Enphase vs Fronius | is there a New Winning Shade Solution? | 2021
ฝัง
- เผยแพร่เมื่อ 30 พ.ค. 2021
- Enphase has always been the No. 1 shade solution, but is all that about to change? Mark is well known for being ANTI - Roof Top Power Electronics. Though that has usually stemmed from reliability issues, which Enphase doesn't seem to have a problem with...
So is there a new Shade Solution on the solar block or have we been missing something this whole time..
Watch the Video to find out more.
This video is a must see for anyone looking for a Shade Solution in the near future, especially if you're in Australia!
We'll be returning to the micro-inverter and optimiser mini series shortly.
Featuring - Mark Cavanagh
Editing/Visual FX/Animation - Elliot Moss - วิทยาศาสตร์และเทคโนโลยี
It is good to see some have not fallen for the big microinverter lie. Great video.
G'day Mark,
Well once again mate, thanks for your ongoing research and your no-bullshit, fair dinkum articles and videos.
Funnily enough, I have quite literally just started, in the last few days, sourcing quotes for the insallation of a new Sunpower Maxeon 5 system, with a longer term intention of going the full monty of an Enphase Ensemble system whenever it eventuates here in OZ.
But given your latest insights, well you have stopped me in my tracks mate.
I would certainly be keen to learn of your experiences of the prospective Tigo/Fronius tests as soon as you can please, as this may completely reset my thinking and forward actions.
Cheers
Peter
Thank you, brilliant video.
Very interesting Mark.
Good video, thanks!
Great video, let the truth be told instead of pointless selling.
Great work mate. I think I agree. For me micros and DC optimisers are for roofs with 3 or more orientations. Well done.
Hi all things Electric. You can actually go 3 directions with fronius.www.mcelectrical.com.au/solar-panel-design-north-east-west/
So many variables - your experiments are interesting so thanks for making videos on these topics. I get a lot of shading from street trees from midday onwards but my understanding is that while you could add optimisers or use an Enphase system, the returns aren't really worth it - you will still have shade and the gains might only be a few percentage points. The only Fronius downside (for me) is they only have 2 MPPT inputs so having 4 panel orientations means the strings have to be paralleled. Fronius with 4 MPPTs would be awesome. Cheers.
I use a Fronius 17.5-3M and have 21 (!) strings in different directions connected in parallel. Even different size strings, and different type of panels. If you make sure the MPPT output voltage of each string is within 10-15% of each other, there is no issue at all, and you can connect them in parallel without any problem. I closely monitor the DC current in each string under different weather conditions and found the MPPT's in the Fronius (and all other string inverters i've owned) track all string perfectly.
This is really fascinating. I have been shopping for a long time and thought for shade you just had to go solaredge/enphase, but now it seems maybe not. I had only heard two things: shade = hot spots = killing your panels, and shade on normal panels = 100% loss for the string.
But the shutting off of the diodes is not good for the diodes on the longggg run.. ! If this means a lot for deciding. Idon't know ?
This is incredible
:) thanks
You are a legend
Ha thanks :)
Great video, I would also like to see a comparison between string inverters and DC optimisers like Solar Edge.
Hi Clicker, I wrote a blog about solarEdge here:
www.mcelectrical.com.au/solaredge-inverter-optimiser-review/
Nothing more to say on that topic.
I'm doing Tigo review soon. It's pretty concerning. Stay tuned.
Thank you. This is very useful information. Fight the system! ;-)
Welcome :)
Interesting insights Mark, good work on the testing.
wow, I've been thinking about this a lot the last few days, and wondering how shading myth about a single panel drawing down an entire system could be true, at least without micro-inverters or additional electronic monitoring and bypass devices on a per panel basis. sure there's in expensive ways for panel manufacturers to monitor voltage on either side of them and cut out rather than limit current?
then I heard about this video from Nigel Morris on the Solar Insiders podcast. questions answer and then some!
Nice
Hi Mark, What are your recommendations for a roof mount installation 12 KW system with no shade issues facing 20° south east.
All those guys who think they know it all on Solar Q&A Aus/NZ FB group who goes "Enphase all day every day" can suck on this !!!. Good work Mark..
Thanks Pro whats the best 3 fase inverter in 2022 ??? for about 24 panels
Yes, I am surprised
So was I! I had to test it myself to believe it.
