This is a blanket response to all those below saying I’m wrong about the Christmas tree analogy. To those screaming that it’s wrong and dangerously misleading to use this analogy because it no longer applies because of bypass Diodes, please keep reading. The the Christmas tree light analogy works perfectly in explaining how solar was traditionally wired and installed. Therefore, is both useful and applicable. To say that it is not as like arguing that explaining how internal combustion engines work is no longer necessary. With the advent of modular level electronics such as micro inverters or optimizers used technology to overcome that very problem. Understanding that basic issue will help consumers in understanding how solar works. Bypass diodes are just a new form of a modular level electronics that helps overcome the shade problem. String inverters coupled with panels with bypass diodes may be just as good at controlling the shade as any other technology. That’s a moot point today here in the US where it’s not offered to residential consumers because of the virtual duopoly between Enphase and SolarEdge. Plus, if you just use a string inverter, you lose the advantage of modular level electronics that give you monitoring access at a panel level, which is super important to consumers. If you don’t have that, you won’t know if you have an individual panel out easily. Also to be 100% clear the most important thing for a consumer to do is use an installer that they trust to do a good job and take care of the system for a long time with a good warranty that covers labor. That’s far more important than an individual technology choice you make. Hope this helps clear things up.
Thanks for the clarification in the pinned post. I think quite a few of your viewers will be elsewhere than in the US, where string inverters are alive and well. In Europe where I am, I believe they make up the vast majority of installations (around 80%). At around twice the population size of the US, Europeans matter, as does the rest of the world, of course. I guess it would have been good to at least include the information about bypass diodes in the video: strange to not alert people that the Christmas Lights effect is largely a thing of the past now. The issue wasn't that you mentioned the Christmas Light effect, but that you did not put it in its proper historical/antiquated context. As for monitoring access to individual panels, it is sure neat to have, especially on large installations. Going forward with modern panels, most residential installations will probably be 20 panels or less (especially outside the US where home energy consumption is not as high), and a panel failing represents at least a full 5% production loss. That should be pretty noticeable from monitoring the overall solar production. Finding the offending panel can then be a bit tedious, but totally doable, and probably worth the savings of not shelling out for up to 20 optimisers. But that's just my opinion. A failed panel is probably going to be a vanishingly rare occurrence for 99% of homeowners and if it happens, it is detectable for most residential installations. Anyway the main point is: knowledge of all options is power. Probably best to let people know neither microinverters nor optimizers are nearly as useful as they used to be.
When you say that bypass diodes are 'new' and 'not offered'. What do you mean by that? They come installed in every panel since at least 2010 and I would assume since 1980.
@@Chris-ie9os Would relatively new work for you? What I mean by not offered is the combination of panels with bypass diodes capable of mitigating shade issues coupled with a string inverter is just not offered in the US residential solar market. We have a virtual duopoly here between two inverter companies - neither one of which offers a string inverter.
@@bradthesolarguy ??? SMA, Fronius, Growatt, Sol-Ark, EG4 and Tesla are all examples of string inverters commonly used on the residential market. When is it that you think using bypass diodes started? I'm fairly sure solar panels in ~1980 had bypass diodes. It's a safety requirement.
Comment 250: One huge advantage of micro inverters in a coastal salty environment is that they are closed and have passive cooling. The internals are not exposed to salt and corrosion like a string inverter. Most open electronic equipment close to the beach does not live long. That was for me one of the reasons to use micro inverters beside the fact that you do not loose your whole system when one goes down.
I don't know why everybody is knocking you ( probably the installers ! ) I've been watching Web cast's for over two years now and as far as I'm concerned you have just given the best information i have seen to date. Thank you 😊
Probably because he's LYING about the 'christmas tree' effect? All solar panels have had bypass diodes for DECADES now, so one panel in shade does NOT 'bring down the rest of the string'. That's why bypass diodes were invented, in the 1980s! They are cheap, they work perfectly well, and they are much cheaper and more reliable than 'optimisers', which are a complete waste of money. I have had solar installers tell me that I would need 'optimisers' on my panels, because I had told them that some of the panels are in shade, some of the time, and they told me to my face "If one panel is in shade, it will stop the rest of the panels working." Just ridiculous lies - I know this, because I'd been using the panels for six months, and I know exactly how much power they give out when some are in the shade. Obviously I didn't use that solar installer (I needed electrical work done).
This is the best video I've seen discussing the difference between the types of inverters available. I agree with your assessment. Really well done Brad! The other thing about microinverters is the potential for clipping if the microinverters are not rated for the wattage of the panels installed.
you nailed it. Enphase only outputs 290 Watts from a micro-inverter, yet they have the audacity to rate them as supporting over 400 Watt panels. It's so dishonest. I was really shocked when I read the data sheet and found that the sales people totally ignore this. I can't imagine installing a 430 Watt panel and then spending $175 for a box that clips the output to 290 Watts.
The one issue you didn't address is the cost of swapping out the different inverters when they fail. With an Enphase the company will allow me to do my own install as long as I complete their free online courses and the inverters cost between $159 and $322 depending on which Enphase inverter you chose. On the other hand my gound installed system has two Solaredge inverters which were originally installed by a certified company (because I was getting too old to do the heavy lifting) and when my 10K inverter failed (still under warranty) Solaredge would only allow a company registered with them to evaluate and swap out the inverter. My original installer went out of business so Solaredge will not allow a DIY to activate the inverter to bring it online in a grid tied system. I had already run a diagnostic on the inverter and knew it failed. That required the tech to come to the site twice, once to evaluate that the inverter was dead and then to return weeks later with a remanufactured inverter and install it to the tune of $1800 labor for a total of approximately 30 minutes on site, 10 minutes to evaluate 20 minutes to swap the inverter, unbolt 4 nuts and swap 6 wires and have it update to come on line.
I'm glad to find out we have another way to avoid string inverters. EEVblog on episode 1426 went over an issue he noticed because a tiny amount of shade on a sting inverter system was causing it to produce significantly less power when the shade was there. An easy way to think about the problem with a string inverter is to not mix new & old batteries. This is because the batteries with a lower output is going to encourage the other batteries to try to recharge that one battery & the same thing would happen with a string inverter system.
That was a byproduct of the old SMA inverter he had. I should know because I had the same inverter with the same problem. Basically that era of inverter didn't resweep the MPPT often enough and would remain stuck on a local maxima and not find the new higher local maxima when the shading occurs. Those inverters had two problems actually. One was the MPPT algorithm, the other was that they only had one actual MPPT. In his case, he got smacked by the broken MPPT algorithm. In my case, I got smacked by both (I have two strings). This problem is more or less solved in any SMA inverter made in the last 5 years or so. They call it "ShadeFix" but all it really does is do a more appropriate MPPT I-V sweep a bit more often to find the best MPPT point. Most modern string inverters and charge controllers do this properly now. -Matt
Videos like this one do the most damage because the channel presents well, and the presenter sounds like he knows what he's talking about. 80% of what he says is correct, and is valuable information. This makes it far more likely that the 20% of downright false information imparted will be accepted, absorbed and acted upon by viewers. As others have said, the reality today is that the Christmas light effect really no longer matters. Most panels I'm looking at have three bypass diodes per panel, meaning a 12 panel array is in fact 36 independent solar production zones. Shade one of those zones, and the 35 other zones continue to produce completely normally. You'll only see production drop for the zones that receive shade. The video also fails to specify that even back in the Dark Ages when bypass diodes were not being used in solar panels, the shading issue only really affects situations where there is shading. I know it sounds obvious, but it needs to be spelled out for some folks. MANY installations, if not most, won't suffer from any shading at all. So yeah - really, DC optimizers only really make sense to me if you want per panel monitoring. Otherwise they don't seem to be worth the considerable expense. Just get a good set of modern panels and a good string inverter, and you're good to go.
I don't agree with all your technical points, but I completely agree with the overall message: Microinverters are the least reliable element of a system, and there are a lot of them. I can't imagine the frustration of having them die on a roof. I have a 30 panel ground mount system at my home in Maui, that is grid-tied, with microinverters. The system is about ten years old. At six years microinverters (enphase) started dying. By ten years they were ALL dead. After some protracted communication with Enphase I got a small break on the price of 30 new microinverters and a new whatever they call it that monitors them. No one would come to my house to replace them, my contractor was long ago out of business, new companies looked at the slope of the ground they'd have to work on and said "nope". So I had to replace them myself. I'm 77, and physically active, but it was a tough week. I did manage to find a helper, but that was it. I totally expect the microinverters to start failing again in ten years. I plan to add some additional panels on a less dramatic ground mount and DC couple the series strings to an integrated system--probably a EG4 18K and a wall mount battery. I'll treat the microinverter system as a legacy AC coupled addition that the 18K (and other similar products) can handle and do 500VDC-ish series strings feeding the integrated MPPT controllers. The newest Tesla powerwalls likewise treat AC-coupled systems like yesterday's tech, only they ignore them even more than the integrated offerings from other companies--which has the installer companies going a bit nuts. I'm also building a big container/groundmount 3-phase system at my shop on the mainland, and there won't be a microinverter anywhere in that picture. They made a lot of sense 20 years ago, but they really are legacy tech.
Thanks for your input. Sorry you had to go through all of that. This makes the point that choosing a solar company that's going to take care of you over the long haul is the most important!
@@bradthesolarguy I'm not sure how anyone could actually do that. The list of large solar companies that have gone out of business is incredibly long, the small installers are like any small business--more than 50 percent fail in the first five years.
As you know, Enphase pays to replace failed inverters up to 30 years. Right now Enphase has great reliability with their 5th generation microinverters.
@@robertsheperd502 Perhaps you mean they sort of pay to replace failed ones. Of course they don't actually HAVE any of the old inverters, and the old ones aren't compatible with the new ones, so you wind up having to upgrade all of them--for a discounted price (My replacements wound up costing me several thousand bucks), and then someone has to replace them--they don't pay for the labor. And what does "great reliability" mean? What percentage will fail per year? How many will fail in 20 years? In my view its yesterday's tech. I'm not buying any iPods or pagers either.
@@robertsheperd502 Perhaps you mean they sort of pay to replace failed ones. Of course they don't actually HAVE any of the old inverters, and the old ones aren't compatible with the new ones, so you wind up having to upgrade all of them--for a discounted price--certainly no "free warranty replacement" (My replacements wound up costing me several thousand bucks), and then someone has to replace them--they don't pay for the labor. And what does "great reliability" mean? What percentage will fail per year? How many will fail in 20 years? In my view its yesterday's tech. I'm not buying any iPods or pagers either. 30 or so metal boxes of electronics, under hot solar panels, up on a roof summer and winter, for 20 years. What could possibly be wrong with this scenario?
I’m an engineer that actually has designed solar systems from the utility scale to commercial and residential applications for over 15 years. Dc optimized systems like the ones offered by SolarEdge are garbage. Not because of the technology but because SolarEdge, the largest manufacturer optimizer technology refuses to replace the components when they fail, unless you threaten to take them to court. Microinverters such as those from enphase have the lowest failure rate of any technology and there’s plenty of data to back that up. They actually test for that. But for the average homeowner, that doesn’t have a lot of shading of their roof by trees etc, then latest generation of solar panels (with bypass diodes) coupled with a high quality string inverter will be just fine. It’s not usually worth adding 20%+ to the system cost for a 5% improvement in performance. Also, black on black panels are purely an aesthetic choice but one that makes sense for residential applications as it has wider curb appeal. Most tier 1 manufacturers are making such panels these days at affordable prices. Finally, the statement about subcontractors is hit or miss. It would be ideal to have all work performed in-house by a company with a long track record of solar specific work. But that’s not the reality everywhere. The more realistic solution is to have a dedicated solar installer that has a sales arm that drives business to them. So, technically it’s not subcontracted since all the work is being performed by the contractor but the consultation/sales part is outsourced because those are two different specialties.
Thanks for the comment. I’ve had a much different experience with SolarEdge than you have obviously! And definitely disagree about them being garage. Yes I know that Enphase tests for failure rates. So does SolarEdge. Please show me reliable industry data that Enphase has such low failure rates. Would love that to be true for all those who have them. The cost of the system is nowhere near 20% higher for just a different inverter system in most cases and when you do the math the 5% production gain is well worth it. Agree with you about black on black panels. And agree that not having subcontractors is a magic fix all. It’s just the biggest factor I see again and again in the quality of the install.
Thanks for this video! Now I understand how DC Optimizers can create a more streamlined and efficient system than going the Microinverters route. It sounds like the power optimizers are the least complicated route to go when including battery storage.
LOL. You don't understand anything, because he's LYING. He pretends that bypass diodes don't exist. 'Optimisers' don't do anything that bypass diodes don't already do, they are a waste of money - do some more research on UA-cam, there are videos which prove they don't help in any way.
I think my one year old ground mounted emphase micros are warranted for 25 years so maybe they’ll last a long time? I went with ground mounted solar because the roof needs replacing in a few years but I’m starting to think it’s the best way to go anyways.
It seems everyone only talks about solar panels on the roof. I'm new to solar and trying to design my own system. But the only way I see for a DIY person to install solar is to build a ground mount system. Then maintenance is not an issue, regardless if its replacing a microinverter or brushing the snow off the solar panels. So what are the opinions here - should I go with microinverters or optimisers?
@@sphillips6357 Great question. I think for a ground mount it matters less. Both options are good. If you ever want to add batteries I would go with optimizers so you can DC couple. Otherwise either is good.
