserved.
DISCLAIMER
Whilst every effort is made to ensure the accuracy of the content in this video, no warranty for that content is provided, nor should it be implied. Viewers acting on the content, do so at their own risk.

[@terra_incognita683]

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 :)

[@GaryDoesSolar]

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 KZbin 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!

[@PianoImprov.rjgc1991]

Haters are just fools disguised as idiots.

[@markvisser1001]

Hi Gary, After several years of pondering and researching, and many KZbin 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!

[@GaryDoesSolar]

That’s brilliant, Mark. Thanks for your very kind words and I hope all goes well with your setup - it looks a good one! 👍🏻🤣

[@syhartfield]

Excellent content. Makes me proud to be in solar sales woth a company that provides microinverters.

[@GaryDoesSolar]

Thank you. You might also like this video where Enphase let me interview them: kzbin.info/www/bejne/oXimfJSod5yZpKssi=2qYRZ-BYHfiUv0pL

[@steveweatherly1965]

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.

[@GaryDoesSolar]

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.

[@bovnet]

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

[@RoryCJames]

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.

[@GaryDoesSolar]

Hi Rory, good luck with whatever you decide :-)

[@GeoffRichards_GP]

Shout-out for the effort and polish that went into the graphics and animation in this video. Great job!

[@GaryDoesSolar]

Thanks Geoff - yeah, a LOT of hours (they're just PowerPoint animations) but the results are not too bad.

[@GeoffRichards_GP]

@@GaryDoesSolar wow, they look a LOT better than what I would assume a "PowerPoint animation" could produce. They really bring the narrative to life.

[@Just_An_Idea_For_Consideration]

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.

[@GaryDoesSolar]

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...

[@renaulttraficconversion]

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.

[@GaryDoesSolar]

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 🤔 😎

[@derekwhite5090]

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.

[@GaryDoesSolar]

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 :-)

[@TheEnvyc]

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.

[@GaryDoesSolar]

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 :-)

[@loukili63]

@@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.

[@GaryDoesSolar]

@@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.

[@robertblood3722]

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.

[@GaryDoesSolar]

You're most welcome, Bob - and great to hear your solution has been working so well :-)

[@AdamvsMaximvs]

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!

[@GaryDoesSolar]

You’re most welcome, Adam - and good luck with whatever system you choose! 😀💪

[@richardcoughlin8931]

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

[@GaryDoesSolar]

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 👍🏻

[@richardcoughlin8931]

@@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.

[@UK-Expat-in-USA]

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!

[@GaryDoesSolar]

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!

[@153SCORN]

How much more did you end up paying for Enphase over a central inverter. 2 times, 3 times, 4 times, 5 times????

[@viperbite8930]

This is a great site to bounce ideas off of. It is great to talk informatively to the solar companies. Thank you!

[@GaryDoesSolar]

Thanks for the great feedback - really great to hear! :-)

[@adriaan7627]

Again, this is a very thorough and well-explained motivational video to choose a micro-inverter PV system setup.

[@GaryDoesSolar]

Thanks for the great feedback, Adriaan :-) Yeah, I'm really warming up to microinverters!

[@rogertebbutt8586]

Hi Garry...when I was gainfully employed over 20 years ago I developed 12volt wind and solar powered radio communication systems for the emergency services providing two way radio communication coverage of the mountainous areas of Scotland. Unfortunately the preferred location for these repeaters were often nowhere near a convenient public electricity supply. We eventually employed a combination of wind and solar power using DIY kits originally supplied for charging sailing yachts 12v. Battery systems... At the start of the Coved 19 lockdown, I looked into reducing our power usage at home finally purchasing 6 Solar panels and 6 Enphase inverters, plus the Envoy control system, using our holiday savings (as we weren't going anywhere!) Rather than mount the panels on the house roof, I instead built 20 Deg angled Pergola on the side of the house over to the neighbouring fence using 4x2 timbers, spaced exactly one meter apart ( the exact width of one solar panel) four of the solar panels rest upon upon a 2x2 timber picture frame arrangement mounted between each 4x2 beam .. The other two panels are mounted on a tool shed roof located by the side entrance gate, so as to catch the setting sun.... Fortunately we have a clear view over the bungalow next door to the south...ln addition this arrangement also provides a shelter over the side door, and the steps down to the garden and bin store that can often get covered with snow and ice , in addition It provides easy access to the micro inverters and cabling mounted under the panels ...The four panel cables combine with the other two panels in a junction box fitted with a 240v neon lamp. A cable then enters the house through an air brick to a double pole circuit breaker before connecting to the house fuse box under the stairs, plus the Envoy interface... Over the last full year this setup has reduced our electricity bill by over 30% Later I installed a "Solic" divert system to power the original immersion heater in the hot water cylinder providing constant free hot water during the summer.. My next plan is to install two more panels plus inverters ... I can certainly recommend the Enphase system... RT 🌞

