First Enphase Microinverter Issue? - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: March 07, 2025, 02:32:45 am
content: Got my first reported Enphase microinverter issue today.I'll wait a day and see if it clears itself.

author: EEVblog
author_rank: Unknown
timestamp: March 07, 2025, 03:21:45 am
content: Looks like it died on Feb 26th?

author: bdunham7
author_rank: Super Contributor
timestamp: March 07, 2025, 04:44:33 am
content: Does your gateway have a separate energy measuring function? My (update) one has a current transformer and it can give me generation and power measurements without relying on the microinverters. Sometimes the microinverters can (and will) keep on producing energy even when they aren't reporting or in communication with the gateway. IDK if the newer ones or the ones in your market are allowed to do this, but mine are--they produced power out of the box with no internet. In any case, some evening after the sun goes down you can look at your total energy produced for the day and compare the result from the gateway CT and the sum of the results from the micros. If there's an additonal micro worth of production, then you know it is still working and just not reporting.IDK if this applies to your units, so YMMV.I've lost two micros out of 30 now in 12+ years. Both had AC voltage measurement issues.

author: EEVblog
author_rank: Unknown
timestamp: March 07, 2025, 06:49:38 am
content: Quote from: bdunham7 on March 07, 2025, 04:44:33 amNo.But I have other monitoring systems, but that's combined over two system, so will be impossible to tell.

author: Stray Electron
author_rank: Super Contributor
timestamp: March 07, 2025, 02:45:14 pm
content: Quote from: EEVblog on March 07, 2025, 03:21:45 amAre those waveforms that are shown on the 23rd, 24th and 25th normal? Is it normal for those inverters to have such different waveforms in general? What does the waveform from a working inverter look like?

author: johansen
author_rank: Super Contributor
timestamp: March 07, 2025, 07:15:49 pm
content: Quote from: Stray Electron on March 07, 2025, 02:45:14 pmMy guess is cloud cover could produce what's on the 23rd, but it's too symmetrical for that. The 25th looks like it cut out completely for an hour or two.Looks like it worked briefly on the 26th for an hour, and the graph is not accurate, there should be no line connecting the 26th to the 28th.So not only do you have an inverter failure but you have a software reporting/housekeeping failure too.no hardware failure that i can think of, would cause the software to report continuous, non existant, but continuously decreasing energy production starting at 40 watts and decreasing to 25 watts linearly over 48 hours.

author: bdunham7
author_rank: Super Contributor
timestamp: March 07, 2025, 07:28:46 pm
content: Quote from: Stray Electron on March 07, 2025, 02:45:14 pmNothing terribly unusual about those although you'd want to compare them to a full-system graph. Here's my system for the past 7 days. We've had some rainy days.

author: floobydust
author_rank: Super Contributor
timestamp: March 07, 2025, 08:06:15 pm
content: Dave do you ever reboot things, like a grid disconnect done at night should pull power to the microinverters?I would expect the MCU/wireless to have power and respond, even if the power electronics has bagged - unless it's a blown fuse.NSW historical weather charts it wasn't that hot out ~24°C I think... or did it rain. Hmmm.

author: bdunham7
author_rank: Super Contributor
timestamp: March 07, 2025, 08:44:51 pm
content: Quote from: floobydust on March 07, 2025, 08:06:15 pmIDK for sure about the later models Dave has, but my Enphase inverters appear not to pull power from the mains at all (other than to measure) and are powered only from the DC side. If the sun goes down or the solar panels disconnect, they stop communicating entirely.

author: John B
author_rank: Frequent Contributor
timestamp: March 08, 2025, 02:11:17 am
content: I would like to hear more about Dave's comment that the warranty on the units is contingent on them being connected to the internet - and therefore being subject to data harvesting.I would 100% be writing to the ACCC if the company decided to pull any shenanigans like that.It's an angle that I hadn't thought about, but it's almost certainly the next evolution in "how you're getting effed this week", and the subject of an upcoming Louis Rossman video.

author: EEVblog
author_rank: Unknown
timestamp: March 08, 2025, 03:32:22 am
content: Quote from: John B on March 08, 2025, 02:11:17 amThey seems to be implying it:https://enphase.com/en-au/download/enphase-energy-limited-warranty-australia-2019?srsltid=AfmBOoqjAJfQGT7FryQDsDUjnSmdihZLm5j0Pe4-88xH-inngBM9DNNN

author: bdunham7
author_rank: Super Contributor
timestamp: March 08, 2025, 04:21:27 am
content: Quote from: John B on March 08, 2025, 02:11:17 amIDK what data they would harvest that would be of any interest other than to them and their customers. Theirextended10-year warranty appears to be expressly conditioned on them being connected, which sort of surprises me because there's no exception for remote installations without internet. But I do see why they would want to do this and it isn't to sell your data, it is to verify that the inverter is being used in it's original installed location (a long-time requirement that applies to mine as well) and that its operating parameters aren't being exceeded.In addition, the monitoring service that they provide as well as the warranty process itself is facilitated by the connection. I've had two fail, each time I got an email and when I went to check it in Enlighten, there was a button or link to start a warranty claim. You click through, it sends the data to a service tech that decides whether to just replace it or to investigate further. One time they just sent me a new one and the other the guy sent me an email with a few questions and then sent the replacement. You plug it in, go back to Enlighten and enable it and you're back in business. And that's another thing--I think the new ones won't even activate until they are enabled. They automatically assign the orginal warranty to the new unit and that's that.IDK what the alternative would be or how it could be easier. With my gateway and inverters, I would have the option of local access with their app even without internet. That's how you configure the system initially and you can access it that way later. But it doesn't have all the features of Enlighten on their server and of course, no warranty self service.