Just normal string inverters work very well. Where i live circumstances (normal yield) are worse then in Ottawa. Still a string inverter works very well here. I am in the solar business for more then 10 years and the chistmas tree explanation is just wrong. I prefer not using micro-inverters and really do not like Solaredge (Tigo optimizers are ok, they dont fault)
My SolarEdge inverter failed at the 4th year. I had one optimizer fail on the 6th year. The inverter took 3 months to repair because they had to wait for SolarEdge to send them a replacement. The optimizer only took a week because they had some on hand.
Im a solar tech in california and let me tell you DO NOT get a DC optimizer system. I have serviced tons of solaredge systems and I have encountered customers whos inverters blow out EVERY YEAR. You have no idea how angry they are to find out their system stopped working a year ago and receive a $3000 electric bill. Microinverters are significantly more reliable. Im speaking from over 10 years of solar troubleshooting and diagnostics.
Appreciate your feedback and experience. This makes it clear that no matter what way you go that you need a good company to take care of you. Also, customers should monitor their own systems so they don’t get $3000 surprise electric bills.
Brad says electronics that get through the first year have a full life. Quality Electronics last for decades. If a panel or microinverter fails, you know which one and so can plan to replace it, no searching the array on the roof. Timely action in warranty period. If the supplier disappears in the future, you probably do not need them if your system is reliable and older than one year.
@@bradthesolarguy When Solaredge shut down their 3G cell monitoring it was a year until they had 4G cell cards in stock then they would only allow a certified installer to swap out the 3G card for the 4G card which was an operation that was simple and could be done it minutes.
Hi Brad, fair points below. I’m choosing between microinverters and optimisers and I value the argument about safety: lower (AC) voltages with “simple” AC wiring v very high DC voltages without microinverters. Would you care to comment? Thanks, Paddy
The safety of the DC system will be fine as long as you use good installers and it has good arc fault detection. SMA Sunny Boy inverters and the inverters Tesla uses are safe but the quality of the install is most important. Also, modern panels and string inverters don’t have the Christmas tree affect, so you if you don’t have a lot different shading issues within groups of panels that are on the same string, string inverter is best. If you do have major shading issues case, microinverters from Enphase are your best choice. If shading issues will be negligible within your multiple strings running into the string inverter , then save yourself a lot of money and a lot of repair calls by not getting optimizers placed under each panel. Instead, if you have space, adding more panels with that money will give you the most bang for your buck. If you will have minor shading issues within panels on the same string group, then Tigo optimizers are the most reliable in the world with a significantly lower failure rate than even Enphase microinverters.
I’ve installed micro inverters for 15 years and optimizers for about 10. (And string inverters for 18 years) Optimizers have had a much higher failure rate than micro inverters in my experience and early solar edge inverters have terrible reliability. Bypass diodes on modern solar panels mitigate shading issues in a properly designed system. Cost savings with a modern string inverter is huge and a couple extra solar panels is way cheaper than optimizers or micro inverters.
Thanks for your input. I have had the opposite experience, but that just highlights that an installer with a good labor warranty who will be around is key! Also, the little bit that optimizers improve production is worth the money here (I did the math in another response) and most of my customers don't have room to add any panels.
Totally incorrect regarding string inverters. Most panels from the last five years have bypass diodes. Some are even half or tri-cut. So, while shading a single panel, you will only lose power on that panel, or even a portion of it if it is half cut or tri-cut. And in high heat zones, optimizers or microinverters fail every few years, if manufacturers go out of business, you must find the identical optimizer or microinverter to ensure that the system functions properly. But string inverters can be replaced with any manufacturer's product. The main current disadvantage of string inverters is that you cannot monitor panels individually, however manufacturers like as Huawei are working on solutions for that as well.
Pretty sure it's EVERY panel from the last >20 years. Without bypass diodes shade could cause a fire. So not really optional. Shade doesn't kill strings if they're run independently Can't believe a self professed 'solar guy' wouldn't now this.
~20 years is correct. I have 20-year-old residential panels which have bypass diodes. The "fire" part is not correct. A broken or shaded sub-string in a solar panel just blocks some of the current. No fire. Just less current (which the bypass diode, when present, fixes, by allow current from the other panels to bypass the shaded panel). Any modern-day panel over roughly 200W will have bypass diodes. Tiny little panels like 25W, 50W, 75W, and probably many 100W panels generally don't bother. Larger panels always have bypass diodes these days.
@@junkerzn7312 I learned the importance of bypass diodes the hard way. I built my first array from laminates that didn't have diodes and I wasn't smart enough to install them. In the evening 1 cell was shaded in a string of ~8 panels. That was cell quickly heated up to >200F since >600w was dumped into a 5" x 5" silicon wafer. Pretty sure it would have melted and could have caught fire if I didn't open the circuit.
Interesting vid. I just had a system installed and elected to go with Enphase Microinverters vs. SolarEdge DC optimizers because I repeatedly heard of disastrous quality issues with SolarEdge and the difficulty in getting warranty service. Every Solar installer I spoke to in NH said the same thing except one who said they had turned it around. I was unwilling to test that out and went with Enphase. Only dissapointment is clipping which seems to keep me from getting mkre watts - is that an issue with SolarEdge as well?
Clipping is an issue on either system. I think SolarEdge does a better job with minimizing it, but it really depends on your enphase setup as to how bad it is.
There's a tradeoff between safety and cost. String inverters require rapid shutdown capability to meet the newer NEC requirements and prevent the fire department from letting your house burn down if there's a fire (because you cannot turn off the sun, so the panels are always "hot"). Microinverters will turn off the AC output when you switch off the AC circuit they are connected to (generally, you have to include and exterior solar AC disconnect switch). The newer NEC versions require that there is not active electrical output (AC or DC) outside the boundaries of the panel array when the system is disconnected.
@@surferdudemi i understand that but when your house is on fire no one is worried about turning off the power. first thought is putting it out and saving what you can if you can.
@@hayzersolar Then you should be sure that you can throw an external disconnect so that you can safely extinguish the fire, and the fire department can do likewise.
This is why Enphase and SolarEdge are the Coke and Pepsi of residential solar inverters. They have rapid shutdown and arc control at the panel level built into their technology.
@@bradthesolarguy That only works if the microinverters can see the AC line drop. If you have them connected to the AC load side of a hybrid inverter with battery backup, the microinverters will not see the AC line drop and will not turn off. You need two disconnects: one on the AC line from the grid, and another on the AC line from the inverters to the load side.
Your video was very informative, you obviously know your solar systems. We are retired and live in the UK and we had a 10 panel system installed less than 2 years ago. It was fine at first then the inverter (Solis) started sending alarms which all stated that there was an arc fault which should be dealt with and these have got more frequent lately. The installers came back once and said they found a faulty connecter under one panel and fixed it but the problem persists so I think that more connectors must be faulty. They want to charge me a lot to come back and fix these so I am waiting for another installer to look at the system. I suspect that these connecters are faulty or have not been correctly wired so my question is - is this a common fault with roof panels or do you think we have just been unlucky? I would appreciate your expert opinion on this.
Hi there. Tough situation. Warranties that have good labor coverage by a company that will be around to service it are a must when owning solar if available in your area. Unlucky that you don't have that. You are not alone unfortunately. Not surprising to me that the solar company wants to charge a lot because legitimately electricians are really expensive. They may be gouging you, but you might be surprised by their costs as well. You will know a lot more after the other quote. Could have been faulty installation work, or faulty equipment or both. Electrical stuff can be finicky. My only advice at this point would be to hire the person/company that you trust the most to communicate with you clearly and do the job well. Hope this helps!
I respect most of what you're putting out here but the claim that optimizers have lower failure rates than microonverters runs counter to basically all industry data on the actual failure rates of these rooftop products. Do you have data on a specific optimizer showing long lifespans on them?
Not aware of any residential solar industry data on this topic that I would consider reliable. Mind sharing your sources? I'm genuinely curious. My opinion is based largely on two things. First, I've seen hundreds of systems and have almost never seen an Enphase system that didn't have a bunch of failures and don't think I've ever seen an optimizer failure. Second, inverters are doing the hard job of transforming electricity from one form to another and therefore wear out. Because optimizers are doing a much simpler job I think they have a lower failure rate. That being said, I'm very open to the idea that the micros are as reliable as optimizers. That would be great news for millions of people. But even if that is true, I would still choose a central inverter, which DC optimized system are, over micro-inverters because with micros you have AC coming off the roof and that is a huge problem for combining batteries with the system. It's possible to have an AC coupled battery system (many do!) but it has real and obvious disadvantages to a DC coupled system.
I too disagree, I think Enphase micro inverters are the best,work better in shading hands down,more efficient in the conversion, I would rather have ac coming off my roof, than high voltage dc,much safer.Now as for coupling with batteries you are correct, dc to dc is easier,and your not reconverting,but which one is being used most,already converted ac main power or recoveries dc to dc power. As for micro failures,most I see failing is miss matched panels to wrong micro, ie, 400+w panel into a micro inverter that's only rated for 285 to 305w. Personally I've ran mine for 7+ yrs and Ive had no failures on my complete system. My only regret is not having the IQ 8s when I bought mine, there the only system grid tied that can island themselves in grid down without battery backup,and that my friend is a lot JM2C
Enphase is a good product for shade control. SolarEdge is just as good or a little better for shade control and has DC coupling for batteries. And yes! So many system with too small micro-inverters! Yikes. Paid for all that wattage on the roof and can't access a huge chunk! Bummer.
At least in my area N. California the discrete panel minoring is disabled to the consumer. I think the main reason is to cut down on service calls. People that don't understand the system would be calling their installer right and left when they saw something they think is a problem when it's not.
Interesting. One would at least hope then that the system does log that information and send it to the installer, so if you do have a panel out, they can address that. The cynical view would be that they wouldn't address that at all if the consumer wasn't aware of it.
That is unlikely to have anything to do with your location and everything to do with your installer or lease holder and equipment. The solar company can turn on different views for the homeowner. You should ask them.
Thanks for this. A bit late for me, since my system was installed six years ago, but still enlightening. I don't know if the DC optimizer was even an option back then. But I have found that the microinverters on my system are _incredibly_ *unreliable*. In six years, five have failed so far. There are only 20 to start with, so that's a 25% failure rate in just the first six years, averaging one failure per year. And of course, they are way up on the roof, where it's hard to replace. Fortunately, the installer has been gracious about the whole thing. The inverters are under warranty, but the manufacturer doesn't cover labor. I had to pay labor for the first two repairs, but the installer has agreed to cover labor as these continue to fail, given how unreliable they have been. Who knows if I'll still be in this same house if and when the panels have degraded enough to require replacement, but seems that already, and probably even more so by then, the technology has been advancing quickly. If it weren't for the cost, I'd love to upgrade my 300W panels with 400W ones, and switch to the DC optimizer approach you suggest here.
As long as you have enough space on your roof, it's not going to be worth it to remove the old panels, just add more panels if your system produces insufficient power. Either expand on the microinverter system or add a separate string with inverter. With modern panels you can just use a string inverter and even optimizers are not worth the extra money.
The question some of us would have are, have the microinverter manufacturers learn and adapted from the early failures and now make them more robust and reliable than before, or his this still an issue years later. One would also think like anything else, there are probably micro inverter models and brands that are far more reliable than other brands and models.
Optimizers are fine but increase cost just a tad over micro inverters. Secondly You'll have to replace the inverter aprox every 10 to 15 years on an optimizer system and the warranty is usually 10 years which means out of pocket for a new inverter. Another disadvantage is on a larger system you may need to or more converters which means more money when they fail. Those inverters are very expensive and fail due to the high heat and amount of wattage they are converting thus the reason for 10 year warranty. Micro inverters slightly more efficient , Warranty is 25 years, and according to installers I have spoken with extremely rare to have one fail. One installer that put in well over 200 systems says he had to replace two one which was bad from the get go the other failed in warranty and is a plug in connection. Now for charging a battery advantage does go to optimizers. They deal DC to DC with minimum loses though micro inverter systems even with the loses of converting is extremely low percentage.
SolarEdge and Enphase in the US form a virtual duopoly and their prices are negligibly different. That includes extending the SolarEdge warranty to 25 years. I agree that more converters or inverters are bad because they are more likely to fail. That is why I like Enphase slightly less. Optimizers are not doing the heavy work of inverting and are less likely to fail. 200 systems is not a very big sample size at all. More important than the specific equipment is the company servicing it by far! DC coupled batteries are clearly better in just about every way.
My experience is the opposite, DC optimizers seem to fail way more often then the micro inverters. I've yet to do an enohase replacement, but have run into many soleredge optimizers that failed. With rapid shutdown rules, micros work really well. Batteries, yeah that's marginally better, but it's a fairly minor percentage.
I think choosing an installer you trust to do good work and service the system for many years is your best bet. Let them advise on equipment. I like SolarEdge but go with what your installer recommends.
Unless you have lots of shading, string inverters are fine, and what goes on the roof is simpler and more reliable. I have been using string inverters for years with no issues.
String inverters don't pass National Electrical code for modular level arc control and rapid shutdown. For this reason Enphase and SolarEdge are the Coke and Pepsi of inverters for residential solar.
@@bradthesolarguy Right now I use high voltage DC circuit breakers to short the string outputs which limits the current to an Isc of less than 12 Amps for a string. It effectively clamps all panel outputs to a few millivolts (non-zero due to resistance in the cabling). Works fine. If I worry about some arc damage to the switches on opening to restore normal operation, I can wait until the sun has gone down. The point is that a fireman could close all the breakers and then douse the panels safely, and they would be unlikely to touch the breakers again after they are done.
Interesting. Thanks for the education. Are all microinverters the same? Are there no ones with added tech that voids the issues you talk about like this new one that comes with Anker Solix X1?