[@GaryDoesSolar]

Hi Roger, thank you for taking the time to share your experience with Enphase microinverters here. Wow - sounds like a great system. And being Scottish myself and also an avid hiker, thanks for your work on the emergency systems! :-)

[@SchoolforHackers]

Roger- several great ideas here for my Enphase installation here in far-off New Mexico. Thanks-

[@MikeTsBees]

I was thinking of running panels along my fence line. The power loss from long DC runs is the main reason I haven't.

[@richardcoughlin8931]

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.

[@GaryDoesSolar]

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!

[@axion8788]

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!

[@GaryDoesSolar]

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 😀

[@chadgolden4065]

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.

[@GaryDoesSolar]

Thanks Chad - glad to helped you out in your research :-)

[@physicsparadox10014]

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.

[@GaryDoesSolar]

This is great insight, Christopher - thank you!

[@KoRWraith]

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.

[@GaryDoesSolar]

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?

[@KoRWraith]

@@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.

[@GaryDoesSolar]

@@KoRWraith You could well be right, in a global environment, non-Chinese OEMs need to come up with good strategies to compete!

[@SOLAR-cr5dp]

What about a grid that is off more than it is on? How will essential loads be powered? UPS and batteries?

[@tobiasgoeller6592]

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

[@ToIsleOfView]

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!

[@GaryDoesSolar]

Thanks :-) I try very hard to be objective in every video I make...

[@davidbettney785]

As always...The font of all solar knowledge...Appreciated...Another great video :)

[@GaryDoesSolar]

Thanks David - much appreciated.

[@mikko7296]

"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.

[@GaryDoesSolar]

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.

[@scottmcshannon6821]

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.

[@narrowboatlongpod4176]

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.

[@GaryDoesSolar]

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! :-)

[@randybobandy9828]

But you need soooo many micro inverters and they are expensive

[@WestCoastShredders]

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

[@chrisgauntley8187]

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

[@GaryDoesSolar]

My pleasure, Chris - and great to hear your positive experience with Enphase microinverters :-)

[@user-er9wt4gt1g]

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.

[@GaryDoesSolar]

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 👍🏻

[@vivlloyd2977]

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!

[@GaryDoesSolar]

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...

[@scottkolaya2110]

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.

[@GaryDoesSolar]

That sounds great, Scott! And 36 panels? Wow! :-)

[@scottkolaya2110]

@@GaryDoesSolar Keep in mind, they are 8 years old, so a 280W panel was pretty state of the art then.

[@occamraiser]

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.

[@anthonybowes9273]

Gary, thank for a very informative video, it has given a new insight for our future solar PV installs. Thank you for your time.

[@GaryDoesSolar]

You’re very welcome, Anthony! 😀

[@deletedsmith655]

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!

[@GaryDoesSolar]

Cheers - you might also like this interview I did with Enphase too: kzbin.info/www/bejne/oXimfJSod5yZpKssi=RiYZ0NwX3P1JhOGt There's a lot to be said about Microinverters :-)

[@anthonydyer3939]

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. kzbin.info/www/bejne/eovIimmnatGmmbs 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!

[@GaryDoesSolar]

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.

[@allan4787]

@@GaryDoesSolar MLPE ???

[@GaryDoesSolar]

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

[@chrisangus1964]

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.

[@bertiesworld]

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.

[@battlejohnson9579]

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.

[@GaryDoesSolar]

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).

[@AnnetteDraeger]

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.

[@GaryDoesSolar]

You're most welcome, Annette!

[@George_Philbrook]

Another very descriptive and easy to understand video. Thank you

[@GaryDoesSolar]

You're most welcome, George :-)

[@carlbrown5150]

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.!!🤔

[@ozzieinfrance]

Use an AC battery

[@GaryDoesSolar]

Carl, that’s exactly how a Tesla PowerWall operates.

[@carlbrown5150]

@@GaryDoesSolar That leaves dependance on a grid.!!🤔

[@carlbrown5150]

@@ozzieinfrance Ah Ua yuck Gorsh.!!🤣🤣😂

[@lenwhatever4187]

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).