author: EEVblog
author_rank: Unknown
timestamp: March 08, 2025, 06:30:59 am
content: Quote from: bdunham7 on March 08, 2025, 04:21:27 amI didn't see that, I'll take another look, thanks.

author: Stray Electron
author_rank: Super Contributor
timestamp: March 08, 2025, 03:38:11 pm
content: Quote from: John B on March 08, 2025, 02:11:17 amOh, it's worse than that. I looked into buying a system a few years ago that used Enphase inverters and the salesman just happened to mention that the finance company can shut your inverters off by remote control if you don't make your payment on time. I asked what would happen if I disconnected the inverters from the net and that they would timeout and shut off. I looked up the installation manual for the model that they were selling and sure enough it does tell how the installer can set up a master password and control the inverter over the internet.I could never get a straight story from the seller but they don't do the installation and I think that they are only a finance company and they want to sell systems and hold the mortgage on them. They do warranty the systems (so they say) but they have someone else do the repairs and it couldn't tell me anything about who that was or anything else. As far as I was concerned there were just too many unanswered questions so I dropped the whole idea. In addition, I've seen TOO many cases where companies go out of business or simply decide to "no longer support that model" so the owner is SOL so I will not buy anything that can be controlled over the net or that anyone other than myself has complete and total control over.I wanted a system that I could buy outright and that has complete control over but they don't seem to sell those anywhere in my part of the state. All of the companies that I talked to want you to either finance (or lease?) systems and they seem to have no provision to simply sell them. The nearest company that I could find that sold systems outright and that didn't play games was in Texas.

author: watchmaker
author_rank: Unknown
timestamp: March 11, 2025, 12:49:23 pm
content: Quote from: bdunham7 on March 08, 2025, 04:21:27 amI agree (at least this is my understanding of what I read).We had Revision install our 6KWH system here in New Hampshire and it was no more difficult to buy it outright than financing it. Probably less so.I did not want to deal with an independent installer who like many contractors go out of business just as warranty claims start coming in. About 10% more; but they are an employee owned multistate corporation used for virtually all large installations.At least we got it (and our heat pump water heater) in time to collect our tax credits and rebates. For the last week (February in NH!) we have collected over 36KWH per day. And NO delivery charge which was over 1/2 our bill.

author: Geoff-AU
author_rank: Frequent Contributor
timestamp: March 14, 2025, 12:47:43 am
content: Quote from: Stray Electron on March 08, 2025, 03:38:11 pmSo much nope. Part of my reason for installing PV is the self-sufficiency/resiliency aspect and it absolutely needs to run without the internet.My inverters are blocked at the router. I run my own monitoring and do firmware updates as required (never, unless there's a problem).

author: floobydust
author_rank: Super Contributor
timestamp: March 14, 2025, 01:14:19 am
content: I think inverter manufacturers need to be able to remotely update their firmware. For any bugs, heating issues etc. so it can live long. This assumes the product is not well tested or refined though. I understand the need to have them connected to the hive but not controlled by others. Do you actually own these or are they licensed to you?And, they are potted, non-repairable, disposable really located in the worst possible place for electronics - roof for heat, moisture as well as being inaccessible. ICK.I'd have to do some math to see if microinverters are really worth it - selling for around $0.50/watt here. For the extra energy generated, that payoff - replacing them is costly and won't be done in winter here, reliability is expected to be poor, and this Internet-access dependency is a final deal breaker.

author: Geoff-AU
author_rank: Frequent Contributor
timestamp: March 14, 2025, 05:12:50 am
content: Quote from: floobydust on March 14, 2025, 01:14:19 amIf it can damage the product then it has probably already damaged the product. This is a recall proposition not a sneaky patch from the cloud that the customer has no visibility of. I'm not paying an inverter company to use my installation as part of their beta testing.QuoteFor simple installations, they definitely aren't worth it. The maths and comparisons have already been done.

author: EEVblog
author_rank: Unknown
timestamp: March 14, 2025, 06:58:16 am
content: Coincidentally my Envoy just failed to communicate today at 1:30am and lasted until I reset the power to the Wifi router. Repowering the Envoy did nothing.Hadn't touched anything, so presumably just a WiFi'y connection glitch.

author: EEVblog
author_rank: Unknown
timestamp: March 14, 2025, 07:01:00 am
content: Quote from: Geoff-AU on March 14, 2025, 05:12:50 amI did the math when I was expanding my system. Go with an 100% expanded Enphase system, or go with the string Hybrid Deye.It was no contest, the Enphase was WAY more expensive and locked me into an insanely expensive Enphase battery solution.I only have the Enphase system because they gave me the system for free (minus cables and install).

author: EEVblog
author_rank: Unknown
timestamp: March 14, 2025, 10:48:21 pm
content: The Enphase Envoy S has failed AGAIN:

author: nctnico
author_rank: Super Contributor
timestamp: March 15, 2025, 10:34:42 am
content: Quote from: Geoff-AU on March 14, 2025, 05:12:50 amThe micro inverters aren't worth it -period- both financially and from a maintanance point of view. As a rule of thumb you have to keep installations simple and put potential failure points in an accessible area. This means having as little as possible on the roof and put the inverter at a place you can work on it. Another problem specifically with Enphase is that the system consists of many different (kinds) modules and each one adds another point of failure.Where it comes to solar installs: extra money you invest, extends the ROI period so keeping a solar install cheap is key. Don't spend extra on more expensive inverters, monitoring systems and so on. With government subsidies / feed-in tariffs changing faster than fashion styles, there might not even be an ROI in the long run. IMHO a good rule of thumb is don't install solar unless the ROI period is less than 5 years.

