If you are in DFW, don't hesitate to reach out: 972 675 7725 ( call or text) or shoot me an email: info@solartimeusa.com If you are not, you can also reach out, I do solar consultations and quotes review all the time :) Leave some thoughts below! I try to respond to all comments! :)
With the price of 240V stand-alone Hybrid inverters being so inexpensive and fairly power efficient, there is no reason not to have two or three of them on the wall these days giving homeowners more than enough redundancy. I have three NHX 10kW inverters (125A capacity) that cost $6,600 total (yes, total) and idle at 75W each which I admit could be a little better. However, If an inverter goes down, I still have two of them that can provide 83A @ 240V. So there isn't a single point of failure. And they are so inexpensive relative to the overall system cost, I will be buying a spare here shortly. I also have a very inexpensive TIGO system for basic panel level monitoring which is all I need because I have no shading at all. This eliminates any real cons to string inverters and blows away microinverter setups on price by a huge margin. Not to mention DC coupled systems are more efficient. No clue why anyone would build a new AC coupled system in today's market.
Great video Martyna! I saw a new video just a couple weeks ago where a solar youtuber was talking in his video that same old line about how one shaded solar panel would kill the power from all the other solar panels on the string when that hasn't been true for about 10 years since they started installing bypass diodes inside solar panels that helps limit shading losses.
I have both a string inverter (2020) and micro inverters (2023). One of the strings had a chimney nearby so that pretty much killed the current for about 2 hours a day. Tigo optimizers were added to fix this, but did absolutely nothing so after battling with Tigo support for months I ditched them and had GNE Honeybee optimizers added instead. These do the trick. On the other roof I chose Enphase instead because of the space savings inside, more redundancy, better handling of shade which is a bigger problem there and the expected lifetime of these inverters as there is a 25 year warrant on them. The neigbours string inverter just died within 5 years and that really brings up cost in the long run if you only have 8 panels connected. If you have a lot of panels and shade is not an issue, a string inverter just makes more sense in terms of initial cost. I am considering installing two more panels on a shed myself and with a tree nearby shading one of those in the morning I think micro inverters will be the way to go, although I will choose another brand that is cheaper than Enphase. Another nice thing about micro inverters is that you are not limited to one type of panel per string and degradation of one panel will not affect the others in the long run.
You do great videos and I love watching them. I only have one comment: on the safety element, micro inverters will stop operating if the grid disappears (unless you do fancy stuffs). This effectively isolates each panel and you won't have energized wires on your roof. Strings of panels are always energized on the DC distribution. In case of fire, strings are certainly more problematic.
Excellent Video, you nailed it. We installed our Solar system in March 2011 with an over spec-ed SMA inverter in Perth Western Australia. It does get hot here in summer 40 deg C is not uncommon. We expanded the system in 2015 taking it to 4.4kw (Small I know but solar was expensive in 2011/15). We also added a 13.5kw battery in 2022 and now run our 4x bed 2x Bathroom home 92% of the time off solar or battery that is the 1yr average… so pretty good (That includes some EV charging). In that time we have not had a single failure of the system and we have 40x 110w Kaneka (Japanese) panels with no shading. So everything you said fits with our experience including the ability to expand a string system provided you over specify your inverter initially. Thanks for the video great advice. We will probably replace it in a few years time, most likely without a separate inverter just a hybrid Battery with a 10yr+ warranty.👍
eg. Fronius GEN24plus 10 kW hybrid, which I have had since 2022, has a dual pv1 input, a pv2 input and battery connection. You can connect SE and SW to different strings. Or for "winter" production, you could connect top row and bottom row to different strings, so that top row starts producing earlier. So with right choices even without microinventer you can reduce/manage/optimize the panel string impact and morning/evening/spring/autumn production. All with a single inverter. Fronius Gen24 online manual is excellent, I hope all brands would have similar.
Totally agree. I have a heavily shaded site and was hell bent on micro inverters. After a while once I got the quotes I found the cost around 10-20% more expensive. Have seen a number of videos comparing string vs opt/micro's(including yours) and they all seemed to have a best case scenario of around 5%, and given the extra cost upfront it is pretty hard to justify especially given potential maintenance effort down the track. So instead I am using the extra $$$ I would have spent with the micros and buying more panels. One other point is that not all string inverters are the same, as they have different algorithms to track the MPPT. From my research SMA and Fronius seem to be the best with handling shade which is what I plan to go with. I think these 2 inverters have a very good reputation and are less likely to fail. I have had an SMA on another property for almost 10 years now and it is still going strong.
I have a Growatt inverter from 2020. It jgets near to nothing if a sharp shade (chimney) hits just one panel. But if you have multiple strings and a lot more panels for the same price that may not really be an issue. I also have an Enphase system on the oppsite roof which is away from the sun most of the day. Oddly it outperforms the string inverter on any cloudy day on a per Wp calculation. The IQ8 series really makes the most of what the panels are getting in these conditions. In clear weather they also perform pretty well until the sun goes over the roof. My roof space is pretty limited so in hindsight I would have chosen a SolarEdge or Enphase system instead.
@@marcnerius9723 There are some better inverters and panels that can mitigate shade to a large extent. But every situation is different, so I would not take a chance unless adding some optimisers later was really easy and cheap to do.
Living in Northern Norway with 7 month of winter the problem isn't shading by trees but snow covering. Thats why I prefer micro inverters (APsystems with 2 or 4 independent channels). On the other side I don't like the idea of replacing a micro inverter in winter time. So it's not an easy decision.
@@solartimeusa I would like to test the difference of bifacial panels and usual panels next winter. Reflected light to the bakside (snow is an excellent reflector) would not only give a little more power but also warm up a snow covered panel faster. There is little experience how much faster the snow is smelting. At least we have no problems with overheated panels or micro inverters 😀
I'm thinking abt adding solar panel at my home in Manchester, UK which is 70% of the year is cloudy. I got few quotes & most wants me to put in MicroInverter. One installer suggested to use Aiko 455w Gen2 solar panel which got Partial Shading Optimisation in built it along with Sun Synk 5.32kw inverter & 2x5kwh Sun synk battery. With 16 panel he sugested it would generate abt 6200kwh annually. I'm really struggling with understanding various component and which to go for. Thanks for helping me ignore MicroInverters as I agree there are more cons with them then pro. I wonder if you have any suggestiong/opinion on setup I was proposed with Aiko Solar panel? I would really appreciate your thought on it. Thanks for great videos -really helped me in my journey in understaing this Solar world.