[@ManfredvonHolstein]

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!

[@GaryDoesSolar]

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.

[@ManfredvonHolstein]

@@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.

[@ManfredvonHolstein]

@@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.

[@GaryDoesSolar]

@@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: kzbin.info/www/bejne/b3jZmXeeeLh9ndE

[@ManfredvonHolstein]

@@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.

[@wanjooalexkim]

Great, concise, and lucid explanation.

[@GaryDoesSolar]

Thank you! Great to hear my videos are coming across well :-)

[@FatTony444]

Very well explained, I like the logical reasoning you use!

[@GaryDoesSolar]

Thanks very much, Tony! That means a lot to me :-)

[@1960ARC]

Why would you want a third party to monitor your private system? People have too much trust.

[@GaryDoesSolar]

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]

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?

[@1960ARC]

@@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.

[@shaunclarke94]

@@1960ARC that would be done on the metering side.

[@robertsmith2956]

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.

[@OldCodeMonkey]

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]

Sounds great, Paul. If I had my time again, I would certainly go for microinverters... :-)

[@dapperdynamicdavid]

@@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.

[@GaryDoesSolar]

@@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.

[@EngineerLewis]

Hi @CodeMonkey69 - what battery did you install if you have one? And is it DC or AC?

[@OldCodeMonkey]

@@EngineerLewis 2 x 8.2kWh GivEnergy with an AC inverter.

[@LukePWilkinsVids]

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

[@GaryDoesSolar]

You’re most welcome, Luke. I’m hoping to release a video interview with Enphase soon too…

[@HaroldJackson]

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.😁

[@GaryDoesSolar]

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: kzbin.info/www/bejne/oXimfJSod5yZpKssi=dDbrA-U_nkKpI-hG

[@mrstock7986]

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.

[@GaryDoesSolar]

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?

[@nickheward4008]

Fantastic video, many thanks for all that excellent information, calmly presented.

[@GaryDoesSolar]

Thanks Nick - very kind of you to say :-)

[@cathodion]

Very good video that deserves much more attention! Thanks.

[@GaryDoesSolar]

Hi Geert - thank for taking the time to comment. I really appreciate the feedback :-)

[@andregrobler4393]

Excellent again Gary. Thnaks for all your research and fantastic presentation!

[@GaryDoesSolar]

It's my pleasure, Andre! :-)

[@funcircle6281]

A great video Gary, thanks for sharing!

[@GaryDoesSolar]

Cheers for the feedback! Very much appreciated :-)

[@Phil-kt6hc]

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...

[@GaryDoesSolar]

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 :-)

[@stephenbrickwood1602]

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.

[@GaryDoesSolar]

Thanks Stephen - totally agree! Glad you liked the video - it took a lot of work, but I'm pleased with the result :-)

[@patricknjau3060]

Hi Gary. Keep up the good work

[@GaryDoesSolar]

Cheers Patrick - thanks for the great feedback! :-)

[@user-ww1ip3ch7l]

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.

[@GaryDoesSolar]

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.

[@waqasahmed939]

@@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

[@pandurangbellary2188]

Very useful video Sir. Pl keep sharing such videos

[@GaryDoesSolar]

Hi Pandurang, thanks for the great feedback. I'll keep the videos coming! :-)

[@TypeRhino]

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

[@GaryDoesSolar]

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! :-)

[@Zirrad1]

If you have an existing inverter/charger could you use the output of the microinverters as the AC charger input?

[@RoKoBa]

Thank you very much for the neutral and unexited fact based presentation. Such videos are of very high value.

[@GaryDoesSolar]

I really appreciate that - thanks for taking the time to comment :-)

[@peterstrous2092]

A fabulous analysis! Well done!

[@GaryDoesSolar]

Thanks Peter!

[@andrisromanovskis9363]

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?

[@GaryDoesSolar]

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...

[@willmorgan6867]

@@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 😅

[@GaryDoesSolar]

@@willmorgan6867 Ah ok, got it - thank you!

[@deang5622]

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.

[@markrainford1219]

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.

[@gregguk100]

Excellent, I'm sold on this.

[@GaryDoesSolar]

Cheers for the feedback, Greg! :-) Microinverters aren't for everyone, but I do believe have an important place in the future of domestic solar.

[@Ian_Woods]

excellent clear and concise video

[@GaryDoesSolar]

Thanks Ian 😀👍🏻

[@bill_heywood]

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

[@GaryDoesSolar]

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): kzbin.info/www/bejne/o6KWf6x_nt-fq5Y - 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).