author: Zucca
author_rank: Unknown
timestamp: March 15, 2025, 09:02:29 pm
content: This.Power electronic cooking on the roof is never a good idea.It would maybe make sense in partial shading condition, but uinverters will be always a unfortunate plan B in my book.

author: floobydust
author_rank: Super Contributor
timestamp: March 16, 2025, 02:28:16 am
content: Dave, it appears Enphase Envoy S red blinking LED's it's stuck in boot and bricked. I looked on other forums and they say get an RMA and send it back. Usually 2 minutes for it to boot up.It really must be frustrating, I would be upset. The gateway sells for over $1,000 here and I'd expect better reliability.The question is who pays for this repair? The unit's config hopefully is saved in their cloud? but it's emails etc. to Enphase and the installer - do they take the labour cost hit replacing this? The microinverters keep working or do they shut down over no Internet access, and assume you haven't paid your invoice lol. This whole thing can get really silly...

author: EEVblog
author_rank: Unknown
timestamp: March 16, 2025, 09:05:08 am
content: Quote from: floobydust on March 16, 2025, 02:28:16 amIt's not bricked, it works again.

author: tszaboo
author_rank: Super Contributor
timestamp: March 16, 2025, 12:39:33 pm
content: Quote from: nctnico on March 15, 2025, 10:34:42 amActually over the years it's been changing what panel + inverter combinations are the best value.I think those 4 input microinverters (from hoymilles for example) might very well be in the financial sweet spot right now.Take a look at this:https://www.solar-bouwmarkt.nl/hms-1000-micro-omvormer-1-fase-copy.htmlThis gives you MPPT per 2 panels, 2KW capacity, at 125EUR/KW. I invite you to find better value inverters.

author: nctnico
author_rank: Super Contributor
timestamp: March 16, 2025, 01:43:33 pm
content: Growatt 4.2kW for 499 euro:https://www.stralendgroen.nl/product/growatt-min-4200tl-xh-hybride/?v=1a13105b7e4eThis has support for battery storage and it doesn't need a gateway for commissioning.

author: Siwastaja
author_rank: Super Contributor
timestamp: March 16, 2025, 01:51:35 pm
content: Microinverters have some theoretical potential but it's a really difficult set of engineering constraints to work with. You need to do a higher reliability product working in more demanding ambient conditions, develop additional wireless or PLC communication systems, and doall thatvery cheaply; your process of design and manufacturing needs to be more competitive than the cheap Chinese string inverters. Nearly a miracle is needed to achieve that. The equation is not fundamentally impossible by any law of physics, but it sure is difficult to achieve. And if you manage to succeed in all that, what do you have? Still basically a product which does the same as the competition, turns light into power.The simplicity and low cost of adding battery connection to the common DC bus of a centralized string inverter was the final nail in the coffin of microinverters. Because that adds onesignificantextra feature over that "turn light into power" marketing equation. Having something like that would be exactly what microinverters would need to become marketable, but sadly for them, this killer feature entered the competing (and already winning) camp.Batteries usually make no financial sense, but it turns out they are very much marketable; people want to buy them. It makes a huge difference if a battery feature in the inverter system costs $200 or $2000 more.

author: tszaboo
author_rank: Super Contributor
timestamp: March 16, 2025, 02:39:42 pm
content: Quote from: nctnico on March 16, 2025, 01:43:33 pmOnce you add DC disconnect switches for this, they are ballpark the same price, and the microinverter will make more power from the same sunlight.I am almost never considering battery storage, as all these inverters only support overpriced batteries.We are in agreement about the Enphase inverters, they are never worth it, unless you get them for free.

author: Siwastaja
author_rank: Super Contributor
timestamp: March 16, 2025, 02:46:54 pm
content: Quote from: tszaboo on March 16, 2025, 02:39:42 pmGrowatt obviously has internal DC disconnect switch like every other string inverter.QuoteNot true at all. In fully lit conditions, microinverters produce 1-2% less due to their worse efficiency. Partial shading needs to be continuous and pretty bad for this net loss to become significantly positive; in which case absolute production is still crap; it makes little sense to install PVat allin shaded locations.

author: nctnico
author_rank: Super Contributor
timestamp: March 16, 2025, 03:47:14 pm
content: I really don't see how a microinverter can get more power from a solar panel compared to a string inverter assuming both have the same power rating. Looking at the Enphase micro inverters, they typically don't support maximum output from a modern 400Wp solar panel. Looking at the Hoymiles inverter I have doubts about its 2kW capacity. Maybe it can do that on a cold day but underneath a hot solar panel on a hot day, something has got to give. At 2kW the Hoymiles 2000t inverter dissipates 90W. How is that going to work in such a small housing? The Growatt inverter (to be mounted indoors or in the shade) has a huge heatsink at the back despite having better efficiency compared to the Hoymiles.

author: floobydust
author_rank: Super Contributor
timestamp: March 16, 2025, 04:41:19 pm
content: Quote from: EEVblog on March 16, 2025, 09:05:08 amHow long was is acting up for? From the video is looked like quite some time, many hours. I guess they have elves working in the background.Many search engine hits for the problem came up on other forums.Hoping these are reliable because nobody includes repair costs, labour etc. in their solar calculations. It's all unicorns and rainbows where the gear works great for 10+ years.

author: bdunham7
author_rank: Super Contributor
timestamp: March 16, 2025, 04:50:08 pm
content: Quote from: floobydust on March 16, 2025, 04:41:19 pmWhen I installed my system many solar suppliers were including a mid-life inverter replacement in their calculations as the string inverters at the time had widespread reliability issues. Enphase provided a 25 year warranty.