Martyna, what my thoughts are? Love your videos! You did not mention, Half-cut Solar cells! Isn't Half-cut Solar cells in Solar panels the main reason Micro inverters and Optimizers are basically obsolete, for all the reason you mention. I think new, Half-cut Solar Panels have twice the Diodes of older panels allowing shading to internally route around shaded parts of the Panel? Hope I said that right. I pulled this off Google AI. Yes, half-cut cell technology on solar panels significantly decreases shading problems by allowing the panel to produce power even when parts of it are shaded, as the cells are wired in smaller, independent sections, meaning a shaded area only impacts a smaller portion of the panel's overall output compared to a standard panel where shading on one cell can affect the entire row of cells. I have Panels on my Boat, Cabin and soon new house we are building. I have a waterproof design to cover a 14' X 40' Patio with only Bifacial Panels. The Panels will be installed without anyone on the roof!! Anyway, I thought if you were to mention the benefits of Half-cut technologies it could help drive home the point you are so wonderfully and accurately making.
I got around the string inverter 'single panel failure' issue by putting 4 separate strings (8 panels per string) in parallel to feed the inverter. Each 2.5KwH string is fed into (with proper fusing) the inverter so that if I lose a panel on any particular string, the other strings continue to feed the inverter at their full power level. This seems to (and has been) working great over the last 8 years. I wish I could monitor individual panels, but to date, it looks like everything is producing as expected. I built it this way because I have a high roof and I'm getting a little too old to climb it! 😀 +1 to Martyna for exposing the benefits of each.
Microinverters for my 35kW ground mount were far far less expensive than the multiple string inverters and easier for install. There are 2-in-1 or 4-in-1 microinverters which helps combine units, causing an overall reduction in "price per panel". You do get combined possible points of failure at that point, but they are relatively inexpensive to replace if they happen to not be covered under warranty.
Great video thanks. I have one question regarding the one point failure argument. By adding optimizer you do you recreate point of failure on the roof ? What happens when an optimizer (which i think less complicated than a micro-inverter) fail ?
Very good point! iF YOU DONT NEED optimizers I would not use them, but if you do, the difference of that point of failure is that that unit is an addition, its not a requirement. So if in 10 years Tigo is out of business ( hopefully not!), you can simply remove the optimizer and plug the panel into a string and it will keep working, whereas if you have a micro, the panel is useless unless the inverter is operational. I hope that makes sense?
Great video!!💪🏻 I have been thinking this a lot. I think the best approach is multiple lower capacity(4-6KW) string inverters in parallel. That way you can easily adjust solar panels as repair or upgrade. Also redundancy if one fails (I assume you would have to use the battery without close loop), you can keep going. I have also been thinking (if net metering is alive) to mix off-grid and a grid tied inverter in the setup, instead of going hybrid.
Hi Martyna. Thank you for putting your time and effort in real time efforts which help users like us gain a lot of insights. I am looking for a solar system for my home and I am considering enphase iq8p and sungrow string inverters as options. Cost is not an issue. The location chosen is one which does not have shadows for a radius of 10 meters. Would enphase be really producing more power than string inverter in such scenarios?
My thoughts?? HHMMMMM What would the difference be if the panels are over 100 feet from the house.. Wouldn't it be a better idea to increase the voltage to run the distance and reduce it at the house? Is that possible with micro's??
I agree that optimizers from a value standpoint are likely not worth it, plus add complexity, losses, and failure points... but per code, most roof mounted systems (which are the majority) require some type of RSD and I believe the optimizers with RSD built in is likely the cheapest way to meet code.
Great video! One thing you missed and maybe it's not an issue in TX, is rodents. At least 50% of people I know that have solar have had the wires chewed coming off the panels at least once in the last 10 years. One person resulted in a house fire and another with just the whole system off-line till they could get the replacement and company out there to fix it, both simple string inverters. All the rest have either optimizers or micro inverters with little issue but the one panel going down with only the low voltage from that panel not likely catching nesting material on fire. I happened twice to us, before we installed rodent guards around the perimeter of the arrays. My neighbors have brick facing and there's no way to stop squirrels from climbing right up. One of them has a PPA and the company keeps coming out to fix the issue and still haven't installed guards.
Is it possible that more string inverters are more popular because more people try building their own storage devices therefore wouldn't work with micro inverters or am i wrong
With string inverters is there a way to take advantage of the DC to charge Tesla EVs (approx 400VDC)? Currently charging with AC and the car has internally an AC to DC converter to charge the batteries. Thanks
Thank you @Solartimeusa Martyna for your insights! Would you be able to comment on with advantage of having string over micro inverters with battery ? do you suggest which would be better . Hope my q is clear .
When it comes to battery I suggest String HYbrid inverter such as Tesla POwerwall 3 or SOl-Ark. If you plan to add battery in the future, doing string will be an easier upgrade.
Did you mention that the highest DC voltage within the system is string voltage, for string inverters but only panel voltage in the case of micro-inverters? One’s house insurer may have some reservations about a potential 600V (or more) DC source within/without your home? AC is much safer, at mains voltages, than DC - for humans and fire risk. Edit: mrntioned, sort of, lower down but simply dismissed by some.
Microinverters offer more flexibility and future-proofing for your solar setup because solar panel models tend to get discontinued quickly. Microinverters allow each panel to work independently, so you can mix and match different panel types and specifications. This means you don't have to update all your panels if one model is discontinued, unlike string inverters where all panels need to be the same. Plus, microinverters make it easy to expand your system. If you want to add more panels later, you won't have to worry about compatibility issues, which can be a significant headache with string inverters. Also, consider this: the warranty for a panel usually involves replacing it with a similar unit, which almost never has the exact same specifications as the original. The warranty might cover labor costs for removing and installing the defective panel, but with string inverters, this mismatch can make panel warranties practically useless.