[@claudiomoles]

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.

[@GaryDoesSolar]

This is great to hear, Claudio! Thanks for sharing :-)

[@ThomKozik]

Fantastic data and information, presented in the most boring way/tone possible. This video is a great cure for insomnia.

[@GaryDoesSolar]

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 👍🏻

[@BackFlippingBaldi2391]

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

[@GaryDoesSolar]

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!

[@thomasjacques5286]

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.

[@GaryDoesSolar]

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!

[@fredwinter2978]

thank you. explained in clear perfect english.

[@GaryDoesSolar]

Thanks Fred - great to hear! :-)

[@Sadowsky46]

Great work, very educational 👍

[@GaryDoesSolar]

Hi Pavel, thank you so much. I'll be making a video on the pros and cons of optimisers shortly too, and will cover the points you raised in your previous comment in those :-)

[@heltengundersen]

well researched and informative.

[@GaryDoesSolar]

Thank you :-)

[@Tensquaremetreworkshop]

'connect them in series' (4:00) - no, you wire them up in parallel. Excellent information, and food for thought.

[@GaryDoesSolar]

You’re right, Mike. AC connections are always parallel. Silly error.

[@Tensquaremetreworkshop]

@@GaryDoesSolar Slip of the tongue- we all do it...

[@chrisandshazza01]

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💪💪

[@GaryDoesSolar]

Haha - thanks Chris :-) And great news about your installation. Hope it goes well!

[@hughmarcus1]

Really interesting ideas there Gary. I note that there’s now several solar installers round here offering systems that are well above (often double) the size permitted for a grid connection on a domestic supply. It seems these systems are generating all their power in DC & using diverters to then direct that power to various loads within the property. Because they never exceed the maximum export load there’s little the network can do about it. Using micro inverters would mean this couldn’t be done I imagine.

[@GaryDoesSolar]

Hi Hugh, yeah, the export constraints are a real issue currently for microinverters, but it needn't be that way. I see no reason why domestic properties cannot generate at whatever level they want, but simply limit the export to levels that the DNO can accept. The Enphase microinverter solution (as an example) is already able to limit the export to the predefined level via the Envoy controller unit, but I don't think (m)any UK DNOs accept that curtailment option. Hopefully, this will change one day...

[@GaryDoesSolar]

Btw, you can do a certain amount of oversizing with microinverters - as each microinverter has a maximum power limit (as described in the video) - so I think you could go for slightly lower powered microinverters to achieve a similar effect as string inverter oversizing...

[@markellse]

So clear. Thanks.

[@GaryDoesSolar]

Great feedback to receive - thank you! :-)

[@bretgreen5314]

Well done; thank you

[@GaryDoesSolar]

Cheers Bret! 😀

[@HowardKlein1958]

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.

[@GaryDoesSolar]

Yeah, that's pretty much the ideal scenario :-)

[@luckyy802]

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.

[@GaryDoesSolar]

Thanks for taking the time to comment - this is great real-world insight - and great that your string inverter is still chugging along :)

[@MrDazthaman]

Solid content pal... Subscribed

[@GaryDoesSolar]

Cheers! Next video coming soon 👍🏻

[@OviMatei]

Best explanation!❤

[@GaryDoesSolar]

Thank you so much! 😊

[@court2379]

This comment section is an endless battle of fighting misinformation and misconceptions. Keep up the good work!

[@GaryDoesSolar]

Haha - thanks! :-)

[@andrewduffin8219]

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.

[@GaryDoesSolar]

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…?

[@andrewduffin8219]

@@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.

[@itautecGmbH]

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.

[@GaryDoesSolar]

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.

[@houstonstarbuck]

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!

[@GaryDoesSolar]

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...

[@TurreTuntematon]

Enphase rules with great quality and also customer service and warranty 😊.

[@GaryDoesSolar]

Yeah, they're showing the rest of the market how things should be done :-)

[@thorstendenk]

Phantastic video! I think now I'm finally convinced completely. Two questions: 1) Can you tell about how Enphase compares to APSystems? 2) Exists something equivalent for batteries? Thanks a lot! Thorsten from Spain.

[@GaryDoesSolar]

Thanks Thorsten :-) Now, I don't know anything about APSystems unfortunately, so can't comment. I may do a video on batteries in the future...

[@evinvestfuture7440]

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.

[@GaryDoesSolar]

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...

[@marioreznik3654]

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.