No. They are not all the same. There are several different micros from several companies and technology is always changing and advancing. What issue is it that you are hoping the Anker will solve?
@@bradthesolarguy was looking at getting the new Solix X1 inverter and thays where I heard about this microinverter stuff. Was hoping the Anker microinverter under the panels would solve the issue you mentioned about the whole system not working because of one panel since the microinverters each act independently. But now that you say they're not very reliable I might just go with the option you mentioned that's better than microinverters. I'm not a solar boffin and don't know the names and terminology so I hope I'm making sense.
Gotcha! My advice is to choose a good local installer who you trust to communicate clearly with you, do the job well and service the system for a long time. Let them advise on equipment. Why? Because you provably know people better than solar, so choose good people and take their advice. If they plan to be in business for a long time they will have planned how to service the systems and their equipment choices should reflect that. Hope this helps!
@@bradthesolarguy the problem is I live in a country with a very volatile environment, business and otherwise so businesses open and shut down like day and night. My first solar was done by my uncle in 2009 who ran a solar business then. Hybrid system. Did it perfectly. Four solar panels, sinewave inverter Chinese brand (sikui) or something along those lines. Still works today. 2021 got some company that came highly recommended by a family member. Worst mistake ever. Replaced the batteries, added a change over kit or box or whatever it's called. We went from an automated system that changes to solar when the mains go out to a manual system. Following morning woke up to the smell of burning plastic clearly coming from where the batteries are housed. Called him, he came over and checked and said everything was fine. Told him the system doesn't work as the 'battery empty' alarm comes on after a couple of seconds of turning the solar on at night or when cloudy. Long story short he had me change all the globes in the house at $5 per globe for what I later discovered were cheap Chinese globes. To this day the solar system does not work when the sun goes down. I paid almost a thousand dollars for that. It's hard for me to trust any of these solar people now so would rather learn everything myself.
Agree Microinverters does not make sense on when solar panels are in the roof, but if solar panels are in place that is more accessible, it make sense.
Agree with Niall, you lost me when you mentioned about christmas light effect. There are plenty of videos showing actual tests , showing bypass diodes do a lot of the work to bypass the panels which are shaded. Sure microinverters /optimisers may give better/optimal output but these generally only make 3-5% difference, yet cost is around 10-20% more, not to mention, as you say, you may have more maintenance over the long run replacing the microinverters/optimisers.
Please see my reply to Niall as it applies to this questions as well. I am not a fan or micro-inverters. Your point about the cost is a good one. Let's do some math! If my 10 kw system lost 5% a year to shade that would be 500 kwhs a year. That's $200 at last years' utility rates here in Massachusetts. Let's say that stays the same for 25 years (no chance in reality of it not going way up) then that adds up to $5,000 worth (probably a lot more) of utility electricity I'm buying even though I have solar. That's more than 5 x the "savings" I would get from going with a cheap string inverter. I'll stick with my Solaredge inverter which combines the advantages of both a string and micro-inverter while hugely reducing or eliminating all the flaws.
@@freddurstedgebono6029 that is useful info, though working the math it still doesn't seem economic. Assuming one big 500 W panel per optimizer and 5% improvement in yield (both generous assumptions) you get 25 W for $62.50 ... $2.50/W, not as bad as the first panel I got in the '90s (20 W for $200) but not comparable to current prices for just adding more panels (my last purchase was 455 W/ $315 CAD delivered). Even including mounting and install it would make more sense to add panels if you have the room. Of course residential rooftop installs need an RSD to be compliant so that makes the optimizer a reasonable solution but that wasn't the original argument (also not all installs are roof mount). I'd recommend everyone do the math for their own particulars before making decisions.
It really has nothing to do with the cost of the goods. It has to do with the cost to have them installed and maintained. People should compare quotes not do their own math. That would be useless, so I get why you are recommending that.
In the US, if you are roof mounting, either DC optimizers or micro-inverter are absolutely required under every panel for the emergency shutoff feature. Simply stringing the panels is not an option and the whole shading problem therefore disappears.
I’m aware of the existence of shutoff only electronics, but the price difference of ones that also include optimization is so small, I’m amazed it’s profitable to design, manufacture, and inventory both flavors. Agreed from the consumer side, might at well use optimizers, and the whole shading issue disappears.
Optimizers have a higher failure rate than microinverters. You’ll have just as much repairs or more from putting them under each panel. Most modern panels and string inverters don’t have the Christmas tree effect that systems did. That’s why Tesla solar systems are able to perform well without optimizers. Not as well as micro inverters, but significantly better reliability and lower cost.
You nailed it. I studied all the options and the Powerwall 3 with six MPPT wide voltage range DC inputs beats everything. It's all in one box, less things to connect, you can segment to handle shading, less stuff on the roof. My buddy has four and they work great.
Why would anyone put sensitive electronics under panels (especially roof panels) that bake in the sun? And why would you want to deal with repeated trips up on your roof - if you've got tile/slate, the last thing you want is uncaring solar schlubs stomping around breaking tiles. My neighbor had a major roof leak soon after his solar guys came and added some panels. But since it wasn't at the panels themselves, the solar company refused to fix the problem. But it was the access way to the panels that were damaged - nobody else had been on the roof in a few years (it was only a few years old) - multiple tiles were cracked/broken and had punctured the roof sheathing. Cost him a few thousand to fix everything - he had to eat it since he redused to file an insurance claim and see his premiums rise.
They are made to be outside under the panels. They are sealed and only require passive cooling. The fact that they are under the panels means they are not baking in the sun.
Unfortunately a lot of misinformation and confusion surrounds this. Best to check exactly what is the best for your own set, consider: type of panel (split cell etc), shading at various times of the day, ease of access, etc.
Well your video was a good video but you did not mention any DIY systems. I did my complete system myself at my farm. I had a nice unusable hillside that was facing the correct direction for a perfect ground mount. I went with Enphase inverters. My power company allows me to associate other meters with my net metering solar array so I don’t really use a lot of kW’s at my farm but I am able to apply the excess to my home bill. The total installation was somewhat labor intensive but so simple. The money I saved was tremendous. My system will pay for itself in 9 years.
Thanks! I don’t focus on DIY because it’s such a small percentage of people who can do what you did! Amazing. Love your story. And now you have the skills to maintain it and are saving tons of money. So great!
To my knowledge their technology does NOT include DC opimizers. I could be wrong. I'm not an expert on their solar equipment because I've never represented them. My customers for some reason demand customer service.
An advertisement of optimisers. He started by saying string inverters are bad and then moved to inverters and optimisers and then started pouring shit on microinverters. The reality is that optimisers will need a string inverter anyway. Todays solar panels have bypass diods so that the story of one shaded panel ruining the whole string is a BS. I doubt that today optimisers will be needed at all and pay for itself as for the money of optimiser you can buy an additional panel. The solar industry is a wild market where solar installers selling unnecessary devices for unfamiliar people. What customer need is a H-Bridge block which converts DC to a square AC and most of the appliances which using inverters will work without anything else. Who can justify why today we need sine wave AC in the houses where most of the appliances in fact have no need for this?
Again, because of code most solar companies in the US use either Enphase or SolarEdge. Between the two I prefer the SolarEdge system because it acts more like a string inverter. They are both good systems. And there are many other good choices too. But the most important choice is not the technology but making sure the installer will service the system over time.
4 parts to every system panels contoler (you left that out) storage batteries and inverter ... and to obtain efficency first storage then controler .. panels and inverters are least important and don't dump in to the grid. Keep the energy and bank ..never use a all in one contoler and inverter
Not everyone gets batteries with their system, he's just talking about solar here. Battery is an added expense. Might be a wise one, depending on your budget and where you live, but it's not necessary in order to have a working solar system and doesn't always make sense for everyone.
Totally wrong, string inverters works totally fine, there is no "Christmas light effekt". All modern panels has by-pass diodes, so this is not a issue. What planet have you been on the last decade?
What he is saying is that when a string inverter stops working, the whole system stops working, much like one xmas light bulb burning out, causing the whole xmas light string to stop working. String inverters work fine, like you said, until they stop working. Then your whole system stops working.
@@bradthesolarguy LOL. "We are just going to have to disagree." Which means "I'm just going to keep pretending that bypass diodes don't exist, and mislead people with my obviously FALSE 'christmas tree' diagram." Laughable.
Brad says electronics that get through the first year have a full reliable life. Quality Electronics last for decades. Enphase has a good reputation. If a PV panel or microinverter fails, you know which one and so can plan to replace it, no searching the array on the roof with enphase. Timely action in warranty period. Generation is maintained. CASH SAVINGS is maintained. Grid electricity is expensive electricity. If the supplier disappears in the future, you probably will not need them if your system is reliable and older than one year. 240vAC microinverters on a metal roof is a safer situation vs 600vDC. CASH SAVINGS lost adds to COST of cheaper string inverters.
This is misleading. Micros have 25 years of warranty (Enphase) and even if one would fail the rest of the system works great. With an optimizer based systems (Solaredge) both the optimizer and the inverter may fail. And string inverters only have a 10-15 years warranty. In addition, you are running high voltage DC cables on the roof with an optimizer type of system. Micros are a bit more expensive but they give you the piece of mind that your whole system will never fail. It’s AC and it’s safer due to no arching issues. And if you ever want to add panels in a micro system you just slap new panels on with new micros. However, with an optimizer based system you have to resize and buy a new inverter that match the additional panels. If one doesn’t go with Enphase then the Tesla Powerwall 3 with included inverter is the best option. There is no need for optimizers anyways as new solar panels have bypass diods in built that manage shading. Thus optimizer based systems have lost most of their historical advantages.
It's not misleading I just disagree with you. Both Enphase and Solaredge satisfy the Federal mandate for panel level rapid shutdown and arc control. This is the main reason they have a virtual duoplopy for residential inverters here in the US. I recommend extending the Solaredge warranty to 25 years. It costs about $300. Plus the Enphase system has a combiner box which when it fails knocks out the whole system. Solaredge has DC coupled batteries which are much better than what you can do with Enphase. No you can't just slap a few more panels on with Enphase at all! Most places here in the US that means an equal amount of paperwork as the original install. Permits, Interconnection, fire code, structural etc. In the real world though if you own your system I think you are likely to have more solar up time with SolarEdge than Enphase. This is highly influenced by the installation company as ultimately how things are repaired overtime will come down to them. Are they in business? Are they willing to eat the crappy money the warranties (both Solaredge and Enphase) pay for service calls and replacing parts? When a couple micros go out are they going to fix them or are they going to wait for 5 or 10 to go out to make rolling trucks worth it? Please note this all pertains to owning your own system. Warranties are not an issue with leases.
@@bradthesolarguy Well you can disagree but talk to installers and they all say there are much more quality issues with Solaredge than Enphase. And yes, you can just slap more panels and micros on if you want to enlarge your system. With Solaredge you have to buy a completely new expensive inverter. The permit times are irrelevant to that fact. There will be no optimizer in the future as they provide no real advantage to new solar panels dealing inherently with panel shading (diode bypass). Solaredge is most likely even bankrupt in a few years so that warranty goes poof. Check their company performance and losses so you understand.
@@bradthesolarguy It’s well known among installers that the quality of Solaredge is not on the same level as Enphase. And not even talking about the warranty and customer service. Maybe you should take up your head from the sand before Solaredge goes bankrupt and you and your installer buddies along with that? Warranty says poof!
Can’t really hear you with all that sand in your mouth. There are many people, maybe more, who agree with me. And I happen to know and respect some of those people as I have worked with them for years. Do you have anything other than internet experience?
Not at all like a string of Christmas lights. Modern string inverters have multiple MPPT inputs, often four or six. So you have six strings of lights. The MPPT voltage range is often very wide, 60V up to 400Volts. So long it is possible to shade several panels in a string and still get the full power from the other panels so long as the illuminated panels are above the minimum MPPT voltage. It's time to stop telling the same old misleading Christmas light story. It's not 1980.
It's true that technology has improved, but the Christmas light analogy is still a good way to illustrate how they can be affected by shading. Also, string inverters do out pass code in the US.
I prefer a string inverter system - less to go wrong, much cheaper, and in most use cases, any differential panel shading only occurs at the start or end of the day, when not much power is available anyway. Secondly I would go with a hybrid inverter with build in solar chargers, such as EG4 18K or 12k which supports back-feeding the grid as well as power-shifting. These systems need to be used with batteries. I also like the EG4 LFP 48V nominal batteries - at around $1100 per 5KWh, they are a good deal, and should last decades if the daily discharge depth cycle is limited to less than 50% on average.
Sol-ark 15k is far better and you do not have to have a battery. The customer support is far better then EG4. You don't buy lithium just to use only half of it's capabilities You might as well go with a lead acid battery then you would only use that 50%. Lithium you can go from 100 to 0% You still going to get 15 years out of it but decades no, you're not getting decades out of any lithium battery just because you only using half of it
@@TheFatman819 Possibly, although the EG4 units are also reliable. A Sol-ark is much more expensive than the EG4 units. Cycle life of LFP batteries is a combination of calendar aging and cycle aging. If a battery is rated at 7000 full cycles, it means that discharging to 50% each day it should last about 14000 days or 38 years. That well exceeds the calendar aging limit of 15+ years according to the manufacturer. What ages batteries is SOCs below 10% and above 95%, charging temperatures below 50F and above 100F, and charge rates above 0.5C (i.e. 50Amps for 100Ah batteries). I keep our batteries between 60F and 75F over all seasons. I use more batteries to reduce charge rates to < 0.2C, and also deal with cloudy periods in Winter.