Great info! I would also add that the ability to DC couple batteries is so much more efficient. I believe that micro inverters paired with batteries is not the right solution as you are having to convert the electricity 3 times (at the panel to AC, when charging the batteries back to DC, and then back to AC when discharging the batteries). A system like the Tesla PW3 makes all of this a single step process depending on what the home needs. If the battery needs power, the panels feed the PW3 directly with DC power. If the battery is full, the power is simply inverted once and fed directly to the panel. Each time you are having to convert, you’re loosing about 3%.
Skeptical.... promises too many great things. paid a few RUclipsrs for sponsorships, but the company is young, if the industry will continue to be slow for the next few years, I do not see them sticking around. I would not put my own money in it. BUT I cannot say negative words about their systems, from what i saw, its pretty impressive, its warranty I am worried about.
ok lady you did a through breakdown of everything 🔥🔥🔥 i install string inverters because is cheaper for customer and not much different if roofs have full sun also because of the need of expensive ac coupled batteries, the difference in price is crazy.
You got a new subscriber with this video. (I wish your company serve KATY TX - becuase i am looking for a solar system for my house). Is the warranty of both systems the same? There is video indicating that the micro have lot more warranty than string systems. Is this correct?
I'm looking into installing panels and at least 1 battery this fall. The Mango Power M is my choice of battery, for the moment. The battery would be DC coupled. Because of the east-west orientation of the house and shading issues, I think DC power optimizers will be a must. Definitely don't want to go with micro inverters. The Power M can also be AC coupled, but I would rather have the efficiency of being DC coupled. Would like to get a quote from you, but I'm in NY. Thanks for all your informative videos and taking on microinverters vs optimizers a number of months ago.
After installing 800 systems, When designed and installed correctly, String inverters make more Power, Period. Complexity kills, Computers under panels make little sense in most installs.
THis was a relatively well done video. One thing that is missing from your benefits of Micro inverters is Arc Fault protection. AC Voltage with a 0V crossing helps stop and interrupt arc fault. DC wiring simply does not have that as an option. You somewhat got there with the balancing circuit but not quite.
I personally have a SMA sunny boys in my house and those units are extremely sensitive to arc faults and if there is any detection system, it turns off until an installer checks on it. So it has very sensitive arc fault detection.
I am planning to go solar my choice is solaredge inverter and LG battery 16.4 kw plus Canadian solar panels! What is your opinion about these choices? Thanks! From California
Thats a cool setup for sure! What were your other options? I am not a huge solar edge fan, but they have proven to be a very stable company and even though they had some issues in the past, they always come through with their warranty replacements. HOnestly, I probably like them best after SMA for their customer service. Good luck and I am so happy for you to go solar !
Hi Martyna , unfortunately I had that issue when 3 panels became shaded it would bring down the whole string and the second string . Panels have bypass diodes in them but would not activate . DC optimisers fixed the problem on the 3 panels . Soni would never rule them out.
I have a hypontech 4kw grid string inverter, Solar panel are green sun 250w mono panels 2022… .I had to turn that string off and turn it back on again straight away and that would fix the problem until I got DC optimisers and I didn't have to manually every day. I think if you shade three panels very slowly it doesn't activate the diodes but you would have to test this yourself on your setup. If you need any graphs from inverter I can send them on. Thanks Alan
Franklin is a AC coupled battery so it has a built in inverter. So you can use either option. The solar system will have its own inverter ( either micro or string) and the battery will in case of FRanklinhave its own inverter.
Despite the neighbors with their professionally installed pv systems using MI's I did a diy install and chose SMA. A year post installation and I am very happy with that decision. I did purchase the SMA 10 year extended warranty, inverter warrantied for 20 years, for only $350 with the Federal Tax Credit. If the inverter does fail in the next 10 to 15 years I will simply replace it. If the pv systems is down for a few days I dont care. hahaha I bank enough credits where it can be down for months. DIY allowed over paneling with the total cost being 1/3 that of professional installation quotes.
I'm convinced that string is the way to go but just have concerns with failure. When the inverter fails does it slowly ramp down or just burn out with no indication? If so, I would be without power for a long time until I can get a new one delivered and installed.
I do not understand what you are referring to as 'single point of failure'. That would be a potential to any system if the design did not adequately account for such things. Doesnt matter if it has batteries or not. A well designed battery backup system could still account for different failure scenarios. Perhaps you can be more specific with your question and context?
Here is my issue with string vs micro single point of failure. If I use a string inverter and it fails, my system is down. which sucks but is not then end of the world. but as i live in a remote area and the large string inverters have to be shipped via freight, when it does fail, I'm out the cost of the inverter AND 2000 dollars in shipping cost. if one or all of my micros fail, usps of ups or fedex can deliver a whole batch of them for under 200 dollars. Nobody ever includes shipping cost in that calculation.
Have you ever seen a DC arc fault fire - i know what i want on my roof with my family living below - micros also have up to 25 year warranties - this is not a fair comparison
Not once have I had a fire caused by an arc. Most modern strings have very very sensitive arc fault detection. Microinverters "come with a 25-year warranty" but in the majority of cases the main combiner is only on a 5-year warranty. So keep that cost in mind for the future.
@@solartimeusa there was a solar fire a couple of weeks ago on the swimming centre in Sydnry Australia on the pool centre used in the 2000 olympics - arc faults are real and DC strings are dangerous - enphase has circuit breakers for protection - why risk a fire on your home - they are up on the roof in the weather for a long time is my point
Doesn't Enphase require internet connection with a Enphase wifi box. That wifi box is only warrantied for 5 years. How long has Enphase been in business? Nowhere near 25 years. Whats the largest panels their MI support without clipping? Is it less expensive to over panel, increase pv system, with a string inverter or over panel with MI's where each panel requires an MI. ARC faults are the mc4 connectors, which Enphase uses, compatibility issues or installation issues. Those MI combiner boxes require a lot of connections increasing the chance of an arc fault.