author: bdunham7
author_rank: Super Contributor
timestamp: March 16, 2025, 04:55:35 pm
content: Quote from: nctnico on March 15, 2025, 10:34:42 amI'll agree with that part, but the rest of it is totally YMMV according to your location, regulations, circumstances and luck. My particular Enphase system has paid for itself 2X and is still functioning 12 years in. I did upgrade the gateway and have replaced 2 inverters (warranteed) but even if I had done absolutely nothing the system would still be working and producing 93% of its original power. There are almost no failure points that would cause it to stop working entirely, only a failure of the mains electrical connection could do that. Again, YMMV and I understand that not all systems share the same characteristics.

author: tszaboo
author_rank: Super Contributor
timestamp: March 16, 2025, 11:36:17 pm
content: Quote from: nctnico on March 16, 2025, 03:47:14 pmYes yes, enphase is bad, doesn't even max out a panel. We know it.Try making energy out of this, without DC optimizers, or making a hole on the neighbor's roof.This is a snapshot of my system a few days ago. The lower panels made 1MWh-1.1MWh each, the uppers 1.3MWh over their lifetime.

author: EEVblog
author_rank: Unknown
timestamp: March 17, 2025, 02:21:16 am
content: Quote from: bdunham7 on March 16, 2025, 04:55:35 pmThat's the point of a microinverter system, you essentially have a bunch of redundant systems.I currently have 1 microinverter down but I don't even notice it across 14 independent systems.My Envoy went offline for a bit, but the microinverter just kept doing their thing, the envoy is only needed for monitoring and firmware updates.If my Deye string inverter goes down, I know it, because I lose both strings, the whole thing goes down.

author: EEVblog
author_rank: Unknown
timestamp: March 17, 2025, 02:23:25 am
content: Quote from: nctnico on March 16, 2025, 03:47:14 pmBecause individual solar panels can have different outputs (shade, clouds, dirt, poop etc). The microinverter will MPPT each panel individually rather then have one or two MPPT's per string.

author: EEVblog
author_rank: Unknown
timestamp: March 17, 2025, 02:25:34 am
content: Quote from: tszaboo on March 16, 2025, 02:39:42 pmMy Deye can work with any battery, even lead acid.

author: uer166
author_rank: Super Contributor
timestamp: March 17, 2025, 04:37:17 am
content: Quote from: EEVblog on March 17, 2025, 02:23:25 amA string inverter will practically find the global peak that won't be much different than MPPT at the panel level. The bypass diodes will forward bias the severely shaded sections of the panels, usually with 2 or 4 subsections per panel.

author: Siwastaja
author_rank: Super Contributor
timestamp: March 17, 2025, 09:03:12 am
content: Quote from: tszaboo on March 16, 2025, 11:36:17 pmDoesn't look too bad. The more shaded group made 1.05/1.3 = 80% of the unshaded group. Yet the shaded power is like 40W/160W = 25% of unshaded power (which sounds typical). Therefore we can estimate that shading time is 25/80 = 31% or so. From this, we can roughly estimate the average production:Microinverter system = 7 * 160W + 4 * (0.69*160W + 0.31*40W) = 1611WString inverter system = 7 * 160W + 4 * (0.69*160W + 0.31*0W) = 1562WReality can be of course more complex than this but this is the ballpark. You need a seriously more shaded system for the difference to grow. Like, if you said you had one panel produce 1.3MWh total and all others being in 0.5 - 1 MWh range, then I would buy the claim it makes a difference.The point people intuitively miss is that the "advantage" of gettingsomepower out of shaded panels is not very big because, well, there is no much power to be had when there is not much light! And partial shadowing of a single cell destroys the production of that series string of cells (a segment, 1/3 of a panel) regardless of the inverter type. So really the difference is, is a partially shaded panel able to produce 0% or 25% of full power. Not a big difference because 25% is not a lot to be had."Extra production" of microinverters/optimizers fall apart nearly every time when calculations or testing is being done. The gain could be in range of 15-20% in absolute best case. Then again the loss from worse efficiency, worse peak current rating, and thermal throttling is in the same 15-20% range in absolute worst case. And in typical cases, microinverters produce the same as string inverters, maybe +/- 5%, differences lost in noise.And what comes to those ~100W panels, they don't go to zero with string inverter. They are likely producing half to 2/3 of full rated power because some of their segments are shaded and producing nothing, with bypass diodes activated, and others segments producing fully. NOTE: these segments produce nothing even with a microinverter! You would need a microinverterfor every segmentto see this in numbers. Here, microinverters suffer exactly the same fate as string inverters, because really, all microinverter is: it's a string inverter for e.g. 60 series cells with 3 bypass diodes over each 20 cells. Compare this to string inverter, which fundamentally is, for example, 600 series cells with 30 bypass diodes.tldr: I believe those 11 panels fall in three groups:Unshaded - same production with string vs. microinverterEvery segment shaded - string inverter produces 0 for the whole panel, microinverter producessomethingAt least one segment unshaded - same production with string vs. microinverter

author: Jeroen3
author_rank: Super Contributor
timestamp: March 17, 2025, 09:57:39 am
content: Quote from: EEVblog on March 17, 2025, 02:23:25 amThis will not give you much more benefit unless your array is very poorly shaded.Enphase only has an advantage against poorly configured strings where the boost mode of the inverters can do some power vs the string not doing any because the voltage is too low. You don't have to sugarcoat the system because you payed a lot. There are barely any economical benefits for enphase. Just be honest to yourself.I got enphase because I didn't want the coil whine of a dc/ac inverter indoors.Only thing left is safety: any idiot can wire an enphase system without risk of fire. Which is vastly different for traditional string systems which require though and care when installing. Which if often missing with installers.However, compared to the similar (priced) system from solaredge, enphase is much more reliable.I had one iq7 fail like yours, it recovered after an AC power cycle.The envoy can fail, it's a computer. Yours is outside, I believe it's conformal coated, but even that is not perfect.-offtopicMaybe you can try one of those new Victron Multi RS hybrid units, they are much more versatile and better supported and documented than deye and growatt. I've seen reports of people with deye's that don't turn off when a cell falls out due to imbalance. Which is really dangerous.