They have 50 year old panels making ~60% of rated power.....degradation is no worry are panels will be so cheap soon (see Rethinx) that it will be almost nothing to do so.
Solar installers in FL have a worse reputation than used car dealers, for good reason. My GF solar edge solar inverter was toast in 4 years then the installer wanted $400 just to show up and "diagnose" the issue even though they already knew it was fried from the web connection.
Deye hybrid inverter solve the problem with storage of energy in the battery because of the generatorport. My oldest micro inverter is 22 years old. If you don't buy a Chinese micro inverter it will last forever.
I'm in the middle of evaluating quotes for a roof solar installation and your comparison of microinverters vs optimizers can't come at a better time. Thank you!
Glad to hear it. Please remember I think the installer and their ability to service the system I think is more important than the technology. Hope that makes sense.
Check his advice; it's not complete at best. Do your own homework; look at DIY Solar Power with Will Prowse here on UA-cam. He's a bit all over the place but his information is dead accurate. With optimizers, you still need a DC-to-DC converter to normalize the voltage for either supplying to the grid or putting it into a battery. And if you're going to install batteries, you might as well buy one and cry once and put in a proper Victron or EG4 system. Once you price all that in, you'll figure out why a lot of focus opt for a solid solar company with SLAs on warranty work and micro-inverters. Let their guys and gals climb onto your roof. Or do whatever you want, I don't care, it's your money and headache later.
Yes, what better time than when some poor sod like you, who doesn't know all the ins and outs of solar, asks for advice, and gets lies from a LIAR, who pretends that bypass diodes don't exist. Bad advice is worse than no advice.
@@niallparker3655 In residential solar there are three choices of inverter types from major manufacturers. In the US micro inverters made by Enphase have a huge market share and have all the issues I point out in the video. This is the reality of the marketplace. Are you saying that everyone should just use string inverters? That’s not what’s happening.
@@bradthesolarguy I do think most people would be better served by string inverters, many you tubers have videos on the minimal benefit provided by either micro-inverters or optimizers, certainly not economic and only useful in a few edge cases. Check out what others have found or better yet try a few experiments yourself before you parrot the marketing from Enphase and their ilk ...
@@niallparker3655 Not parroting anybody. I'm using my knowledge and experience of being in solar for 10 years. Are you parroting someone? I'm talking about the actual residential solar market in the US where, right or wrong, almost all companies are installing a non-string inverter on every job. That means half or more of those jobs use micro-inverters which I recommend against. I have no problem with people using a string inverter if conditions merit. Conditions in New England usually do not.
@@bradthesolarguy sounding a little defensive there mate ! ... ;) ... I guess if it isn't your own research then likely we both are parroting to a degree. I agree residential seems to be mostly non-string inverters but the reasons seem more marketing than technical. My issue with your video is that you seem oblivious to the actual performance of a shaded string with bypass diodes and unaware of multiple people demonstrating that these simple strings (no DC optimizer) do perform OK and are simpler/cheaper. Given you are marketing yourself as an expert in solar, seems worthwhile you educate yourself further, maybe try a few tests in your local environment and quantify how bad a simple string really is.
Umm, I may sound defensive because you said I was parroting marketing speak from Enphase and their ilk, which was not only wrong it was insulting. Thank you for agreeing that residential solar is mostly non- string inverters as that is the fact. Not oblivious to anything you are saying, but my goal is to provide useful information not academic. Truth is that, in the real world, solar installers aren't using string inverters for residential use. Further, where I live shade caused by trees, hills and mountains, snow and clouds affect every system. Because these systems will last decades a small percentage gain in production is well worth some additional up front cost. With leases or PPA's, the equipment has to be pre-approved by the lease company. Keep in mind the lease company makes their money by maximizing production versus installation and maintenance costs over 25 years. I don't know of any residential lease or PPA providers who have approved string inverters for residential solar in the Northeast of the United Sates. Wonder why that is?
@@bradthesolarguy In a string inverter system, solar panels are connected in "strings" of 6-16 modules, and the power then flows through the string inverter. The voltage of a single module is around 40-50 V, but when 20-30 modules are connected in series, the DC voltage of the entire system can reach 1,000-1,500 V. This high-voltage DC current then runs across the roof...any arcing can cause fire or death to anyone nearby.
Only if you are not connected to the grid. Otherwise, in most cases not at all necessary. I think of solar as a less expensive alternative to grid electricity and a battery system as a luxury you pay for. Of course, this all depends on how good the local net metering policy is too!
@@bradthesolarguy I guess maybe that depends on where you live and whether or not net metering is available? In Germany where I'm writing from there is no net metering. I pay much more for electricity I buy than for what I get fro electricity I sell ( 4 or 5 times more). And a lot of our usage is before or after peak solar generation hours. With a 10 kWh battery, we use virtually zero grid energy between April and September because of the buffer the battery affords. It is a different story in the winter of course. Having a heat pump with a hot water storage tank also helps (it effectively acts as another 'battery' heating water when there is a lot of sun and keeping it hot enough to use in the evening and when there is no sun)
Yes. Thanks for sharing. The net metering policy of your utility makes a big difference in whether batteries only used for back up power or if used to move solar electricity from day to night.
OK! This is a rather dumb slant on what is probably intrinsically poor product design from certain vendors. Yes, Micro-inverters can fail if they are not used inside the specified range of current and voltage in/out. Yes, DC optimizers can fail if they are not used inside the specified range of current and voltage in/out. The bottom line is that BOTH of these devices are actually electronic switch-mode inverters. And BOTH can and will fail if used beyond their claimed ratings. The input from solar panels to the DC optimizer or micro-inverter is the same. The OUTPUTS are not. And there are minor differences in the way such systems can be wired. The main advantage of the DC optimizer over Micro-inverter is greater simplicity. Because it is basically a tried and true DC-DC buck-boost switch-mode technology coupled with MPPT input load optimization to "sum energy" into a common bus back to the actual DC - AC inverter powering your home. The more common topology is to use DC optimizers under solar panels to directly charge a local battery storage system. This is cheaper, more efficient and more reliable overall. The DC-AC inverter to power your home then is from the battery only. Some readers may find this helpful... www.mysolarquotes.co.nz/blog/how-solar-power-works/micro-inverters-vs-string-inverters-a-comprehensive-guide/#:~:text=The%20power%20rating%20of%20a,of%20235%2D440%2B%20W.
I totally disagree. The US and the state of Massachusetts where I live, have strict code and permitting processes in place to make sure solar is safe. No one is routing any dangerous electricity across anywhere when following code, the UL listed manufacturers installation guides and passing inspection among many other safety requirements ALL of which are required before you can turn the system on. What you’re saying is dangerous, not DC electricity.
This is ass-hat advice. As you said, everything breaks. If a single micro-inverter goes down, you still have solar production until the crew comes out to replace that micro-inverter. I have Enphase on my roof and have had two failures in the four years our system has been online, and both of those failures were in the first 90 days. Also, you said something categorically incorrect. The solar panels don't just pour into the batteries. That's a fast way to kill your batteries because they can't handle the input voltage. You have to use a DC-to-DC charger.
So your failures were within the first year? Checks out with what he was saying. I agree with you that the solar panel to battery isn't a direct wire connection. He was noting that with micro-inverters you have to have a an AC-DC converter before the battery can receive the juice (charge controller not withstanding) and then you have to use a DC-AC inverter like any other battery system or non-microinverter system to use the power. I believe he left out the nuance of battery charging because it was outside the scope of what he wanted to cover in the video which was the many types of Solar Panels not battery charging systems.
It is only about how it looks. Without the black back sheet you see the grid design and a bluish color usually in the panels. The black on black panels look a lot better!
It's not only looks, even though the differences are incredibly minor the same panel with a white back sheet will run ever so slightly cooler and very slightly absorb more light. Usually any line of panels that are available in bothe white and black backsheet configurations there is usually a 2-4% increase in the performance of the white back sheet versions. Since it's so small most people don't care and would rather the nicer looking full black panel.
@@Snerdles Correct. But don’t get confused. A 400 watt either way is the same. So the white back sheets make it slightly cheaper. Not enough to overcome the ugliness through!
You claim panels are "going to last decades". So sure, 21 years is "decades", but I assume most people understand that to mean "at least 30 years". Do you have any evidence that panels last 20+, 30+ years? I'm skeptical that there are enough 30-50 year old panels in service today to make any meaningful prediction about the life of current panels.
The industry standard is a 25 year manufacturers warranty. The technology has been in use for over 65 years. So there is tons of evidence they will last a long time.
Why would I install ANY expensive, critical devices that, as you say, are guaranteed to fail. DC, micro or otherwise? I have yet to see any ROI projections that include these costs. Solar as sold today is a fraud.
Inverting the electricity is a must for tit to run in your home. All solar includes this cost. ROI on solar depends on your situation with electricity rates, netmetering and your roof. The roi on my system is north of 15% annually for the first 8 years and that roi increases every year!
@@bradthesolarguy LoL You've dodged my comment's point. No ROI projections I have seen factor in the replacement cost of those "guaranteed to fail" inverters - DC string or AC mico. Without a accurate cost basis, such fake projections are misleading. If the failure rates of all types of inverters is as high as you say you know them to be, leaving out that cost is fraudulent. The same goes for any batteries that are expected to need replacement due to known issues.
@@kn4cc755 Not sure I follow your logic here. A 5kW solar array in my area is around $17,000 installed. A 5kW solar inverter is around $750 or so. If it fails every 10 years, we are talking about $75 a year in additional annual operating cost. A 5kW solar array in my area would generate roughly $1505 worth of electricity annually. If we factor in the inverter failure, it is producing $1430 worth of electricity annually. So, the solar array would pay for itself in 11.3 years without the inverter failure, and in 11.9 years with the inverter being replaced every 10 years. So, why would this shift of a few months make solar a fraud...? Not following the math here...
This is a blanket response to all those below saying I’m wrong about the Christmas tree analogy. To those screaming that it’s wrong and dangerously misleading to use this analogy because it no longer applies because of Bypass Diodes, please keep reading. The Christmas tree light analogy works perfectly in explaining how solar was traditionally wired and installed. Therefore, it is both useful and applicable. To say that it is not is like arguing that explaining how internal combustion engines work is no longer necessary. Modular level electronics such as micro inverters or optimizers use technology to overcome that very problem. Understanding that basic issue will help consumers in understanding how solar works. Bypass Diodes are just a new form of a modular level electronics that helps overcome the shade problem. String inverters coupled with panels with bypass diodes may be just as good at controlling the shade as any other technology. That’s a moot point today here in the US where it’s not offered to residential consumers because of the virtual duopoly between Enphase and SolarEdge. Plus, if you just use a string inverter, you lose the advantage of modular level electronics that give you monitoring access at a panel level, which is super important to consumers. If you don’t have that, you won’t know if you have an individual panel out easily. Also to be 100% clear the most important thing for a consumer to do is use an installer that they trust to do a good job and take care of the system for a long time with a good warranty that covers labor. That’s far more important than an individual technology choice you make. Hope this helps clear things up.
There's nothing new about bypass diodes. They've been standard in all solar panels probably since the first use of solar panels. The 'Christmas light effect' was never a thing with the exception of parallel strings. If one string is shaded in parallel with an unshaded string you can lose the unshaded portion of the shaded string. This is easily avoided by running each string to its own MPPT.
This is a blanket response to all those below saying I’m wrong about the Christmas tree analogy. To those screaming that it’s wrong and dangerously misleading to use this analogy because it no longer applies because of bypass Diodes, please keep reading. The the Christmas tree light analogy works perfectly in explaining how solar was traditionally wired and installed. Therefore, is both useful and applicable. To say that it is not as like arguing that explaining how internal combustion engines work is no longer necessary.
With the advent of modular level electronics such as micro inverters or optimizers used technology to overcome that very problem. Understanding that basic issue will help consumers in understanding how solar works. Bypass diodes are just a new form of a modular level electronics that helps overcome the shade problem. String inverters coupled with panels with bypass diodes may be just as good at controlling the shade as any other technology. That’s a moot point today here in the US where it’s not offered to residential consumers because of the virtual duopoly between Enphase and SolarEdge. Plus, if you just use a string inverter, you lose the advantage of modular level electronics that give you monitoring access at a panel level, which is super important to consumers. If you don’t have that, you won’t know if you have an individual panel out easily.
Also to be 100% clear the most important thing for a consumer to do is use an installer that they trust to do a good job and take care of the system for a long time with a good warranty that covers labor. That’s far more important than an individual technology choice you make. Hope this helps clear things up.
Thanks for the clarification in the pinned post. I think quite a few of your viewers will be elsewhere than in the US, where string inverters are alive and well. In Europe where I am, I believe they make up the vast majority of installations (around 80%). At around twice the population size of the US, Europeans matter, as does the rest of the world, of course.
I guess it would have been good to at least include the information about bypass diodes in the video: strange to not alert people that the Christmas Lights effect is largely a thing of the past now. The issue wasn't that you mentioned the Christmas Light effect, but that you did not put it in its proper historical/antiquated context.
As for monitoring access to individual panels, it is sure neat to have, especially on large installations. Going forward with modern panels, most residential installations will probably be 20 panels or less (especially outside the US where home energy consumption is not as high), and a panel failing represents at least a full 5% production loss. That should be pretty noticeable from monitoring the overall solar production. Finding the offending panel can then be a bit tedious, but totally doable, and probably worth the savings of not shelling out for up to 20 optimisers. But that's just my opinion. A failed panel is probably going to be a vanishingly rare occurrence for 99% of homeowners and if it happens, it is detectable for most residential installations. Anyway the main point is: knowledge of all options is power. Probably best to let people know neither microinverters nor optimizers are nearly as useful as they used to be.