[@GaryDoesSolar]

You're most welcome re. the video - and I know what you mean about answers and more questions resulting!

[@asifalikhan8189]

Thanks..very good Content

[@GaryDoesSolar]

You're most welcome - thanks for the great feedback!

[@bazcurtis178]

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 KZbin 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.

[@GaryDoesSolar]

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! :-)

[@nightowl1on1]

Great content thanks for sharing. Subbed and liked :)

[@GaryDoesSolar]

That's fantastic - thank you very much! :-)

[@q.e.d.9112]

It occurs to me that, for new builds or re-roofs, it might be a good idea to have a glazed roof over your solar system. This would give access to the underside of the solar panels via the loft space, and provide weather protection for all the electronics. I guess there would be a small decrease in insolation. It would also make it easier to capture the thermal energy dissipated by the solar panels.

[@GaryDoesSolar]

Yeah, this could be a good solution - I'm not a roofing expert, but perhaps others can comment as to the viability of this...

[@julesvreug]

I had this option 8 years ago back then it seemed like a good option as expandable etc, each controler could be seen by an app/web to diagnose faults and could be isolated. but the cost back then was slightly higher than what i could afford + i expected reliability issues as behind a solar panel gets extremly hot and heat + inverter dont go well. These days prob improved a lot.

[@GaryDoesSolar]

Yeah, I've seen lots of improvements with microinverters over the years, including reliability (50 year lifetimes on the horizon)...

[@michiganengineer8621]

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!

[@GaryDoesSolar]

I haven’t really looked into Offgrid applications, and so appreciate your insight into this. Thanks also for the kind words about my video 👍🏻

[@pcw0652]

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.

[@michiganengineer8621]

@@pcw0652 I had forgotten that some batteries essentially have their own inverter built in.

[@tonyv1505]

Informative thank you

[@GaryDoesSolar]

Cheers Tony - thanks for watching!

[@peternorman2563]

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.

[@GaryDoesSolar]

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.

[@valeriomarchioni8617]

Thank you a very good video!!!

[@GaryDoesSolar]

You are welcome! 😀

[@sleekitwan]

Well theoretically at least, the higher the voltage and the sooner you get it into AC form, the better the transmission and you have lower transmission losses. That is solid theory. You are well aware I am sure, that cabling to and around a home, can be a lot more than we imagine. I think especially if the mounting point is say an outhouse, this is a good way to go. I know not much about this stuff, but have a great deal of interest in getting something going at a price we can afford ie not much. Bear in mind, there’s an awful lot of interest in motor vehicles going AC for reasons of losses too I think? But also Bluetooth and zero wire methods of course are being considered there. Works for signal strength power, can’t work for power circuits of course, that’s going to be chunky cable all day. I think this has massive merit, very interesting, thanks. PS I do have an amount of education in electrical engineering, and have had friends in the power business, so that’s how I know anything at all about it.

[@GaryDoesSolar]

Yup, AC certainly has benefits over DC, as you describe well.

[@deang5622]

AC isn't lower loss. It's the fact you can step up an AC voltage to a higher AC voltage using a simple transformer and the transformer will step down the current. The losses are a function of the current and not to do with whether it is AC or DC.

[@slimanus8m]

Great video, I wish there was a section on the integration with batteries and chargers and how does it work and perform

[@GaryDoesSolar]

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.

[@DJWHITE_]

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]

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 :-)

[@DJWHITE_]

@@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!

[@kevingovender1957]

+1 sub for simple explanation and animation

[@GaryDoesSolar]

Hi Kevin, that's really kind of you - thanks! :-)

[@kevingovender1957]

@@GaryDoesSolar Can you please do a video about voltages(12v, 24v, 48v) as i dont understand why the difference. I see videos on the net but i thing you would explain it better.

[@GaryDoesSolar]

@@kevingovender1957 I've got a backlog of about 30 video topics I'd like to cover and so will add this to the list. I generally choose the next video topic based on what I think will be the most popular 👍

[@pmbpmb5416]

Again another very useful video for the average idiot like me . This one has made me think given the now low cost of panels that I will ask to cover all available roof space including some shaded north facing , accepting generation on some will be low but it will add to the overall total at relatively little cost .

[@GaryDoesSolar]

Thanks - glad the video was helpful to you! Your approach is sound to me - and one with minimal regret, I'd argue. Good luck with everything! :-)

[@petercallewaert4492]

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.

[@GaryDoesSolar]

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.

[@petercallewaert4492]

@@GaryDoesSolar Thank you Gary.