@@ridemfast7625 theres no arc faults on an AC system as max voltage of 1 panel not 14 like a string - its called a short circuit an trips the breaker - strings cant be added to over here if the DC goes over 600v so maybe different rules there but enphase far easier to add to - string invertors only 5 year warrantys
Wait six months and get one of the new inverters with software that can switch the DC into smaller blocks creating a better AC sine wave. They are getting over 99% efficiency. While 95% to 99% may not sound like much, over a year, it adds up.
@@wazup3333 I cannot. This video goes into detail about resonance and soft switching. ruclips.net/video/pdyXEbWoVvE/видео.html. My understanding is that a few companies have proprietary software that can change the switching frequency within a single sine wave and maximize use of resonance in order to reduce losses. I just found this video which a stock pump for one of the companies but it has a good explanation ruclips.net/video/2JxbNi4lnUw/видео.html.
Ironically, optimizers and rapid shutdown devices have much higher failure rates than microinverters. You will spend much more time doing repairs on the roof with optimizers and rapid shutdown devices. Remember SnapRS?
For me, I've always recommended microinverters, because string Inverters are a single point of failure. If something goes wrong with a MicroInverter, it's $180-240 to replace that single inverter, whereas the String inverters, it's $2500~ for a replacement part. I will say though, your point about DC-DC battery coupling was 100% on the money. The future-proofed system for EV's is probably the system which gives the better DC access (String).
Thank you for sharing your thoughts. I agree that for different situations, different applications will be more beneficial :) Thank you for leaving a comment as well!
I would be reluctant to have 400-500 volts DC on a roof made of combustible material like asphalt shingles. 400 VDC is a far greater fire hazard than 240 VAC. For a rooftop installation where rapid shutdown is required, DC optimizers give you just as many points of failure as as micros. Where the current tech is, I would only consider string inverters for ground-mount systems. As for batteries being a single point of failure in a microinverter system, I don't see it. I can turn off my battery breaker with no effect on my system's production. Turning off power to the Envoy has no effect on production either; it just kills monitoring and reporting. Put a clamp meter on the branch circuit(s) to the array(s) and you can see they're still producing.
I think you forgot the aspect safety! one solar panel produce around 40volts, with only 12 panels a whopping 480 volts running from the roof cable towards the inverter, if this inverter is installed somewhere inside your house (not everyone has a garage) it can cause dangerous situations, with micro’s the power is inverted to 230/240 volts under the panel and stays the same with 1 panel or 50 panels toward the electrical cabinet.
I was wondering why I had not heard of micro inverters before, until I realized you are only talking about home fixed installations. Oops. I'm in the wrong place. All my research has been for mobile solar installations only. My brother in law installed a home solar system. He got taken for a ride, so much so that I had to lend him thousands of dollars. I will not make that mistake.
I have a string inverter (EG4 18k) waiting to be installed. Along with a EG4 Power Pro and 8 kw in panels. Ill be upgrading to double the battery size, and more panels (12 kw total?) next year sometime.
People frequently have the incorrect assumption that higher voltage is deadlier, that is only one part of the equation. Here is a simple explanation by Science ABC YT channel Current vs. Voltage: How much Cirrent can kill you? ruclips.net/video/y_cWTWB-N_I/видео.html
I'm an electrical engineer. Are you? I've used (tried to use) solar for the last 15 years. Things have changed dramatically in that time. In those 15 years solar proved to be a really bad idea (but I was forced to use it). Now it's a better idea. The cost of panels is 1/4th what I paid. The cost of inverters is 1/10th what I paid. And an inverter for each panel was impossible. Here's what it's about. A solar cell is a "current" source. You can put them in parallel but you can't put them in series unless they all produce the same current. After "inverting", a solar cell is a "voltage" source. You can put them in series but not in parallel. And with SMPS (switch mode power supplies) you can make myriad electrical sources work in parallel or series optimally... and in sync (like our power grid does). In a short time, you'll be able to replace inverters on panels like screwing in light bulbs. You have to have a way to clean panels off anyway. And like light bulbs, you'll likely never need to do it because they will last forever. The light bulb is a good metaphor. We went from arc lights to filament to fluorescent to compact fluorescent to LED string to screw-in LED to... who knows what's next. Right now, the engineering for solar is gen 3 (warmed over gen 1) ... and it's ridiculous. I hope you're an engineer and just trying to dumb this down for consumption.
Didn't watch the video. There's no debate, at least, not with me. When/If I ever get solar installed, I am absolutely NOT, doing the micro-inverters. It's just an extra piece of hardware, that can go bad. No thanks. I'll keep my system, as simple as possible.....and part of that goal, is minimizing the amount of hardware that has the potential to go bad on me.
If you are in DFW, don't hesitate to reach out: 972 675 7725 ( call or text) or shoot me an email: info@solartimeusa.com
If you are not, you can also reach out, I do solar consultations and quotes review all the time :)
Leave some thoughts below! I try to respond to all comments! :)
An honest channel. Ty for the work you do. Truly appreciated.
With the price of 240V stand-alone Hybrid inverters being so inexpensive and fairly power efficient, there is no reason not to have two or three of them on the wall these days giving homeowners more than enough redundancy. I have three NHX 10kW inverters (125A capacity) that cost $6,600 total (yes, total) and idle at 75W each which I admit could be a little better. However, If an inverter goes down, I still have two of them that can provide 83A @ 240V. So there isn't a single point of failure. And they are so inexpensive relative to the overall system cost, I will be buying a spare here shortly. I also have a very inexpensive TIGO system for basic panel level monitoring which is all I need because I have no shading at all. This eliminates any real cons to string inverters and blows away microinverter setups on price by a huge margin. Not to mention DC coupled systems are more efficient. No clue why anyone would build a new AC coupled system in today's market.
Great video Martyna! I saw a new video just a couple weeks ago where a solar youtuber was talking in his video that same old line about how one shaded solar panel would kill the power from all the other solar panels on the string when that hasn't been true for about 10 years since they started installing bypass diodes inside solar panels that helps limit shading losses.
so many people still believe it and repeat it...:( its so aggravating
I have both a string inverter (2020) and micro inverters (2023). One of the strings had a chimney nearby so that pretty much killed the current for about 2 hours a day. Tigo optimizers were added to fix this, but did absolutely nothing so after battling with Tigo support for months I ditched them and had GNE Honeybee optimizers added instead. These do the trick.