When you say that bypass diodes are 'new' and 'not offered'. What do you mean by that? They come installed in every panel since at least 2010 and I would assume since 1980.
@@Chris-ie9os Would relatively new work for you? What I mean by not offered is the combination of panels with bypass diodes capable of mitigating shade issues coupled with a string inverter is just not offered in the US residential solar market. We have a virtual duopoly here between two inverter companies - neither one of which offers a string inverter.
@@malk6277 You make very good points. My customers seem to all very much want per panel monitoring, but agree there are ways around it.
@@bradthesolarguy ??? SMA, Fronius, Growatt, Sol-Ark, EG4 and Tesla are all examples of string inverters commonly used on the residential market. When is it that you think using bypass diodes started? I'm fairly sure solar panels in ~1980 had bypass diodes. It's a safety requirement.
Comment 250: One huge advantage of micro inverters in a coastal salty environment is that they are closed and have passive cooling. The internals are not exposed to salt and corrosion like a string inverter. Most open electronic equipment close to the beach does not live long. That was for me one of the reasons to use micro inverters beside the fact that you do not loose your whole system when one goes down.
I don't know why everybody is knocking you ( probably the installers ! ) I've been watching Web cast's for over two years now and as far as I'm concerned you have just given the best information i have seen to date. Thank you 😊
Thanks!
Probably because he's LYING about the 'christmas tree' effect? All solar panels have had bypass diodes for DECADES now, so one panel in shade does NOT 'bring down the rest of the string'. That's why bypass diodes were invented, in the 1980s! They are cheap, they work perfectly well, and they are much cheaper and more reliable than 'optimisers', which are a complete waste of money. I have had solar installers tell me that I would need 'optimisers' on my panels, because I had told them that some of the panels are in shade, some of the time, and they told me to my face "If one panel is in shade, it will stop the rest of the panels working." Just ridiculous lies - I know this, because I'd been using the panels for six months, and I know exactly how much power they give out when some are in the shade. Obviously I didn't use that solar installer (I needed electrical work done).
This is the best video I've seen discussing the difference between the types of inverters available. I agree with your assessment. Really well done Brad! The other thing about microinverters is the potential for clipping if the microinverters are not rated for the wattage of the panels installed.
Thanks, glad you found it helpful! So true about mismatching the micro inverters with panels wattage.
you nailed it. Enphase only outputs 290 Watts from a micro-inverter, yet they have the audacity to rate them as supporting over 400 Watt panels. It's so dishonest. I was really shocked when I read the data sheet and found that the sales people totally ignore this. I can't imagine installing a 430 Watt panel and then spending $175 for a box that clips the output to 290 Watts.
The one issue you didn't address is the cost of swapping out the different inverters when they fail. With an Enphase the company will allow me to do my own install as long as I complete their free online courses and the inverters cost between $159 and $322 depending on which Enphase inverter you chose. On the other hand my gound installed system has two Solaredge inverters which were originally installed by a certified company (because I was getting too old to do the heavy lifting) and when my 10K inverter failed (still under warranty) Solaredge would only allow a company registered with them to evaluate and swap out the inverter. My original installer went out of business so Solaredge will not allow a DIY to activate the inverter to bring it online in a grid tied system. I had already run a diagnostic on the inverter and knew it failed. That required the tech to come to the site twice, once to evaluate that the inverter was dead and then to return weeks later with a remanufactured inverter and install it to the tune of $1800 labor for a total of approximately 30 minutes on site, 10 minutes to evaluate 20 minutes to swap the inverter, unbolt 4 nuts and swap 6 wires and have it update to come on line.
Good points. Service down the road is going to be an issue for all owners of solar.
I'm glad to find out we have another way to avoid string inverters. EEVblog on episode 1426 went over an issue he noticed because a tiny amount of shade on a sting inverter system was causing it to produce significantly less power when the shade was there.
An easy way to think about the problem with a string inverter is to not mix new & old batteries. This is because the batteries with a lower output is going to encourage the other batteries to try to recharge that one battery & the same thing would happen with a string inverter system.
Maybe people will like this analogy better than the Xmas tree light one! Thanks for sharing.
That was a byproduct of the old SMA inverter he had. I should know because I had the same inverter with the same problem. Basically that era of inverter didn't resweep the MPPT often enough and would remain stuck on a local maxima and not find the new higher local maxima when the shading occurs.
Those inverters had two problems actually. One was the MPPT algorithm, the other was that they only had one actual MPPT. In his case, he got smacked by the broken MPPT algorithm. In my case, I got smacked by both (I have two strings).
This problem is more or less solved in any SMA inverter made in the last 5 years or so. They call it "ShadeFix" but all it really does is do a more appropriate MPPT I-V sweep a bit more often to find the best MPPT point. Most modern string inverters and charge controllers do this properly now.
-Matt
Videos like this one do the most damage because the channel presents well, and the presenter sounds like he knows what he's talking about. 80% of what he says is correct, and is valuable information. This makes it far more likely that the 20% of downright false information imparted will be accepted, absorbed and acted upon by viewers.
As others have said, the reality today is that the Christmas light effect really no longer matters. Most panels I'm looking at have three bypass diodes per panel, meaning a 12 panel array is in fact 36 independent solar production zones. Shade one of those zones, and the 35 other zones continue to produce completely normally. You'll only see production drop for the zones that receive shade.
The video also fails to specify that even back in the Dark Ages when bypass diodes were not being used in solar panels, the shading issue only really affects situations where there is shading. I know it sounds obvious, but it needs to be spelled out for some folks. MANY installations, if not most, won't suffer from any shading at all.
So yeah - really, DC optimizers only really make sense to me if you want per panel monitoring. Otherwise they don't seem to be worth the considerable expense. Just get a good set of modern panels and a good string inverter, and you're good to go.
Please see my pinned response above.
The immediate future is using the AC current.
An extra panel will easily overcome a small efficiency loss.
I don't agree with all your technical points, but I completely agree with the overall message: Microinverters are the least reliable element of a system, and there are a lot of them. I can't imagine the frustration of having them die on a roof. I have a 30 panel ground mount system at my home in Maui, that is grid-tied, with microinverters. The system is about ten years old. At six years microinverters (enphase) started dying. By ten years they were ALL dead. After some protracted communication with Enphase I got a small break on the price of 30 new microinverters and a new whatever they call it that monitors them. No one would come to my house to replace them, my contractor was long ago out of business, new companies looked at the slope of the ground they'd have to work on and said "nope". So I had to replace them myself. I'm 77, and physically active, but it was a tough week. I did manage to find a helper, but that was it. I totally expect the microinverters to start failing again in ten years. I plan to add some additional panels on a less dramatic ground mount and DC couple the series strings to an integrated system--probably a EG4 18K and a wall mount battery. I'll treat the microinverter system as a legacy AC coupled addition that the 18K (and other similar products) can handle and do 500VDC-ish series strings feeding the integrated MPPT controllers. The newest Tesla powerwalls likewise treat AC-coupled systems like yesterday's tech, only they ignore them even more than the integrated offerings from other companies--which has the installer companies going a bit nuts. I'm also building a big container/groundmount 3-phase system at my shop on the mainland, and there won't be a microinverter anywhere in that picture. They made a lot of sense 20 years ago, but they really are legacy tech.
Thanks for your input. Sorry you had to go through all of that. This makes the point that choosing a solar company that's going to take care of you over the long haul is the most important!
@@bradthesolarguy I'm not sure how anyone could actually do that. The list of large solar companies that have gone out of business is incredibly long, the small installers are like any small business--more than 50 percent fail in the first five years.
As you know, Enphase pays to replace failed inverters up to 30 years. Right now Enphase has great reliability with their 5th generation microinverters.
@@robertsheperd502 Perhaps you mean they sort of pay to replace failed ones. Of course they don't actually HAVE any of the old inverters, and the old ones aren't compatible with the new ones, so you wind up having to upgrade all of them--for a discounted price (My replacements wound up costing me several thousand bucks), and then someone has to replace them--they don't pay for the labor. And what does "great reliability" mean? What percentage will fail per year? How many will fail in 20 years? In my view its yesterday's tech. I'm not buying any iPods or pagers either.
@@robertsheperd502 Perhaps you mean they sort of pay to replace failed ones. Of course they don't actually HAVE any of the old inverters, and the old ones aren't compatible with the new ones, so you wind up having to upgrade all of them--for a discounted price--certainly no "free warranty replacement" (My replacements wound up costing me several thousand bucks), and then someone has to replace them--they don't pay for the labor. And what does "great reliability" mean? What percentage will fail per year? How many will fail in 20 years? In my view its yesterday's tech. I'm not buying any iPods or pagers either. 30 or so metal boxes of electronics, under hot solar panels, up on a roof summer and winter, for 20 years. What could possibly be wrong with this scenario?
Voltage is very important due to max volt inputs to charge controller inveter. The cooler a panel is the more power it puts out.
Greetings from Italy. Very helpful, thanks!
Greetings!
I’m an engineer that actually has designed solar systems from the utility scale to commercial and residential applications for over 15 years.
Dc optimized systems like the ones offered by SolarEdge are garbage. Not because of the technology but because SolarEdge, the largest manufacturer optimizer technology refuses to replace the components when they fail, unless you threaten to take them to court.
Microinverters such as those from enphase have the lowest failure rate of any technology and there’s plenty of data to back that up. They actually test for that.
But for the average homeowner, that doesn’t have a lot of shading of their roof by trees etc, then latest generation of solar panels (with bypass diodes) coupled with a high quality string inverter will be just fine. It’s not usually worth adding 20%+ to the system cost for a 5% improvement in performance.
Also, black on black panels are purely an aesthetic choice but one that makes sense for residential applications as it has wider curb appeal. Most tier 1 manufacturers are making such panels these days at affordable prices.
Finally, the statement about subcontractors is hit or miss. It would be ideal to have all work performed in-house by a company with a long track record of solar specific work. But that’s not the reality everywhere. The more realistic solution is to have a dedicated solar installer that has a sales arm that drives business to them. So, technically it’s not subcontracted since all the work is being performed by the contractor but the consultation/sales part is outsourced because those are two different specialties.
Thanks for the comment. I’ve had a much different experience with SolarEdge than you have obviously! And definitely disagree about them being garage. Yes I know that Enphase tests for failure rates. So does SolarEdge. Please show me reliable industry data that Enphase has such low failure rates. Would love that to be true for all those who have them. The cost of the system is nowhere near 20% higher for just a different inverter system in most cases and when you do the math the 5% production gain is well worth it. Agree with you about black on black panels. And agree that not having subcontractors is a magic fix all. It’s just the biggest factor I see again and again in the quality of the install.
@@LifeLongLearner-om8jx Agree. This guy doesn’t know what he is talking about 🤦🏻♂️
Thanks for this video! Now I understand how DC Optimizers can create a more streamlined and efficient system than going the Microinverters route. It sounds like the power optimizers are the least complicated route to go when including battery storage.
I think so!
LOL. You don't understand anything, because he's LYING. He pretends that bypass diodes don't exist. 'Optimisers' don't do anything that bypass diodes don't already do, they are a waste of money - do some more research on UA-cam, there are videos which prove they don't help in any way.
I think my one year old ground mounted emphase micros are warranted for 25 years so maybe they’ll last a long time? I went with ground mounted solar because the roof needs replacing in a few years but I’m starting to think it’s the best way to go anyways.
Groundmounts are great! Most locations are not suitable but when possible can be a great way to go.
It seems everyone only talks about solar panels on the roof. I'm new to solar and trying to design my own system. But the only way I see for a DIY person to install solar is to build a ground mount system. Then maintenance is not an issue, regardless if its replacing a microinverter or brushing the snow off the solar panels. So what are the opinions here - should I go with microinverters or optimisers?
@@sphillips6357 Great question. I think for a ground mount it matters less. Both options are good. If you ever want to add batteries I would go with optimizers so you can DC couple. Otherwise either is good.
Just normal string inverters work very well. Where i live circumstances (normal yield) are worse then in Ottawa. Still a string inverter works very well here. I am in the solar business for more then 10 years and the chistmas tree explanation is just wrong. I prefer not using micro-inverters and really do not like Solaredge (Tigo optimizers are ok, they dont fault)
String inverters can be really great. Solar is awesome!
My SolarEdge inverter failed at the 4th year. I had one optimizer fail on the 6th year. The inverter took 3 months to repair because they had to wait for SolarEdge to send them a replacement. The optimizer only took a week because they had some on hand.
Appreciate you sharing your story.
Im a solar tech in california and let me tell you DO NOT get a DC optimizer system. I have serviced tons of solaredge systems and I have encountered customers whos
inverters blow out EVERY YEAR. You have no idea how angry they are to find out their system stopped working a year ago and receive a $3000 electric bill.
Microinverters are significantly more reliable.
Im speaking from over 10 years of solar troubleshooting and diagnostics.
Appreciate your feedback and experience. This makes it clear that no matter what way you go that you need a good company to take care of you. Also, customers should monitor their own systems so they don’t get $3000 surprise electric bills.
Brad says electronics that get through the first year have a full life.
Quality Electronics last for decades.
If a panel or microinverter fails, you know which one and so can plan to replace it, no searching the array on the roof.
Timely action in warranty period.
If the supplier disappears in the future, you probably do not need them if your system is reliable and older than one year.
I do not understand. I am billed 4 times a year.
@@bradthesolarguy Maybe you should listen to @CellTeam6?