author: tszaboo
author_rank: Super Contributor
timestamp: March 17, 2025, 12:47:14 pm
content: Quote from: EEVblog on March 17, 2025, 02:25:34 amThat's quite good, I wish more manufacturers would do that.There are quite some battery chemistry and packs available now, and by the looks of it the later someone buys a pack, the lowest KWh/money they can get. So an existing inverter only supporting packs that are designed years ago is not optimal at all.I would like to see more AC coupled systems, that support many different type of batteries.Quote from: uer166 on March 17, 2025, 04:37:17 amBut you see, the situation is not that clear. If you have a roof without obstructions, optimal orientation, then yes a string inverter will work optimally. If you have a roof like mine, and panels will have varying amount of shading, it's very different. Especially that a microinverter/optimizer equipped system will generate more energy in the early morning and evening. The sun is at a lower elevation, more objects will have a chance to make shading. You can just throw out that generation with that bypass diode, or harvest that extra 10% of that panel if you have MPPT per panel. If there is partial shading on 4-5 panels, like the example that I gave you, suddenly those numbers add up, and the story is very different.If you just look at the KWh generated, it also doesn't tell the whole story. That few % extra generation happens at times that you are actually home, increasing self-consumption, even without a battery.There just isn't a one size fits all solution.

author: Siwastaja
author_rank: Super Contributor
timestamp: March 17, 2025, 04:27:07 pm
content: Quote from: tszaboo on March 17, 2025, 12:47:14 pmMaybe, maybe not.If you partially shade 5 panels such that 1 diode-bypassed segment gets blocked, which is pretty usual from sharp edges like power line shadows, chimneys, etc., then the lit segments provide the power, and the blocked segment get its bypass diode activated and produces nothing.No difference between string inverter and microinverter. Microinverter's MPPT finds the point where e.g. 2/3 of the panel produces all power, and 1/3 is bypassed by the diode. String inverter's MPPT does the same.Situation where microinverter provides any advantage is blockage of most of the panel (e.g. 2/3 or 3/4 of the segments); or soft shadow over the whole panel. In such case, microinverter's MPPT will find different power point than string inverter's one, and produce non-zero output.But the most productive "partial shading" situation is the one where 2/3 (or 3/4) of the panel is producing fully. And this is well handled by both string and microinverters, by the exact same mechanism - bypass diodes. With both inverter types, you will then lose the the production of the blocked segment. To have that, you would need a microinverter connected to the center taps of the panel junction box; in other words, 20-cell modules instead of 60-cell modules.

author: uer166
author_rank: Super Contributor
timestamp: March 18, 2025, 12:38:27 am
content: The only real benefit here would be if the panels are pointed towards different directions on a roof and get consistently different illumination.

author: nctnico
author_rank: Super Contributor
timestamp: March 18, 2025, 10:27:56 am
content: Quote from: uer166 on March 18, 2025, 12:38:27 amYes, but in such a case you can use a string inverter with multiple MPPTs. Ofcourse you can try to fill every nook & cranny of an odd shaped roof but you'll hit the point of diminishing results quickly. ROI should be the key driver, not maximum production.

author: Siwastaja
author_rank: Super Contributor
timestamp: March 18, 2025, 11:04:44 am
content: Yeah, typical string inverter of today handles most L shaped roofs. For more complex shapes, the question to ask is, does it make sense to add panels beyond the two most obvious directions (e.g. in L shape), to a third or fourth direction? How many panels would fit, compared to the low hanging fruits? Would they be partially shaded or in unoptimum directions (e.g. North (or South in Australia))?It is quite rare to have a roof with three or more directions which all produce well. Even then, nothing prevents combining string and microinverters. Just normal string inverter for the two main circuits and for those odd few outlier panels a 2- or 4-input micro or two.Emotional reasons should not be ignored, someone might enjoy the idea of their weird/unoptimum roof producingsomething, and the value of being able to accurately monitor how each spot behaves.

author: EEVblog
author_rank: Unknown
timestamp: March 18, 2025, 11:31:07 am
content: Quote from: Siwastaja on March 18, 2025, 11:04:44 amYes, if I had an oddball roof like that I'd want microinverters to get the most out of it and also to see how each one performs individually.

author: David_AVD
author_rank: Super Contributor
timestamp: March 18, 2025, 09:54:24 pm
content: At home I have 24 x 415W panels (9.9kW) spread over 3 aspects (8 East, 7 North, 9 West) with an 8.25kW string inverter.The system works well, giving me a slightly lower peak output but more output at each end of the day that a single North aspect would have.