On the other roof I chose Enphase instead because of the space savings inside, more redundancy, better handling of shade which is a bigger problem there and the expected lifetime of these inverters as there is a 25 year warrant on them. The neigbours string inverter just died within 5 years and that really brings up cost in the long run if you only have 8 panels connected.
If you have a lot of panels and shade is not an issue, a string inverter just makes more sense in terms of initial cost.
I am considering installing two more panels on a shed myself and with a tree nearby shading one of those in the morning I think micro inverters will be the way to go, although I will choose another brand that is cheaper than Enphase.
Another nice thing about micro inverters is that you are not limited to one type of panel per string and degradation of one panel will not affect the others in the long run.
You do great videos and I love watching them. I only have one comment: on the safety element, micro inverters will stop operating if the grid disappears (unless you do fancy stuffs). This effectively isolates each panel and you won't have energized wires on your roof. Strings of panels are always energized on the DC distribution. In case of fire, strings are certainly more problematic.
Excellent Video, you nailed it. We installed our Solar system in March 2011 with an over spec-ed SMA inverter in Perth Western Australia. It does get hot here in summer 40 deg C is not uncommon. We expanded the system in 2015 taking it to 4.4kw (Small I know but solar was expensive in 2011/15). We also added a 13.5kw battery in 2022 and now run our 4x bed 2x Bathroom home 92% of the time off solar or battery that is the 1yr average… so pretty good (That includes some EV charging). In that time we have not had a single failure of the system and we have 40x 110w Kaneka (Japanese) panels with no shading. So everything you said fits with our experience including the ability to expand a string system provided you over specify your inverter initially. Thanks for the video great advice. We will probably replace it in a few years time, most likely without a separate inverter just a hybrid Battery with a 10yr+ warranty.👍
eg. Fronius GEN24plus 10 kW hybrid, which I have had since 2022, has a dual pv1 input, a pv2 input and battery connection. You can connect SE and SW to different strings. Or for "winter" production, you could connect top row and bottom row to different strings, so that top row starts producing earlier. So with right choices even without microinventer you can reduce/manage/optimize the panel string impact and morning/evening/spring/autumn production. All with a single inverter. Fronius Gen24 online manual is excellent, I hope all brands would have similar.
Totally agree. I have a heavily shaded site and was hell bent on micro inverters. After a while once I got the quotes I found the cost around 10-20% more expensive. Have seen a number of videos comparing string vs opt/micro's(including yours) and they all seemed to have a best case scenario of around 5%, and given the extra cost upfront it is pretty hard to justify especially given potential maintenance effort down the track. So instead I am using the extra $$$ I would have spent with the micros and buying more panels. One other point is that not all string inverters are the same, as they have different algorithms to track the MPPT. From my research SMA and Fronius seem to be the best with handling shade which is what I plan to go with. I think these 2 inverters have a very good reputation and are less likely to fail. I have had an SMA on another property for almost 10 years now and it is still going strong.
I have a Growatt inverter from 2020. It jgets near to nothing if a sharp shade (chimney) hits just one panel.
But if you have multiple strings and a lot more panels for the same price that may not really be an issue.
I also have an Enphase system on the oppsite roof which is away from the sun most of the day. Oddly it outperforms the string inverter on any cloudy day on a per Wp calculation. The IQ8 series really makes the most of what the panels are getting in these conditions. In clear weather they also perform pretty well until the sun goes over the roof.
My roof space is pretty limited so in hindsight I would have chosen a SolarEdge or Enphase system instead.
SMA also has built-in ShadeFix technology that works to optimize production in shaded conditions.
@@marcnerius9723 There are some better inverters and panels that can mitigate shade to a large extent. But every situation is different, so I would not take a chance unless adding some optimisers later was really easy and cheap to do.
Living in Northern Norway with 7 month of winter the problem isn't shading by trees but snow covering. Thats why I prefer micro inverters (APsystems with 2 or 4 independent channels). On the other side I don't like the idea of replacing a micro inverter in winter time. So it's not an easy decision.
Thank you so much for sharing! I live in Texas so I didn't even think of the snow idea, but thats a very fair point!
@@solartimeusa I would like to test the difference of bifacial panels and usual panels next winter. Reflected light to the bakside (snow is an excellent reflector) would not only give a little more power but also warm up a snow covered panel faster. There is little experience how much faster the snow is smelting. At least we have no problems with overheated panels or micro inverters 😀
I love watching your videos and your brutal honesty.
I so appreciate this comment.
I'm thinking abt adding solar panel at my home in Manchester, UK which is 70% of the year is cloudy. I got few quotes & most wants me to put in MicroInverter. One installer suggested to use Aiko 455w Gen2 solar panel which got Partial Shading Optimisation in built it along with Sun Synk 5.32kw inverter & 2x5kwh Sun synk battery. With 16 panel he sugested it would generate abt 6200kwh annually. I'm really struggling with understanding various component and which to go for. Thanks for helping me ignore MicroInverters as I agree there are more cons with them then pro.
I wonder if you have any suggestiong/opinion on setup I was proposed with Aiko Solar panel? I would really appreciate your thought on it. Thanks for great videos -really helped me in my journey in understaing this Solar world.
Martyna, what my thoughts are? Love your videos! You did not mention, Half-cut Solar cells! Isn't Half-cut Solar cells in Solar panels the main reason Micro inverters and Optimizers are basically obsolete, for all the reason you mention. I think new, Half-cut Solar Panels have twice the Diodes of older panels allowing shading to internally route around shaded parts of the Panel? Hope I said that right.
I pulled this off Google AI. Yes, half-cut cell technology on solar panels significantly decreases shading problems by allowing the panel to produce power even when parts of it are shaded, as the cells are wired in smaller, independent sections, meaning a shaded area only impacts a smaller portion of the panel's overall output compared to a standard panel where shading on one cell can affect the entire row of cells.