@@bradthesolarguy When Solaredge shut down their 3G cell monitoring it was a year until they had 4G cell cards in stock then they would only allow a certified installer to swap out the 3G card for the 4G card which was an operation that was simple and could be done it minutes.
Hi Brad, fair points below. I’m choosing between microinverters and optimisers and I value the argument about safety: lower (AC) voltages with “simple” AC wiring v very high DC voltages without microinverters. Would you care to comment? Thanks, Paddy
The safety of the DC system will be fine as long as you use good installers and it has good arc fault detection. SMA Sunny Boy inverters and the inverters Tesla uses are safe but the quality of the install is most important.
Also, modern panels and string inverters don’t have the Christmas tree affect, so you if you don’t have a lot different shading issues within groups of panels that are on the same string, string inverter is best. If you do have major shading issues case, microinverters from Enphase are your best choice. If shading issues will be negligible within your multiple strings running into the string inverter , then save yourself a lot of money and a lot of repair calls by not getting optimizers placed under each panel. Instead, if you have space, adding more panels with that money will give you the most bang for your buck. If you will have minor shading issues within panels on the same string group, then Tigo optimizers are the most reliable in the world with a significantly lower failure rate than even Enphase microinverters.
I’ve installed micro inverters for 15 years and optimizers for about 10. (And string inverters for 18 years) Optimizers have had a much higher failure rate than micro inverters in my experience and early solar edge inverters have terrible reliability. Bypass diodes on modern solar panels mitigate shading issues in a properly designed system. Cost savings with a modern string inverter is huge and a couple extra solar panels is way cheaper than optimizers or micro inverters.
Thanks for your input. I have had the opposite experience, but that just highlights that an installer with a good labor warranty who will be around is key! Also, the little bit that optimizers improve production is worth the money here (I did the math in another response) and most of my customers don't have room to add any panels.
@@bradthesolarguy 'Optimisers' don't improve production. Do you have any REAL WORLD proof that they do? 'Optimisers' are a con. They don't work.
Totally incorrect regarding string inverters. Most panels from the last five years have bypass diodes. Some are even half or tri-cut.
So, while shading a single panel, you will only lose power on that panel, or even a portion of it if it is half cut or tri-cut.
And in high heat zones, optimizers or microinverters fail every few years, if manufacturers go out of business, you must find the identical optimizer or microinverter to ensure that the system functions properly. But string inverters can be replaced with any manufacturer's product.
The main current disadvantage of string inverters is that you cannot monitor panels individually, however manufacturers like as Huawei are working on solutions for that as well.
Pretty sure it's EVERY panel from the last >20 years. Without bypass diodes shade could cause a fire. So not really optional. Shade doesn't kill strings if they're run independently Can't believe a self professed 'solar guy' wouldn't now this.
That’s just totally incorrect.
Please see my pinned response above.
~20 years is correct. I have 20-year-old residential panels which have bypass diodes. The "fire" part is not correct. A broken or shaded sub-string in a solar panel just blocks some of the current. No fire. Just less current (which the bypass diode, when present, fixes, by allow current from the other panels to bypass the shaded panel).
Any modern-day panel over roughly 200W will have bypass diodes. Tiny little panels like 25W, 50W, 75W, and probably many 100W panels generally don't bother. Larger panels always have bypass diodes these days.
@@junkerzn7312 I learned the importance of bypass diodes the hard way. I built my first array from laminates that didn't have diodes and I wasn't smart enough to install them. In the evening 1 cell was shaded in a string of ~8 panels. That was cell quickly heated up to >200F since >600w was dumped into a 5" x 5" silicon wafer. Pretty sure it would have melted and could have caught fire if I didn't open the circuit.
Interesting vid. I just had a system installed and elected to go with Enphase Microinverters vs. SolarEdge DC optimizers because I repeatedly heard of disastrous quality issues with SolarEdge and the difficulty in getting warranty service. Every Solar installer I spoke to in NH said the same thing except one who said they had turned it around. I was unwilling to test that out and went with Enphase. Only dissapointment is clipping which seems to keep me from getting mkre watts - is that an issue with SolarEdge as well?
Clipping is an issue on either system. I think SolarEdge does a better job with minimizing it, but it really depends on your enphase setup as to how bad it is.
so why do you have to put the optimizers or microinverter at the panel? why not run the cable to a central point that you can access any time?
There's a tradeoff between safety and cost. String inverters require rapid shutdown capability to meet the newer NEC requirements and prevent the fire department from letting your house burn down if there's a fire (because you cannot turn off the sun, so the panels are always "hot"). Microinverters will turn off the AC output when you switch off the AC circuit they are connected to (generally, you have to include and exterior solar AC disconnect switch). The newer NEC versions require that there is not active electrical output (AC or DC) outside the boundaries of the panel array when the system is disconnected.
@@surferdudemi i understand that but when your house is on fire no one is worried about turning off the power. first thought is putting it out and saving what you can if you can.
@@hayzersolar Then you should be sure that you can throw an external disconnect so that you can safely extinguish the fire, and the fire department can do likewise.
This is why Enphase and SolarEdge are the Coke and Pepsi of residential solar inverters. They have rapid shutdown and arc control at the panel level built into their technology.
@@bradthesolarguy That only works if the microinverters can see the AC line drop. If you have them connected to the AC load side of a hybrid inverter with battery backup, the microinverters will not see the AC line drop and will not turn off. You need two disconnects: one on the AC line from the grid, and another on the AC line from the inverters to the load side.
Your video was very informative, you obviously know your solar systems. We are retired and live in the UK and we had a 10 panel system installed less than 2 years ago. It was fine at first then the inverter (Solis) started sending alarms which all stated that there was an arc fault which should be dealt with and these have got more frequent lately. The installers came back once and said they found a faulty connecter under one panel and fixed it but the problem persists so I think that more connectors must be faulty. They want to charge me a lot to come back and fix these so I am waiting for another installer to look at the system. I suspect that these connecters are faulty or have not been correctly wired so my question is - is this a common fault with roof panels or do you think we have just been unlucky? I would appreciate your expert opinion on this.
Hi there. Tough situation. Warranties that have good labor coverage by a company that will be around to service it are a must when owning solar if available in your area. Unlucky that you don't have that. You are not alone unfortunately. Not surprising to me that the solar company wants to charge a lot because legitimately electricians are really expensive. They may be gouging you, but you might be surprised by their costs as well. You will know a lot more after the other quote. Could have been faulty installation work, or faulty equipment or both. Electrical stuff can be finicky. My only advice at this point would be to hire the person/company that you trust the most to communicate with you clearly and do the job well. Hope this helps!
@@bradthesolarguy Thanks Brad.
I respect most of what you're putting out here but the claim that optimizers have lower failure rates than microonverters runs counter to basically all industry data on the actual failure rates of these rooftop products. Do you have data on a specific optimizer showing long lifespans on them?
Not aware of any residential solar industry data on this topic that I would consider reliable. Mind sharing your sources? I'm genuinely curious. My opinion is based largely on two things. First, I've seen hundreds of systems and have almost never seen an Enphase system that didn't have a bunch of failures and don't think I've ever seen an optimizer failure. Second, inverters are doing the hard job of transforming electricity from one form to another and therefore wear out. Because optimizers are doing a much simpler job I think they have a lower failure rate. That being said, I'm very open to the idea that the micros are as reliable as optimizers. That would be great news for millions of people. But even if that is true, I would still choose a central inverter, which DC optimized system are, over micro-inverters because with micros you have AC coming off the roof and that is a huge problem for combining batteries with the system. It's possible to have an AC coupled battery system (many do!) but it has real and obvious disadvantages to a DC coupled system.
Please Referance Sources Please!
I too disagree, I think Enphase micro inverters are the best,work better in shading hands down,more efficient in the conversion, I would rather have ac coming off my roof, than high voltage dc,much safer.Now as for coupling with batteries you are correct, dc to dc is easier,and your not reconverting,but which one is being used most,already converted ac main power or recoveries dc to dc power. As for micro failures,most I see failing is miss matched panels to wrong micro, ie, 400+w panel into a micro inverter that's only rated for 285 to 305w. Personally I've ran mine for 7+ yrs and Ive had no failures on my complete system. My only regret is not having the IQ 8s when I bought mine, there the only system grid tied that can island themselves in grid down without battery backup,and that my friend is a lot JM2C
Enphase is a good product for shade control. SolarEdge is just as good or a little better for shade control and has DC coupling for batteries. And yes! So many system with too small micro-inverters! Yikes. Paid for all that wattage on the roof and can't access a huge chunk! Bummer.
At least in my area N. California the discrete panel minoring is disabled to the consumer. I think the main reason is to cut down on service calls. People that don't understand the system would be calling their installer right and left when they saw something they think is a problem when it's not.
Interesting. One would at least hope then that the system does log that information and send it to the installer, so if you do have a panel out, they can address that. The cynical view would be that they wouldn't address that at all if the consumer wasn't aware of it.
That is unlikely to have anything to do with your location and everything to do with your installer or lease holder and equipment. The solar company can turn on different views for the homeowner. You should ask them.
Well Said I can't even imagine HOW a micro inverter is going to be replaced say in the middle of the array
Just takes more time and expertise.
Thanks for this. A bit late for me, since my system was installed six years ago, but still enlightening.
I don't know if the DC optimizer was even an option back then. But I have found that the microinverters on my system are _incredibly_ *unreliable*. In six years, five have failed so far. There are only 20 to start with, so that's a 25% failure rate in just the first six years, averaging one failure per year. And of course, they are way up on the roof, where it's hard to replace.
Fortunately, the installer has been gracious about the whole thing. The inverters are under warranty, but the manufacturer doesn't cover labor. I had to pay labor for the first two repairs, but the installer has agreed to cover labor as these continue to fail, given how unreliable they have been.
Who knows if I'll still be in this same house if and when the panels have degraded enough to require replacement, but seems that already, and probably even more so by then, the technology has been advancing quickly. If it weren't for the cost, I'd love to upgrade my 300W panels with 400W ones, and switch to the DC optimizer approach you suggest here.
Thanks for sharing. Lesson is the installer is the most important choice!
As long as you have enough space on your roof, it's not going to be worth it to remove the old panels, just add more panels if your system produces insufficient power. Either expand on the microinverter system or add a separate string with inverter. With modern panels you can just use a string inverter and even optimizers are not worth the extra money.
The question some of us would have are, have the microinverter manufacturers learn and adapted from the early failures and now make them more robust and reliable than before, or his this still an issue years later.
One would also think like anything else, there are probably micro inverter models and brands that are far more reliable than other brands and models.
Optimizers are fine but increase cost just a tad over micro inverters. Secondly You'll have to replace the inverter aprox every 10 to 15 years on an optimizer system and the warranty is usually 10 years which means out of pocket for a new inverter. Another disadvantage is on a larger system you may need to or more converters which means more money when they fail. Those inverters are very expensive and fail due to the high heat and amount of wattage they are converting thus the reason for 10 year warranty. Micro inverters slightly more efficient , Warranty is 25 years, and according to installers I have spoken with extremely rare to have one fail. One installer that put in well over 200 systems says he had to replace two one which was bad from the get go the other failed in warranty and is a plug in connection. Now for charging a battery advantage does go to optimizers. They deal DC to DC with minimum loses though micro inverter systems even with the loses of converting is extremely low percentage.
SolarEdge and Enphase in the US form a virtual duopoly and their prices are negligibly different. That includes extending the SolarEdge warranty to 25 years. I agree that more converters or inverters are bad because they are more likely to fail. That is why I like Enphase slightly less. Optimizers are not doing the heavy work of inverting and are less likely to fail. 200 systems is not a very big sample size at all. More important than the specific equipment is the company servicing it by far! DC coupled batteries are clearly better in just about every way.
My experience is the opposite, DC optimizers seem to fail way more often then the micro inverters. I've yet to do an enohase replacement, but have run into many soleredge optimizers that failed.
With rapid shutdown rules, micros work really well.
Batteries, yeah that's marginally better, but it's a fairly minor percentage.
Appreciate your perspective.
What’s your recommendation on dc optimizers?
I think choosing an installer you trust to do good work and service the system for many years is your best bet. Let them advise on equipment. I like SolarEdge but go with what your installer recommends.
@@bradthesolarguy im asking because i do DIY solar and turbine projects, so i always take into consideration what other may recommend.
@@poransingh8420 Love that you are DIYing! Please don’t take my advice then. I’m not the right guy to advise on that then. Good luck!
Unless you have lots of shading, string inverters are fine, and what goes on the roof is simpler and more reliable. I have been using string inverters for years with no issues.
String inverters don't pass National Electrical code for modular level arc control and rapid shutdown. For this reason Enphase and SolarEdge are the Coke and Pepsi of inverters for residential solar.
@@bradthesolarguy Right now I use high voltage DC circuit breakers to short the string outputs which limits the current to an Isc of less than 12 Amps for a string. It effectively clamps all panel outputs to a few millivolts (non-zero due to resistance in the cabling). Works fine. If I worry about some arc damage to the switches on opening to restore normal operation, I can wait until the sun has gone down. The point is that a fireman could close all the breakers and then douse the panels safely, and they would be unlikely to touch the breakers again after they are done.
@@bradthesolarguylooking at doing a Powerwall 3 which is a string inverter and it says it meets NEC standards for rapid shutdown
Interesting. Thanks for the education. Are all microinverters the same? Are there no ones with added tech that voids the issues you talk about like this new one that comes with Anker Solix X1?
No. They are not all the same. There are several different micros from several companies and technology is always changing and advancing. What issue is it that you are hoping the Anker will solve?