author: fastbike
author_rank: Regular Contributor
timestamp: March 19, 2025, 01:00:00 am
content: Quote from: tszaboo on March 16, 2025, 02:39:42 pmThe world is changing reasonably quickly, and becoming flooded with used EV batteries which can be repurposed for BESS, thus avoiding lock in to expensive proprietary batteries.E.g.https://github.com/dalathegreat/Battery-Emulator/wiki

author: Siwastaja
author_rank: Super Contributor
timestamp: March 19, 2025, 06:39:46 am
content: Quote from: fastbike on March 19, 2025, 01:00:00 amAs always, there is a massive gap in price between DIY and turn-key solutions, it's no news.Say you want a 10kWh battery storage system. So do you:* Buy hybrid inverter + battery as turn-key, costing you 13000€,* Buy the same stuff yourself and just hire an electrician to do the job legally with hourly contract, costing you maybe 5000€* Buy the same stuff yourself and illegally install it (or legally if you happen to be a sparky), costing you maybe 4000€* Find second-hand EV battery and build necessary electronics yourself, and get a 20 or 30 kWh battery instead for maybe just 2000-3000€First case is hard to ever make pay for itself, even if you combine all possible sorts of spot price, PV buffer, frequency containment reserve market, peak power shavings and whatever multimarket optimizations you can find. Last case pays for itself possibly even just for PV buffer + some simplistic spot price algorithm alone.The sad fact that we tinkerers seem to forget is that 99.9% of population are neither capable or willing to tinker (possibly illegal and dangerous stuff; heck, just commencing a home router is too much for many!) So in the big picture, turn-key solutions dominate, whatever their cost, and us tinkerers getting the same quality-of-life for fraction of cost is an exception to the rule.

author: tszaboo
author_rank: Super Contributor
timestamp: March 19, 2025, 09:38:50 am
content: Quote from: fastbike on March 19, 2025, 01:00:00 amOn one hand I'm in theory an advocate for second life car batteries. On the other hand, you see that most car battery packs are weirdly shaped, and too large for in-home usage. Difficult to move without a forklift. Voltage of the pack is too large for typical inverters. With the exception of VW battery packs. They are ~48V and 32 kg, and look like a brick.And from what I can see, off the shelf battery packs are often cheaper than these second life batteries, when you include BMS, cabling and all the other things you need to make them work. And then we'll have sodium batteries in no time, I expect them to be significantly cheaper than lithium.

author: Siwastaja
author_rank: Super Contributor
timestamp: March 19, 2025, 10:31:43 am
content: Quote from: tszaboo on March 19, 2025, 09:38:50 amYou are looking at wrong "typical" inverters. SELV inverters are dead; good riddance. Well they are fine for light duty or hobby use, or low-power off-grid, but for true home batteries, non-isolated, high voltage topology is obvious. It has significantly better efficiency and lower cost, and can supply much more power without requiring ridiculous wire gauges.Look at any usual hybrid inverter brand. Like Kostal, Growatt, Sofar, Sungrow, Solis, Deye, Huawei, and so on and so on. All have HV battery options. They operate in the shared internal DC bus with the solar MPPT trackers (basically the battery is just one more "MPPT tracker"), which makes the architecture cheap and flexible (i.e., the voltage range is as large as the PV voltage range is, enabling flexible number of series battery modules). Coincidentally, from voltage perspective these are also compatible with almost any second-hand EV battery; all that is needed is a BMS translator (working as a bridge between the EV manufacturer's BMS protocol and the inverter's different BMS protocol).I agree though that the packs have an awkward shape. It is obvious why home batteries are "towers". Second-hand EV battery takes a lot of floor space and a forklift is indeed needed to get it in.

author: nctnico
author_rank: Super Contributor
timestamp: March 19, 2025, 11:06:54 am
content: IMHO using old EV batteries for home storage batteries is a poorly conceived idea.1) It is much better to use those batteries to keep existing EVs going. Sensible car manufacturers use modular battery packs which can be repaired partially. Good battery cells / modules have a much higher value on the used car parts market than to make home batteries from. What is leftover is just scrap.2) As a home battery manufacturer it is much easier to work with a consistent and predictable influx of components than dealing with (what basically is) unknown scrap. Customers will want a warranty after all. How to provide that on used parts? At the end the price is just as high when using new cells. One (example) issue is to properly match cells that go into a pack and have the BMS tuned for the specific chemistry. In the past I have done some work (manufacturing systems and BMS development) for a Li-ion battery manufacturer and they even find rejects among brand new cells.

author: Zucca
author_rank: Unknown
timestamp: March 19, 2025, 11:36:46 am
content: Quote from: Siwastaja on March 19, 2025, 10:31:43 amHV battery implies some serious safety.48V give me some piece of mind in my DIY installation.If you can afford the copper, 48V are perfectly fine.My home runs on 48V, 57.3KWh DIY battery pack.I am a happy camper with my Victron ESS 48V system.I would have no problem to switch to an HV battery system and save some copper... but I would have to invest more in insulation stuff.

author: Kjelt
author_rank: Super Contributor
timestamp: March 19, 2025, 11:40:21 am
content: Quote from: nctnico on March 16, 2025, 01:43:33 pmThis is the catch:QuoteThis means an additional 700 euros per year out of your pocket to upgrade from 3x25A to 3x35AFor the microinverters being more point of failures, if one fails you still have n-1 working and producing energy.When one panel in a string of panels fails it is over for the entire string.Since my panels are 10+m high on a sloped roof I wait till more fail before going up there or call the maintenance company ($$$)

author: Siwastaja
author_rank: Super Contributor
timestamp: March 19, 2025, 11:58:07 am
content: Quote from: Kjelt on March 19, 2025, 11:40:21 amThis must be some kind of copy-paste error or similar brainfart. I have never heard about any requirement like this, it makes no sense. Of course there is no real requirement of a 3x35A supply. These Growatt inverters are installed in hundreds here, to our usual 3x25A contracts.