I have Panels on my Boat, Cabin and soon new house we are building. I have a waterproof design to cover a 14' X 40' Patio with only Bifacial Panels. The Panels will be installed without anyone on the roof!!
Anyway, I thought if you were to mention the benefits of Half-cut technologies it could help drive home the point you are so wonderfully and accurately making.
I got around the string inverter 'single panel failure' issue by putting 4 separate strings (8 panels per string) in parallel to feed the inverter. Each 2.5KwH string is fed into (with proper fusing) the inverter so that if I lose a panel on any particular string, the other strings continue to feed the inverter at their full power level. This seems to (and has been) working great over the last 8 years. I wish I could monitor individual panels, but to date, it looks like everything is producing as expected.
I built it this way because I have a high roof and I'm getting a little too old to climb it! 😀
+1 to Martyna for exposing the benefits of each.
Microinverters for my 35kW ground mount were far far less expensive than the multiple string inverters and easier for install. There are 2-in-1 or 4-in-1 microinverters which helps combine units, causing an overall reduction in "price per panel". You do get combined possible points of failure at that point, but they are relatively inexpensive to replace if they happen to not be covered under warranty.
Which brand of microinverters did you use? on your system?
Great video thanks. I have one question regarding the one point failure argument. By adding optimizer you do you recreate point of failure on the roof ? What happens when an optimizer (which i think less complicated than a micro-inverter) fail ?
Very good point! iF YOU DONT NEED optimizers I would not use them, but if you do, the difference of that point of failure is that that unit is an addition, its not a requirement. So if in 10 years Tigo is out of business ( hopefully not!), you can simply remove the optimizer and plug the panel into a string and it will keep working, whereas if you have a micro, the panel is useless unless the inverter is operational. I hope that makes sense?
@@solartimeusa yes, thanks for the answer
Great video!!💪🏻
I have been thinking this a lot. I think the best approach is multiple lower capacity(4-6KW) string inverters in parallel. That way you can easily adjust solar panels as repair or upgrade. Also redundancy if one fails (I assume you would have to use the battery without close loop), you can keep going.
I have also been thinking (if net metering is alive) to mix off-grid and a grid tied inverter in the setup, instead of going hybrid.
Another great video! Thanks, Martyna!
You are so welcome! Thank you Will!
Hi Martyna. Thank you for putting your time and effort in real time efforts which help users like us gain a lot of insights. I am looking for a solar system for my home and I am considering enphase iq8p and sungrow string inverters as options. Cost is not an issue. The location chosen is one which does not have shadows for a radius of 10 meters. Would enphase be really producing more power than string inverter in such scenarios?
My thoughts?? HHMMMMM What would the difference be if the panels are over 100 feet from the house.. Wouldn't it be a better idea to increase the voltage to run the distance and reduce it at the house? Is that possible with micro's??
Thanks Martyna!
Thank you!
I agree that optimizers from a value standpoint are likely not worth it, plus add complexity, losses, and failure points... but per code, most roof mounted systems (which are the majority) require some type of RSD and I believe the optimizers with RSD built in is likely the cheapest way to meet code.
Great video! One thing you missed and maybe it's not an issue in TX, is rodents. At least 50% of people I know that have solar have had the wires chewed coming off the panels at least once in the last 10 years. One person resulted in a house fire and another with just the whole system off-line till they could get the replacement and company out there to fix it, both simple string inverters. All the rest have either optimizers or micro inverters with little issue but the one panel going down with only the low voltage from that panel not likely catching nesting material on fire. I happened twice to us, before we installed rodent guards around the perimeter of the arrays. My neighbors have brick facing and there's no way to stop squirrels from climbing right up. One of them has a PPA and the company keeps coming out to fix the issue and still haven't installed guards.
Is it possible that more string inverters are more popular because more people try building their own storage devices therefore wouldn't work with micro inverters or am i wrong
With string inverters is there a way to take advantage of the DC to charge Tesla EVs (approx 400VDC)? Currently charging with AC and the car has internally an AC to DC converter to charge the batteries. Thanks
Thank you @Solartimeusa Martyna for your insights! Would you be able to comment on with advantage of having string over micro inverters with battery ? do you suggest which would be better . Hope my q is clear .
When it comes to battery I suggest String HYbrid inverter such as Tesla POwerwall 3 or SOl-Ark. If you plan to add battery in the future, doing string will be an easier upgrade.
Did you mention that the highest DC voltage within the system is string voltage, for string inverters but only panel voltage in the case of micro-inverters? One’s house insurer may have some reservations about a potential 600V (or more) DC source within/without your home? AC is much safer, at mains voltages, than DC - for humans and fire risk.
Edit: mrntioned, sort of, lower down but simply dismissed by some.
Microinverters offer more flexibility and future-proofing for your solar setup because solar panel models tend to get discontinued quickly. Microinverters allow each panel to work independently, so you can mix and match different panel types and specifications. This means you don't have to update all your panels if one model is discontinued, unlike string inverters where all panels need to be the same.
Plus, microinverters make it easy to expand your system. If you want to add more panels later, you won't have to worry about compatibility issues, which can be a significant headache with string inverters.
Also, consider this: the warranty for a panel usually involves replacing it with a similar unit, which almost never has the exact same specifications as the original. The warranty might cover labor costs for removing and installing the defective panel, but with string inverters, this mismatch can make panel warranties practically useless.
String inverters are what you described
Great info! I would also add that the ability to DC couple batteries is so much more efficient. I believe that micro inverters paired with batteries is not the right solution as you are having to convert the electricity 3 times (at the panel to AC, when charging the batteries back to DC, and then back to AC when discharging the batteries). A system like the Tesla PW3 makes all of this a single step process depending on what the home needs. If the battery needs power, the panels feed the PW3 directly with DC power. If the battery is full, the power is simply inverted once and fed directly to the panel. Each time you are having to convert, you’re loosing about 3%.
I'm confused about off-grid vs grid-tie inverters even after getting some traction conversing with support at solartorrents
I just have one question.. Where can I buy an AC battery
Martyna, do you have any opinion on the new PointGuard battery & loadhub system?