@@bradthesolarguy was looking at getting the new Solix X1 inverter and thays where I heard about this microinverter stuff. Was hoping the Anker microinverter under the panels would solve the issue you mentioned about the whole system not working because of one panel since the microinverters each act independently. But now that you say they're not very reliable I might just go with the option you mentioned that's better than microinverters. I'm not a solar boffin and don't know the names and terminology so I hope I'm making sense.
Gotcha! My advice is to choose a good local installer who you trust to communicate clearly with you, do the job well and service the system for a long time. Let them advise on equipment. Why? Because you provably know people better than solar, so choose good people and take their advice. If they plan to be in business for a long time they will have planned how to service the systems and their equipment choices should reflect that. Hope this helps!
@@bradthesolarguy the problem is I live in a country with a very volatile environment, business and otherwise so businesses open and shut down like day and night. My first solar was done by my uncle in 2009 who ran a solar business then. Hybrid system. Did it perfectly. Four solar panels, sinewave inverter Chinese brand (sikui) or something along those lines. Still works today. 2021 got some company that came highly recommended by a family member. Worst mistake ever. Replaced the batteries, added a change over kit or box or whatever it's called. We went from an automated system that changes to solar when the mains go out to a manual system. Following morning woke up to the smell of burning plastic clearly coming from where the batteries are housed. Called him, he came over and checked and said everything was fine. Told him the system doesn't work as the 'battery empty' alarm comes on after a couple of seconds of turning the solar on at night or when cloudy. Long story short he had me change all the globes in the house at $5 per globe for what I later discovered were cheap Chinese globes. To this day the solar system does not work when the sun goes down. I paid almost a thousand dollars for that. It's hard for me to trust any of these solar people now so would rather learn everything myself.
Agree Microinverters does not make sense on when solar panels are in the roof, but if solar panels are in place that is more accessible, it make sense.
Yes it does.
Agree with Niall, you lost me when you mentioned about christmas light effect. There are plenty of videos showing actual tests , showing bypass diodes do a lot of the work to bypass the panels which are shaded. Sure microinverters /optimisers may give better/optimal output but these generally only make 3-5% difference, yet cost is around 10-20% more, not to mention, as you say, you may have more maintenance over the long run replacing the microinverters/optimisers.
Please see my reply to Niall as it applies to this questions as well. I am not a fan or micro-inverters. Your point about the cost is a good one. Let's do some math! If my 10 kw system lost 5% a year to shade that would be 500 kwhs a year. That's $200 at last years' utility rates here in Massachusetts. Let's say that stays the same for 25 years (no chance in reality of it not going way up) then that adds up to $5,000 worth (probably a lot more) of utility electricity I'm buying even though I have solar. That's more than 5 x the "savings" I would get from going with a cheap string inverter. I'll stick with my Solaredge inverter which combines the advantages of both a string and micro-inverter while hugely reducing or eliminating all the flaws.
You can get optimizers for around 500 bucks for 8. That’s pennies compared to the overall system cost (assuming a larger 3 kW system)
@@freddurstedgebono6029 that is useful info, though working the math it still doesn't seem economic. Assuming one big 500 W panel per optimizer and 5% improvement in yield (both generous assumptions) you get 25 W for $62.50 ... $2.50/W, not as bad as the first panel I got in the '90s (20 W for $200) but not comparable to current prices for just adding more panels (my last purchase was 455 W/ $315 CAD delivered). Even including mounting and install it would make more sense to add panels if you have the room.
Of course residential rooftop installs need an RSD to be compliant so that makes the optimizer a reasonable solution but that wasn't the original argument (also not all installs are roof mount). I'd recommend everyone do the math for their own particulars before making decisions.
It really has nothing to do with the cost of the goods. It has to do with the cost to have them installed and maintained. People should compare quotes not do their own math. That would be useless, so I get why you are recommending that.
In the US, if you are roof mounting, either DC optimizers or micro-inverter are absolutely required under every panel for the emergency shutoff feature. Simply stringing the panels is not an option and the whole shading problem therefore disappears.
Not quite. But yes you do need some type of modular level electronics for emergency shut off so might as well use optimizers!
I’m aware of the existence of shutoff only electronics, but the price difference of ones that also include optimization is so small, I’m amazed it’s profitable to design, manufacture, and inventory both flavors. Agreed from the consumer side, might at well use optimizers, and the whole shading issue disappears.
@@TexacateI agree!
Optimizers have a higher failure rate than microinverters. You’ll have just as much repairs or more from putting them under each panel. Most modern panels and string inverters don’t have the Christmas tree effect that systems did. That’s why Tesla solar systems are able to perform well without optimizers. Not as well as micro inverters, but significantly better reliability and lower cost.
Nope.
You nailed it. I studied all the options and the Powerwall 3 with six MPPT wide voltage range DC inputs beats everything. It's all in one box, less things to connect, you can segment to handle shading, less stuff on the roof. My buddy has four and they work great.
Why would anyone put sensitive electronics under panels (especially roof panels) that bake in the sun? And why would you want to deal with repeated trips up on your roof - if you've got tile/slate, the last thing you want is uncaring solar schlubs stomping around breaking tiles. My neighbor had a major roof leak soon after his solar guys came and added some panels. But since it wasn't at the panels themselves, the solar company refused to fix the problem. But it was the access way to the panels that were damaged - nobody else had been on the roof in a few years (it was only a few years old) - multiple tiles were cracked/broken and had punctured the roof sheathing. Cost him a few thousand to fix everything - he had to eat it since he redused to file an insurance claim and see his premiums rise.
In the US module level electronics are required to prevent arcing and to have rapid shutdown.
They are made to be outside under the panels. They are sealed and only require passive cooling. The fact that they are under the panels means they are not baking in the sun.
Unfortunately a lot of misinformation and confusion surrounds this. Best to check exactly what is the best for your own set, consider: type of panel (split cell etc), shading at various times of the day, ease of access, etc.
Sure. But really just choose a good company who is going to do a great job, and take care of you over time.
Well your video was a good video but you did not mention any DIY systems. I did my complete system myself at my farm. I had a nice unusable hillside that was facing the correct direction for a perfect ground mount. I went with Enphase inverters. My power company allows me to associate other meters with my net metering solar array so I don’t really use a lot of kW’s at my farm but I am able to apply the excess to my home bill. The total installation was somewhat labor intensive but so simple. The money I saved was tremendous. My system will pay for itself in 9 years.
Thanks! I don’t focus on DIY because it’s such a small percentage of people who can do what you did! Amazing. Love your story. And now you have the skills to maintain it and are saving tons of money. So great!
Can Tesla inverters have optimizers?
To my knowledge their technology does NOT include DC opimizers. I could be wrong. I'm not an expert on their solar equipment because I've never represented them. My customers for some reason demand customer service.
A Tigo optimizer system can be used
An advertisement of optimisers. He started by saying string inverters are bad and then moved to inverters and optimisers and then started pouring shit on microinverters. The reality is that optimisers will need a string inverter anyway. Todays solar panels have bypass diods so that the story of one shaded panel ruining the whole string is a BS. I doubt that today optimisers will be needed at all and pay for itself as for the money of optimiser you can buy an additional panel. The solar industry is a wild market where solar installers selling unnecessary devices for unfamiliar people. What customer need is a H-Bridge block which converts DC to a square AC and most of the appliances which using inverters will work without anything else. Who can justify why today we need sine wave AC in the houses where most of the appliances in fact have no need for this?
Again, because of code most solar companies in the US use either Enphase or SolarEdge. Between the two I prefer the SolarEdge system because it acts more like a string inverter. They are both good systems. And there are many other good choices too. But the most important choice is not the technology but making sure the installer will service the system over time.
4 parts to every system panels contoler (you left that out) storage batteries and inverter ... and to obtain efficency first storage then controler .. panels and inverters are least important and don't dump in to the grid. Keep the energy and bank ..never use a all in one contoler and inverter
Not everyone gets batteries with their system, he's just talking about solar here. Battery is an added expense. Might be a wise one, depending on your budget and where you live, but it's not necessary in order to have a working solar system and doesn't always make sense for everyone.
Yup.
Totally wrong, string inverters works totally fine, there is no "Christmas light effekt".
All modern panels has by-pass diodes, so this is not a issue.
What planet have you been on the last decade?
I’ve answered this many times in the comments. We are just going to have to disagree.
What he is saying is that when a string inverter stops working, the whole system stops working, much like one xmas light bulb burning out, causing the whole xmas light string to stop working. String inverters work fine, like you said, until they stop working. Then your whole system stops working.
@@bradthesolarguy LOL. "We are just going to have to disagree." Which means "I'm just going to keep pretending that bypass diodes don't exist, and mislead people with my obviously FALSE 'christmas tree' diagram." Laughable.
@@jeremycrisp4488 No, he says that if one panel is in shade, all the other panels in that string stop working. This is patently untrue, it's a LIE.
Brad says electronics that get through the first year have a full reliable life.
Quality Electronics last for decades.
Enphase has a good reputation.
If a PV panel or microinverter fails, you know which one and so can plan to replace it, no searching the array on the roof with enphase.
Timely action in warranty period.
Generation is maintained.
CASH SAVINGS is maintained.
Grid electricity is expensive electricity.
If the supplier disappears in the future, you probably will not need them if your system is reliable and older than one year.
240vAC microinverters on a metal roof is a safer situation vs 600vDC.
CASH SAVINGS lost adds to COST of cheaper string inverters.
This is misleading. Micros have 25 years of warranty (Enphase) and even if one would fail the rest of the system works great. With an optimizer based systems (Solaredge) both the optimizer and the inverter may fail. And string inverters only have a 10-15 years warranty. In addition, you are running high voltage DC cables on the roof with an optimizer type of system. Micros are a bit more expensive but they give you the piece of mind that your whole system will never fail. It’s AC and it’s safer due to no arching issues. And if you ever want to add panels in a micro system you just slap new panels on with new micros. However, with an optimizer based system you have to resize and buy a new inverter that match the additional panels. If one doesn’t go with Enphase then the Tesla Powerwall 3 with included inverter is the best option. There is no need for optimizers anyways as new solar panels have bypass diods in built that manage shading. Thus optimizer based systems have lost most of their historical advantages.
It's not misleading I just disagree with you. Both Enphase and Solaredge satisfy the Federal mandate for panel level rapid shutdown and arc control. This is the main reason they have a virtual duoplopy for residential inverters here in the US. I recommend extending the Solaredge warranty to 25 years. It costs about $300. Plus the Enphase system has a combiner box which when it fails knocks out the whole system. Solaredge has DC coupled batteries which are much better than what you can do with Enphase. No you can't just slap a few more panels on with Enphase at all! Most places here in the US that means an equal amount of paperwork as the original install. Permits, Interconnection, fire code, structural etc. In the real world though if you own your system I think you are likely to have more solar up time with SolarEdge than Enphase. This is highly influenced by the installation company as ultimately how things are repaired overtime will come down to them. Are they in business? Are they willing to eat the crappy money the warranties (both Solaredge and Enphase) pay for service calls and replacing parts? When a couple micros go out are they going to fix them or are they going to wait for 5 or 10 to go out to make rolling trucks worth it? Please note this all pertains to owning your own system. Warranties are not an issue with leases.
@@bradthesolarguy Well you can disagree but talk to installers and they all say there are much more quality issues with Solaredge than Enphase. And yes, you can just slap more panels and micros on if you want to enlarge your system. With Solaredge you have to buy a completely new expensive inverter. The permit times are irrelevant to that fact. There will be no optimizer in the future as they provide no real advantage to new solar panels dealing inherently with panel shading (diode bypass). Solaredge is most likely even bankrupt in a few years so that warranty goes poof. Check their company performance and losses so you understand.
@@TurreTuntematon I have over 1000 installed customers who were installed by installers that I have talked to. Maybe you should talk to somebody?
@@bradthesolarguy It’s well known among installers that the quality of Solaredge is not on the same level as Enphase. And not even talking about the warranty and customer service. Maybe you should take up your head from the sand before Solaredge goes bankrupt and you and your installer buddies along with that? Warranty says poof!
Can’t really hear you with all that sand in your mouth. There are many people, maybe more, who agree with me. And I happen to know and respect some of those people as I have worked with them for years. Do you have anything other than internet experience?
Makes a whole lot of sense my hillbilly friend.
Indeed it does!
@@bradthesolarguy No, it doesn't, because you're LYING about the 'christmas tree' analogy. Completely ignoring bypass diodes. Pure misinformation.
Not at all like a string of Christmas lights. Modern string inverters have multiple MPPT inputs, often four or six. So you have six strings of lights. The MPPT voltage range is often very wide, 60V up to 400Volts. So long it is possible to shade several panels in a string and still get the full power from the other panels so long as the illuminated panels are above the minimum MPPT voltage. It's time to stop telling the same old misleading Christmas light story. It's not 1980.
It's true that technology has improved, but the Christmas light analogy is still a good way to illustrate how they can be affected by shading. Also, string inverters do out pass code in the US.
I prefer a string inverter system - less to go wrong, much cheaper, and in most use cases, any differential panel shading only occurs at the start or end of the day, when not much power is available anyway. Secondly I would go with a hybrid inverter with build in solar chargers, such as EG4 18K or 12k which supports back-feeding the grid as well as power-shifting. These systems need to be used with batteries. I also like the EG4 LFP 48V nominal batteries - at around $1100 per 5KWh, they are a good deal, and should last decades if the daily discharge depth cycle is limited to less than 50% on average.