author: nctnico
author_rank: Super Contributor
timestamp: March 19, 2025, 12:43:18 pm
content: Quote from: Kjelt on March 19, 2025, 11:40:21 amIt is a single phase inverter for single phase systems. At these kind of power levels, you'd get a 3 phase inverter if you have a 3 phase supply. I'm on a single phase supply with a 40A primary fuse. IOW: it is not a problem at all but they have to specify that you have to have a suitable primary fuse rating for this inverter to operate. The inverter itself is supposed to connect to a 25A circuit and you'll need some room to have enough selectivity between the primary fuse and the fuse the inverter sits behind.

author: David_AVD
author_rank: Super Contributor
timestamp: March 19, 2025, 07:20:13 pm
content: Quote from: Kjelt on March 19, 2025, 11:40:21 amAFAIK on mine only a disconnected cable between panels could cause the whole string to fail. I do have optimisers on them though so get per panel reporting.

author: tszaboo
author_rank: Super Contributor
timestamp: March 19, 2025, 08:52:42 pm
content: Quote from: Kjelt on March 19, 2025, 11:40:21 amA failure on the 230V side would bring down an Enphase system just the same way.But the real failure point for the Enphase systems is software, the gateway, their terrible subscriptions, their mobile app. They sound and act like one of those companies that could push a FW update any time that will brick your device on a moment's notice. I don't trust them at all.

author: Kjelt
author_rank: Super Contributor
timestamp: March 19, 2025, 08:59:51 pm
content: Quote from: tszaboo on March 19, 2025, 08:52:42 pmMwah the gateway was optional so the owner can see the statistics. You did not have to buy the gateway, or even use it. Pull the plug of the gateway and the IQ7s remain operating and producing, don't see the fuzz.

author: nctnico
author_rank: Super Contributor
timestamp: March 19, 2025, 09:03:44 pm
content: Quote from: Kjelt on March 19, 2025, 11:40:21 amThen again, a solar panel is a mostly passive device. Very unlikely to break down. As I wrote before: put as less as possible gear on the roof as it is difficult to access in most cases. Which gets to the point where you need to think about whether retrofitting roofs with solar panels is a good idea to begin with. For my own install I made sure I can access all the connectors from the windows in the roof. If there is a problem in one of the panels, I can disconnect / bypass it without needing to go on the roof.

author: EEVblog
author_rank: Unknown
timestamp: March 19, 2025, 10:48:34 pm
content: Quote from: Zucca on March 19, 2025, 11:36:46 amI'd only go for a HV system if I had a long run.Copper is expensive, but it's not that expensive.

author: Siwastaja
author_rank: Super Contributor
timestamp: March 20, 2025, 06:15:59 am
content: Quote from: Kjelt on March 19, 2025, 08:59:51 pm... which makes the thing unappealing bait-and-switch. "Here, buy this more expensive, more complex, less reliable premium system, but hey, it gives you fancy extra features like per-panel monitoring, which also helps with the unreliability!" ... "you can buy it without the monitoring!" This is like buying a Ferrari with 1.4-liter motor as a cheaper option, no one wants it, it makes no sense.This same pattern is all over microinverters. "Buy this premium thing which produces more from the same light!" ... "By the way, it has worse efficiency, it has insufficient current rating so MPPT flats out in optimum conditions and you lose production, oh and it thermally throttles and you lose production."All that is left is mentalimageof premium, with all premium really stripped off, because their manufacturers failed to keep improving their products. Even failed to keep them up-to-date. And I don't blame the designers, it's a very difficult engineering task.During the same time, string inverters gained two or three MPPT trackers, remote monitoring, and nearly free-of-cost battery port. Just what people wanted and needed. And they do it for cheap.Really, the competition is already over.I can still see there is potential in distributed inverter topology but it needs some significant change in mindset how these things are designed; better integration and even more serious cost-cutting without undermining quality. A harsh equation.

author: Kjelt
author_rank: Super Contributor
timestamp: March 20, 2025, 08:27:03 am
content: I don't see it that black/white Siwastaja.There are other advantages , you can place small setups like two or three panels standalone anywhere you want on your gardenhouse, on a small flat roof.You can distribute easy over the phases, even unbalanced if you know one of the phases is heavier loaded. etc.I choose for it two years ago not for premium but exactly low maintenance if one dies like this topic and more in the coming years.The priceup in that time was 8% so yeah couple of hundreds euro's. Not a big difference as nowadays if I take your word for it.Also not to have a large box somewhere in the house that needs replacement every ten years.That big box might now be used for batterystorage, but I am thinking about building it myself and rather not have it in the house

author: David_AVD
author_rank: Super Contributor
timestamp: March 20, 2025, 09:13:49 am
content: When I got quotes for Enphase micro inverter and Solar Edge string systems, the Enphase was more expensive despite being around 30% lower in output IIRC. The Solar Edge system also has optimisers on every panel.

author: tszaboo
author_rank: Super Contributor
timestamp: March 20, 2025, 10:10:36 am
content: Quote from: David_AVD on March 20, 2025, 09:13:49 amI have the SolarEdge for the past ~5 years. The system always works with optimizers, the inverter is a dumbed down version of regular inverters. The optimizers will generate a fixed voltage, so panels with shading will make 20V 5A for example, panels without shading will make 60V 5A. The total string will make 400V as I recall. Then the inverter only needs to go from this 400V fixed voltage to 230V AC, much simpler than MPPT. The optimizers according to teardowns don't have any electrolytic capacitors in them, and they are completely potted. So no components in them with limited lifetime, the only way I see this broken is thermal cycling induced, or surges. And unlike the Enphase inverters, the optimizers are rated for more power than most panels, no clipping. Well, there could be some clipping, as I have a 3.5KW inverter on a 4KW nominal DC system, but thats rarely an issue for the NetherlandsIt costs more, in my case I think the total system price was ~5% higher than string inverters. But then I have the piece of mind, and the per panel MPPT. If the system pays back in 5 years, it might take 3 months more for it to pay for itself, worst case. Considering that it generates more ,because I do have shading, mine probably paid for itself faster than a string. As far as compromises go, IMHO it's a good one.But that was 5 years ago, panels are cheaper now, the economics have shifted.If you are only after ROI, there are systems that are free here. Some people will give away their 5-10 year old system, you only need to go to disassemble it yourself from their roof. That's hard to beat in price, but I don't really feel like working on a 45 degree slanted roof.