Skeptical.... promises too many great things. paid a few RUclipsrs for sponsorships, but the company is young, if the industry will continue to be slow for the next few years, I do not see them sticking around.
I would not put my own money in it. BUT I cannot say negative words about their systems, from what i saw, its pretty impressive, its warranty I am worried about.
ok lady you did a through breakdown of everything 🔥🔥🔥 i install string inverters because is cheaper for customer and not much different if roofs have full sun also because of the need of expensive ac coupled batteries, the difference in price is crazy.
THANKS for being such a cool viewer! Thank you!!!
You got a new subscriber with this video. (I wish your company serve KATY TX - becuase i am looking for a solar system for my house).
Is the warranty of both systems the same? There is video indicating that the micro have lot more warranty than string systems. Is this correct?
I'm looking into installing panels and at least 1 battery this fall. The Mango Power M is my choice of battery, for the moment. The battery would be DC coupled. Because of the east-west orientation of the house and shading issues, I think DC power optimizers will be a must. Definitely don't want to go with micro inverters. The Power M can also be AC coupled, but I would rather have the efficiency of being DC coupled. Would like to get a quote from you, but I'm in NY. Thanks for all your informative videos and taking on microinverters vs optimizers a number of months ago.
After installing 800 systems, When designed and installed correctly, String inverters make more Power, Period. Complexity kills, Computers under panels make little sense in most installs.
THis was a relatively well done video. One thing that is missing from your benefits of Micro inverters is Arc Fault protection. AC Voltage with a 0V crossing helps stop and interrupt arc fault. DC wiring simply does not have that as an option. You somewhat got there with the balancing circuit but not quite.
I personally have a SMA sunny boys in my house and those units are extremely sensitive to arc faults and if there is any detection system, it turns off until an installer checks on it. So it has very sensitive arc fault detection.
is the phrase mute point correct? isn't it moot point?
I need to ask google, i forgot :D
I am planning to go solar my choice is solaredge inverter and LG battery 16.4 kw plus Canadian solar panels! What is your opinion about these choices? Thanks! From California
LG batterys have been recalled in Australia as they are catching fire - google it
Thats a cool setup for sure! What were your other options? I am not a huge solar edge fan, but they have proven to be a very stable company and even though they had some issues in the past, they always come through with their warranty replacements. HOnestly, I probably like them best after SMA for their customer service.
Good luck and I am so happy for you to go solar !
@@solartimeusa Martyna,
What’s your thoughts on LG batteries?
Appreciate your feedback!
Does it make sense in some scenarios to mix them? Like a often shaded roof side and a none shaded one?
Never got a clear explanation of the differences between string and micro inverters
Hi Martyna , unfortunately I had that issue when 3 panels became shaded it would bring down the whole string and the second string . Panels have bypass diodes in them but would not activate . DC optimisers fixed the problem on the 3 panels . Soni would never rule them out.
What kind of inverter did you use? :) Thanks for sharing in advance! Also what panels? Did the solution was placing optimizers on the shaded panels?
I have a hypontech 4kw grid string inverter,
Solar panel are green sun 250w mono panels 2022… .I had to turn that string off and turn it back on again straight away and that would fix the problem until I got DC optimisers and I didn't have to manually every day. I think if you shade three panels very slowly it doesn't activate the diodes but you would have to test this yourself on your setup. If you need any graphs from inverter I can send them on.
Thanks Alan
What type is used with Franklin Home?
Franklin is a AC coupled battery so it has a built in inverter. So you can use either option. The solar system will have its own inverter ( either micro or string) and the battery will in case of FRanklinhave its own inverter.
Let me know which one you installed or plan to install on your home? :)
Despite the neighbors with their professionally installed pv systems using MI's I did a diy install and chose SMA. A year post installation and I am very happy with that decision. I did purchase the SMA 10 year extended warranty, inverter warrantied for 20 years, for only $350 with the Federal Tax Credit. If the inverter does fail in the next 10 to 15 years I will simply replace it. If the pv systems is down for a few days I dont care. hahaha I bank enough credits where it can be down for months. DIY allowed over paneling with the total cost being 1/3 that of professional installation quotes.
I'm convinced that string is the way to go but just have concerns with failure. When the inverter fails does it slowly ramp down or just burn out with no indication? If so, I would be without power for a long time until I can get a new one delivered and installed.
I do not understand what you are referring to as 'single point of failure'. That would be a potential to any system if the design did not adequately account for such things. Doesnt matter if it has batteries or not. A well designed battery backup system could still account for different failure scenarios. Perhaps you can be more specific with your question and context?
Great Video. Thanks for making it!
Glad you liked it! Thank you so so much!
great information please keep making videos i enjoy them
Of course, thank you so much!!!!
Here is my issue with string vs micro single point of failure. If I use a string inverter and it fails, my system is down. which sucks but is not then end of the world. but as i live in a remote area and the large string inverters have to be shipped via freight, when it does fail, I'm out the cost of the inverter AND 2000 dollars in shipping cost. if one or all of my micros fail, usps of ups or fedex can deliver a whole batch of them for under 200 dollars. Nobody ever includes shipping cost in that calculation.
Have you ever seen a DC arc fault fire - i know what i want on my roof with my family living below - micros also have up to 25 year warranties - this is not a fair comparison
Not once have I had a fire caused by an arc. Most modern strings have very very sensitive arc fault detection.
Microinverters "come with a 25-year warranty" but in the majority of cases the main combiner is only on a 5-year warranty. So keep that cost in mind for the future.
Hope that was somewhat helpful. If you havent yet, check out the video I made on String VS micro last year.
@@solartimeusa there was a solar fire a couple of weeks ago on the swimming centre in Sydnry Australia on the pool centre used in the 2000 olympics - arc faults are real and DC strings are dangerous - enphase has circuit breakers for protection - why risk a fire on your home - they are up on the roof in the weather for a long time is my point
Doesn't Enphase require internet connection with a Enphase wifi box. That wifi box is only warrantied for 5 years. How long has Enphase been in business? Nowhere near 25 years. Whats the largest panels their MI support without clipping? Is it less expensive to over panel, increase pv system, with a string inverter or over panel with MI's where each panel requires an MI. ARC faults are the mc4 connectors, which Enphase uses, compatibility issues or installation issues. Those MI combiner boxes require a lot of connections increasing the chance of an arc fault.