Sol-ark 15k is far better and you do not have to have a battery. The customer support is far better then EG4. You don't buy lithium just to use only half of it's capabilities You might as well go with a lead acid battery then you would only use that 50%. Lithium you can go from 100 to 0% You still going to get 15 years out of it but decades no, you're not getting decades out of any lithium battery just because you only using half of it
@@TheFatman819 Possibly, although the EG4 units are also reliable. A Sol-ark is much more expensive than the EG4 units.
Cycle life of LFP batteries is a combination of calendar aging and cycle aging. If a battery is rated at 7000 full cycles, it means that discharging to 50% each day it should last about 14000 days or 38 years. That well exceeds the calendar aging limit of 15+ years according to the manufacturer. What ages batteries is SOCs below 10% and above 95%, charging temperatures below 50F and above 100F, and charge rates above 0.5C (i.e. 50Amps for 100Ah batteries). I keep our batteries between 60F and 75F over all seasons. I use more batteries to reduce charge rates to < 0.2C, and also deal with cloudy periods in Winter.
The string inverter will fail around year 12, but microinverters last 30. Price that into your system choice.
@@TheFatman819Why is sol ark far better?
They have 50 year old panels making ~60% of rated power.....degradation is no worry are panels will be so cheap soon (see Rethinx) that it will be almost nothing to do so.
Agreed.
the trace inverter that runs my off grid house is in its 28th year.
That’s awesome!
Solar installers in FL have a worse reputation than used car dealers, for good reason. My GF solar edge solar inverter was toast in 4 years then the installer wanted $400 just to show up and "diagnose" the issue even though they already knew it was fried from the web connection.
Ugh! Sorry to heat that.
Deye hybrid inverter solve the problem with storage of energy in the battery because of the generatorport.
My oldest micro inverter is 22 years old.
If you don't buy a Chinese micro inverter it will last forever.
That’s awesome. Not going to be like that for most people though.
I'm in the middle of evaluating quotes for a roof solar installation and your comparison of microinverters vs optimizers can't come at a better time. Thank you!
Glad to hear it. Please remember I think the installer and their ability to service the system I think is more important than the technology. Hope that makes sense.
Check his advice; it's not complete at best. Do your own homework; look at DIY Solar Power with Will Prowse here on UA-cam. He's a bit all over the place but his information is dead accurate. With optimizers, you still need a DC-to-DC converter to normalize the voltage for either supplying to the grid or putting it into a battery. And if you're going to install batteries, you might as well buy one and cry once and put in a proper Victron or EG4 system. Once you price all that in, you'll figure out why a lot of focus opt for a solid solar company with SLAs on warranty work and micro-inverters. Let their guys and gals climb onto your roof.
Or do whatever you want, I don't care, it's your money and headache later.
Yes, what better time than when some poor sod like you, who doesn't know all the ins and outs of solar, asks for advice, and gets lies from a LIAR, who pretends that bypass diodes don't exist. Bad advice is worse than no advice.
Sounds like you haven't heard of bypass diodes ... most modern panels have 3 so this all 'Christmas light syndrome' really is more myth than fact.
@@niallparker3655 In residential solar there are three choices of inverter types from major manufacturers. In the US micro inverters made by Enphase have a huge market share and have all the issues I point out in the video. This is the reality of the marketplace. Are you saying that everyone should just use string inverters? That’s not what’s happening.
@@bradthesolarguy I do think most people would be better served by string inverters, many you tubers have videos on the minimal benefit provided by either micro-inverters or optimizers, certainly not economic and only useful in a few edge cases. Check out what others have found or better yet try a few experiments yourself before you parrot the marketing from Enphase and their ilk ...
@@niallparker3655 Not parroting anybody. I'm using my knowledge and experience of being in solar for 10 years. Are you parroting someone? I'm talking about the actual residential solar market in the US where, right or wrong, almost all companies are installing a non-string inverter on every job. That means half or more of those jobs use micro-inverters which I recommend against. I have no problem with people using a string inverter if conditions merit. Conditions in New England usually do not.
@@bradthesolarguy sounding a little defensive there mate ! ... ;) ... I guess if it isn't your own research then likely we both are parroting to a degree. I agree residential seems to be mostly non-string inverters but the reasons seem more marketing than technical. My issue with your video is that you seem oblivious to the actual performance of a shaded string with bypass diodes and unaware of multiple people demonstrating that these simple strings (no DC optimizer) do perform OK and are simpler/cheaper. Given you are marketing yourself as an expert in solar, seems worthwhile you educate yourself further, maybe try a few tests in your local environment and quantify how bad a simple string really is.
Umm, I may sound defensive because you said I was parroting marketing speak from Enphase and their ilk, which was not only wrong it was insulting. Thank you for agreeing that residential solar is mostly non- string inverters as that is the fact. Not oblivious to anything you are saying, but my goal is to provide useful information not academic. Truth is that, in the real world, solar installers aren't using string inverters for residential use. Further, where I live shade caused by trees, hills and mountains, snow and clouds affect every system. Because these systems will last decades a small percentage gain in production is well worth some additional up front cost. With leases or PPA's, the equipment has to be pre-approved by the lease company. Keep in mind the lease company makes their money by maximizing production versus installation and maintenance costs over 25 years. I don't know of any residential lease or PPA providers who have approved string inverters for residential solar in the Northeast of the United Sates. Wonder why that is?
No mention of this but don't string inverter systems have extremely high voltage on the roof and in Australia has resulted in many house fires ?
Don’t know about Australian electrical code but in the US you can’t install anything that will have high voltage resulting in fires!
@@bradthesolarguy In a string inverter system, solar panels are connected in "strings" of 6-16 modules, and the power then flows through the string inverter. The voltage of a single module is around 40-50 V, but when 20-30 modules are connected in series, the DC voltage of the entire system can reach 1,000-1,500 V. This high-voltage DC current then runs across the roof...any arcing can cause fire or death to anyone nearby.
@@benjamart AS/NZS4777.1 covers this and limits residential DC voltage to 600V. Please think before spreading FUD.
What about bi-facial PV panels?
Good for some applications.
Aren't batteries a crucial component?
Only if you are not connected to the grid. Otherwise, in most cases not at all necessary. I think of solar as a less expensive alternative to grid electricity and a battery system as a luxury you pay for. Of course, this all depends on how good the local net metering policy is too!
@@bradthesolarguy I guess maybe that depends on where you live and whether or not net metering is available? In Germany where I'm writing from there is no net metering. I pay much more for electricity I buy than for what I get fro electricity I sell ( 4 or 5 times more). And a lot of our usage is before or after peak solar generation hours. With a 10 kWh battery, we use virtually zero grid energy between April and September because of the buffer the battery affords. It is a different story in the winter of course. Having a heat pump with a hot water storage tank also helps (it effectively acts as another 'battery' heating water when there is a lot of sun and keeping it hot enough to use in the evening and when there is no sun)
Yes. Thanks for sharing. The net metering policy of your utility makes a big difference in whether batteries only used for back up power or if used to move solar electricity from day to night.
Really? You may have experience as an electrician but that doesn't mean you know what you're talking about.
What’s that now?
OK! This is a rather dumb slant on what is probably intrinsically poor product design from certain vendors.
Yes, Micro-inverters can fail if they are not used inside the specified range of current and voltage in/out.
Yes, DC optimizers can fail if they are not used inside the specified range of current and voltage in/out.
The bottom line is that BOTH of these devices are actually electronic switch-mode inverters. And BOTH can and will fail if used beyond their claimed ratings.
The input from solar panels to the DC optimizer or micro-inverter is the same. The OUTPUTS are not. And there are minor differences in the way such systems can be wired.
The main advantage of the DC optimizer over Micro-inverter is greater simplicity. Because it is basically a tried and true DC-DC buck-boost switch-mode technology coupled with MPPT input load optimization to "sum energy" into a common bus back to the actual DC - AC inverter powering your home.
The more common topology is to use DC optimizers under solar panels to directly charge a local battery storage system. This is cheaper, more efficient and more reliable overall. The DC-AC inverter to power your home then is from the battery only.
Some readers may find this helpful...
www.mysolarquotes.co.nz/blog/how-solar-power-works/micro-inverters-vs-string-inverters-a-comprehensive-guide/#:~:text=The%20power%20rating%20of%20a,of%20235%2D440%2B%20W.
Thanks for your take. Appreciate it.
The whole point of micro inverters is to minimize wiring and eliminate routing dangerous levels of DC on the roof.
I totally disagree. The US and the state of Massachusetts where I live, have strict code and permitting processes in place to make sure solar is safe. No one is routing any dangerous electricity across anywhere when following code, the UL listed manufacturers installation guides and passing inspection among many other safety requirements ALL of which are required before you can turn the system on. What you’re saying is dangerous, not DC electricity.
This is ass-hat advice. As you said, everything breaks. If a single micro-inverter goes down, you still have solar production until the crew comes out to replace that micro-inverter. I have Enphase on my roof and have had two failures in the four years our system has been online, and both of those failures were in the first 90 days. Also, you said something categorically incorrect. The solar panels don't just pour into the batteries. That's a fast way to kill your batteries because they can't handle the input voltage. You have to use a DC-to-DC charger.
So your failures were within the first year? Checks out with what he was saying. I agree with you that the solar panel to battery isn't a direct wire connection. He was noting that with micro-inverters you have to have a an AC-DC converter before the battery can receive the juice (charge controller not withstanding) and then you have to use a DC-AC inverter like any other battery system or non-microinverter system to use the power. I believe he left out the nuance of battery charging because it was outside the scope of what he wanted to cover in the video which was the many types of Solar Panels not battery charging systems.
Let’s keep it civil. Just because I have more experience than you do and think your wrong doesn’t mean I’m going to call you an asshat 😀
@@bradthesolarguy lol ok
Why does black on black matter?
It is only about how it looks. Without the black back sheet you see the grid design and a bluish color usually in the panels. The black on black panels look a lot better!
It's not only looks, even though the differences are incredibly minor the same panel with a white back sheet will run ever so slightly cooler and very slightly absorb more light.
Usually any line of panels that are available in bothe white and black backsheet configurations there is usually a 2-4% increase in the performance of the white back sheet versions. Since it's so small most people don't care and would rather the nicer looking full black panel.
@@Snerdles Correct. But don’t get confused. A 400 watt either way is the same. So the white back sheets make it slightly cheaper. Not enough to overcome the ugliness through!
You claim panels are "going to last decades". So sure, 21 years is "decades", but I assume most people understand that to mean "at least 30 years". Do you have any evidence that panels last 20+, 30+ years? I'm skeptical that there are enough 30-50 year old panels in service today to make any meaningful prediction about the life of current panels.
The industry standard is a 25 year manufacturers warranty. The technology has been in use for over 65 years. So there is tons of evidence they will last a long time.
Why would I install ANY expensive, critical devices that, as you say, are guaranteed to fail. DC, micro or otherwise? I have yet to see any ROI projections that include these costs. Solar as sold today is a fraud.
Inverting the electricity is a must for tit to run in your home. All solar includes this cost. ROI on solar depends on your situation with electricity rates, netmetering and your roof. The roi on my system is north of 15% annually for the first 8 years and that roi increases every year!
true, we all know furnaces and air conditioners never fail.
@@bradthesolarguy LoL You've dodged my comment's point. No ROI projections I have seen factor in the replacement cost of those "guaranteed to fail" inverters - DC string or AC mico. Without a accurate cost basis, such fake projections are misleading. If the failure rates of all types of inverters is as high as you say you know them to be, leaving out that cost is fraudulent. The same goes for any batteries that are expected to need replacement due to known issues.
@@kn4cc755 I do include them and recommend that all people going solar make sure they have a repair and maintenance plan in place!
@@kn4cc755 Not sure I follow your logic here. A 5kW solar array in my area is around $17,000 installed. A 5kW solar inverter is around $750 or so. If it fails every 10 years, we are talking about $75 a year in additional annual operating cost. A 5kW solar array in my area would generate roughly $1505 worth of electricity annually. If we factor in the inverter failure, it is producing $1430 worth of electricity annually.
So, the solar array would pay for itself in 11.3 years without the inverter failure, and in 11.9 years with the inverter being replaced every 10 years.
So, why would this shift of a few months make solar a fraud...? Not following the math here...
This is a blanket response to all those below saying I’m wrong about the Christmas tree analogy. To those screaming that it’s wrong and dangerously misleading to use this analogy because it no longer applies because of Bypass Diodes, please keep reading. The Christmas tree light analogy works perfectly in explaining how solar was traditionally wired and installed. Therefore, it is both useful and applicable. To say that it is not is like arguing that explaining how internal combustion engines work is no longer necessary.
Modular level electronics such as micro inverters or optimizers use technology to overcome that very problem. Understanding that basic issue will help consumers in understanding how solar works. Bypass Diodes are just a new form of a modular level electronics that helps overcome the shade problem. String inverters coupled with panels with bypass diodes may be just as good at controlling the shade as any other technology. That’s a moot point today here in the US where it’s not offered to residential consumers because of the virtual duopoly between Enphase and SolarEdge. Plus, if you just use a string inverter, you lose the advantage of modular level electronics that give you monitoring access at a panel level, which is super important to consumers. If you don’t have that, you won’t know if you have an individual panel out easily.
Also to be 100% clear the most important thing for a consumer to do is use an installer that they trust to do a good job and take care of the system for a long time with a good warranty that covers labor. That’s far more important than an individual technology choice you make. Hope this helps clear things up.
There's nothing new about bypass diodes. They've been standard in all solar panels probably since the first use of solar panels. The 'Christmas light effect' was never a thing with the exception of parallel strings. If one string is shaded in parallel with an unshaded string you can lose the unshaded portion of the shaded string. This is easily avoided by running each string to its own MPPT.