author: nctnico
author_rank: Super Contributor
timestamp: March 20, 2025, 10:14:35 am
content: Quote from: Kjelt on March 20, 2025, 08:27:03 amEven in those situations a string inverter wins. A Growatt 600W inverter costs less than 100 euro.

author: Kjelt
author_rank: Super Contributor
timestamp: March 20, 2025, 11:30:57 am
content: Quote from: nctnico on March 20, 2025, 10:14:35 amDoes it also have 25 years guarantee?

author: Siwastaja
author_rank: Super Contributor
timestamp: March 20, 2025, 11:53:34 am
content: Quote from: Kjelt on March 20, 2025, 11:30:57 amIt is easy to give guarantees - another thing to respect them. Guarantees are marketing things. For example there is a long tradition that the cars known as being most reliable have shortest guarantees. A company which is a sinking ship has nothing to lose, and stuff like building illegal inverters saving costs of the mandatory isolation relay, or giving 25-year guarantees even when you know that you have huge return-% during that time, are last resort attempts to save the business. The very reason for the guarantee is that the whole industry "knows" that microinverters are unreliable. Probably the image of their reliability issues is exaggerated, they are notthatbad really, but the image is very poor, affecting sales. What else can you do but to respond by a long guarantee?Same thing as Korean car manufacturers respond with 7-year warranty when people think "they are not as reliable as the Japanese cars, which I buy anyway even if it only has a 3-year warranty".Quote from: Kjelt on March 20, 2025, 08:27:03 amSorry if I'm blunt, but that sounds like the weirdest mental acrobatics I have seen in a while. If we accept the premise that even a well cooled inverter is cumbersome because it fails and needs a replacement (in an easy access location) andthatcounts as a downside, then I have very bad news for microinverters.To me and many others, the fact that the box is inside and replaceable are positive features.But I have seen this a lot in microinverter marketing: take the most obvious disadvantages, and turn them around 180 degrees. "Better reliability" and "more easy replacement" are examples of claims I actuallyhaveseen before. But it is totally ridiculous from both logical viewpoint and practical experience, if you think about it.

author: nctnico
author_rank: Super Contributor
timestamp: March 20, 2025, 12:10:11 pm
content: I fully agree about having the inverter inside in a place where it is easy to access. Replacing it takes like 10 minutes (assuming the new inverter has the same connectors). And it is not outside the realm of possibilities that future government regulations mandate replacing the inverter for a model with grid management features. I don't see that working well when you have micro-inverters on the roof.For my solar install I planned having to replace the inverter for several reasons: defect, support for home storage or changing government (grid management) requirements.I also agree with warranties are something to take with a grain of salt. Enphase's warranty only applies to the cost of the product itself. Not the cost for doing the actual replacement (which can easely add up to a multitude of the cost of a microinverter). In the end a warranty is an insurance you pay for. Enphase's bet is probably that few people claim the warranty beyond the warranty period from the installer because the cost for sending somebody up on the roof makes it financially unviable. Some people in this thread have already noted that they'll wait for several microinverters to fail before sending somebody up the roof due to cost.

author: Jeroen3
author_rank: Super Contributor
timestamp: March 20, 2025, 12:53:21 pm
content: The Germans are already doing Paragraph 14a.Meanwhile, of my inverters isn't reporting...The one on the highest part of the roof

author: Siwastaja
author_rank: Super Contributor
timestamp: March 20, 2025, 01:32:19 pm
content: Quote from: Jeroen3 on March 20, 2025, 12:53:21 pmIt's good to have some standardization. Hopefully it will be KISS. Because the current situation isn't at all that bad. At the moment, our box for example interfaces with seven different hybrid inverters and four different PV-only inverters. Introduction of support for new models has been completely my job in addition to everything else I am doing, not a huge workload at all, usually it takes a day or two with the Modbus documentation and testing per inverter.So it's entirely possible to live with the current generation of devices - their controllability and communication features are already good enough - and small bits of driver layer modules. Compare to that, SunSpec already exists but the sole SunSpec compatible inverter we support also implements their own non-sunspec interface which is so much simpler that we use just that. SunSpec is a great example of failed standardization. We need something simpler which the Chinese hardware companies can implement without huge software teams.Batteries specifically need some seriously intelligent control to make any financial sense. As PV buffers, they never pay for themselves. We do combined spot price + PV optimization which provides steady flow of savings but even that is too little. Now the big trend are the frequency containment reserve markets and for last 2 years quite lot of money has been on the table, but the market is already collapsing because it is so easily satisfied with a few larger battery sites. It never goes to zero however, so combined spot+PV+FCR optimization is now what we are chasing and which hopefully gives us competitive edge against those who believe that FCR will produce endless flow of money forever.And in the meantime, 99% of batteries sold globally to consumer end-users end up being seriously underutilized, expensive and heavy piles of valuable metals sitting in the homes, doing nothing. That's really sad.

author: EEVblog
author_rank: Unknown
timestamp: March 21, 2025, 12:09:41 am
content: Quote from: Siwastaja on March 19, 2025, 06:39:46 amYes, this is how the world works, and solar is no exception. Doesn't seem like Enphase are going bankrupt.