@@ridemfast7625 theres no arc faults on an AC system as max voltage of 1 panel not 14 like a string - its called a short circuit an trips the breaker - strings cant be added to over here if the DC goes over 600v so maybe different rules there but enphase far easier to add to - string invertors only 5 year warrantys
GREAT INFORMATION !!!
This is a pre-Beginner introduction video?For people who can't read the advertisement flyers?
This is definitely a beginner level :) More in-depth was the test I did and linked. But everyone gotta start somewhere, do you think?
Excellent informative video
excellent
Thanks! 🙏
Good info.
Wait six months and get one of the new inverters with software that can switch the DC into smaller blocks creating a better AC sine wave. They are getting over 99% efficiency. While 95% to 99% may not sound like much, over a year, it adds up.
Can you explain?
@@wazup3333 I cannot. This video goes into detail about resonance and soft switching. ruclips.net/video/pdyXEbWoVvE/видео.html. My understanding is that a few companies have proprietary software that can change the switching frequency within a single sine wave and maximize use of resonance in order to reduce losses. I just found this video which a stock pump for one of the companies but it has a good explanation ruclips.net/video/2JxbNi4lnUw/видео.html.
Excellent!
Many thanks! :)!!!!
Ironically, optimizers and rapid shutdown devices have much higher failure rates than microinverters. You will spend much more time doing repairs on the roof with optimizers and rapid shutdown devices. Remember SnapRS?
Oh god, i didnt use Generac because it was too early of a product. And they just rushed too fast trying to get into the solar market....
For me, I've always recommended microinverters, because string Inverters are a single point of failure. If something goes wrong with a MicroInverter, it's $180-240 to replace that single inverter, whereas the String inverters, it's $2500~ for a replacement part.
I will say though, your point about DC-DC battery coupling was 100% on the money. The future-proofed system for EV's is probably the system which gives the better DC access (String).
I thought the same.. until you research the details and find home DC EV charging is unlikely for lots of detailed technical reasons.
Can you elaborate? Lots of success with DC / HYbrid systems such as EG4, Sol-Ark or Tesla PW3.
Thank you for sharing your thoughts. I agree that for different situations, different applications will be more beneficial :) Thank you for leaving a comment as well!
I would be reluctant to have 400-500 volts DC on a roof made of combustible material like asphalt shingles. 400 VDC is a far greater fire hazard than 240 VAC. For a rooftop installation where rapid shutdown is required, DC optimizers give you just as many points of failure as as micros. Where the current tech is, I would only consider string inverters for ground-mount systems.
As for batteries being a single point of failure in a microinverter system, I don't see it. I can turn off my battery breaker with no effect on my system's production. Turning off power to the Envoy has no effect on production either; it just kills monitoring and reporting. Put a clamp meter on the branch circuit(s) to the array(s) and you can see they're still producing.
I think you forgot the aspect safety! one solar panel produce around 40volts, with only 12 panels a whopping 480 volts running from the roof cable towards the inverter, if this inverter is installed somewhere inside your house (not everyone has a garage) it can cause dangerous situations, with micro’s the power is inverted to 230/240 volts under the panel and stays the same with 1 panel or 50 panels toward the electrical cabinet.
I was wondering why I had not heard of micro inverters before, until I realized you are only talking about home fixed installations. Oops. I'm in the wrong place. All my research has been for mobile solar installations only. My brother in law installed a home solar system. He got taken for a ride, so much so that I had to lend him thousands of dollars. I will not make that mistake.
I have a string inverter (EG4 18k) waiting to be installed. Along with a EG4 Power Pro and 8 kw in panels.
Ill be upgrading to double the battery size, and more panels (12 kw total?) next year sometime.
Thank you so much for sharing! I do like that mix!
Microinverters are the cat’s pajamas.
Good review. Although in all, it matters less which inverter to use as compared to having any solar PV at all.
People frequently have the incorrect assumption that higher voltage is deadlier, that is only one part of the equation. Here is a simple explanation by Science ABC YT channel Current vs. Voltage: How much Cirrent can kill you? ruclips.net/video/y_cWTWB-N_I/видео.html
I'm an electrical engineer. Are you?
I've used (tried to use) solar for the last 15 years. Things have changed dramatically in that time. In those 15 years solar proved to be a really bad idea (but I was forced to use it). Now it's a better idea.
The cost of panels is 1/4th what I paid. The cost of inverters is 1/10th what I paid. And an inverter for each panel was impossible. Here's what it's about.
A solar cell is a "current" source. You can put them in parallel but you can't put them in series unless they all produce the same current. After "inverting", a solar cell is a "voltage" source. You can put them in series but not in parallel. And with SMPS (switch mode power supplies) you can make myriad electrical sources work in parallel or series optimally... and in sync (like our power grid does).
In a short time, you'll be able to replace inverters on panels like screwing in light bulbs. You have to have a way to clean panels off anyway. And like light bulbs, you'll likely never need to do it because they will last forever.
The light bulb is a good metaphor. We went from arc lights to filament to fluorescent to compact fluorescent to LED string to screw-in LED to... who knows what's next. Right now, the engineering for solar is gen 3 (warmed over gen 1) ... and it's ridiculous.
I hope you're an engineer and just trying to dumb this down for consumption.
Thank you for being an engineer. Your write up doesn't seem to contribute much to the points raised by this video though.
Didn't watch the video.
There's no debate, at least, not with me. When/If I ever get solar installed, I am absolutely NOT, doing the micro-inverters. It's just an extra piece of hardware, that can go bad. No thanks. I'll keep my system, as simple as possible.....and part of that goal, is minimizing the amount of hardware that has the potential to go bad on me.
Thank you for leaving a comment and sharing!
I wouldn't believe you have ever touched an inverter in your life.
Micro inverters suck