Great video! It seems to me that Enphase microinverters have a lot to improve. In theory those should be able to do every trick that Fronius can do and then a lot more so a well made microinverter should be identical to Fronius at worst.
OH yeah, I wish to stay hooked to the grid , but not use it unless I have to and I don't want to grid-tie the system.
a self-build system, not a package from a company.
Preferably ground mount with heavy gauge runs to the house and shop to avoid v-drop.
Hello Mark, great video!
1. I think a string inverter may outperform microinverter even on shady days due to loss in power in multiple dc-ac conversion. We have a single dc-ac conversion in string inverter.
2. Can you compare the shading problem between enphase and a string inverter with dc optimisers like solaredge?
Great video Marc. Here is a question though. When installing a Gen24, I have 3 areas on the roof one of which is being mostly shaded at 9am and then later clears up at say 11am. Should this are of panels be connected to a separate input on the inverter or does the inverter itself account for those panels being shaded even if they are fed through the same input as the rest of the panels? What are the advantages of running different strings into different inputs?
I use a Fronius 17.5-3M and have 21 (!) strings in different directions connected in parallel. Even different size strings, and different type of panels. If you make sure the MPPT output voltage of each string is within 10-15% of each other, there is no issue at all, and you can connect them in parallel without any problem. I closely monitor the DC current in each string under different weather conditions and found the MPPT's in the Fronius (and all other string inverters i've owned) track all string perfectly.
Thanks Mark, I have stopped promoting optimisers as a shade solution for this very reason. Emphases certainly not worth all that extra money.
What are the limitations? For example expandability compared to micro inverters? And connection to 3 phases etc?
I have been watching your video and thanks god I have found your channel. Question: what panel would you use with the Fornius Gen 24 inverter ?
Hi Towid, thanks :). My pick would be rec, QCells or Canadian. (Most expensive to entry level). But there are several other decent panels. Longi and Trina are also decent entry level panels.
It would be good to see comparison for when the entire bottom half a a panel is shaded, this being the typical situation when the sun is low in the sky.
Interesting! Do you plan to see how SolarEdge optimisers work also?
Hes already done solaredge testing before against Tigo and the solaredge lost.
The main reasons I would get Enphase is becuase
[1] if there is any isue with a pannel, I can see it is with that pannel, with the stings the supplier or installer can always weasel out andy say we dont really know which one is the issue.
[2] Easier to expand
[3] AC power over roof, I can put what Iwant where I want with no issues
I just had a squirrel chew through one of the leads going from a panel to a microinverter. It took out that panel and I only lost 1/36th of my production till I fixed it. Luckily the rodent chewed it by the connector and I had plenty of lead left to just crimp on a new connector and plug it back in. It was super easy to detect since the software told me exactly which panel wasn't working. No hunting around to find which panel had failed. What a PITA it would have been finding the right one if they were all in series.
I am looking into a solar install but my roof space is not ideal but I have no other options, as the panels will point in three different directions (3 panels: East - 3 Panels: South - 6 Panels: West)
I see most inverters are only capable of supporting two strings which means I would have a string with panels facing different directions.
Do I still need optimisers or micro inverters?
Hi Mech, No you dont need micros! Check out this blogwww.mcelectrical.com.au/solar-panel-design-north-east-west/
Very interesting! I am not clear on 1 point that if you shade about 30% of a module but on all 3 sub-string of the module, then module power will reduce about 30% but non of the bypass diodes are activated yet. Technically the current from that module should be drag down 30% then also the power from the string will be down too right ?
All 3 diodes will engage on a string inverter. This is where the microinverter probably has an advantage.
@@markcavanagh good point, so if the MPPT algorithim can scan fast and wide enough we can avoid the problem with local maximum power. I tried to simulate the effect on PVsyst and have the same result. However there is 1 point that this is only true if we have 1 string per MPPT, if there are 2 string in parallel to 1 MPPT then still the string with shaded module will dictate the max power.
If you have more time it would be nice to have some string inverter which not Fronius or SMA to go though same test I don't know if other brands have that good tracking algorithm or not.
@@markcavanagh That is not correct. The bypass diodes activate only enough to keep the maximum current flowing through the rest of the panels in that string. They work exactly the same as optimizers,where some current may be flowing through the bypass diode,and some through the shaded panel. This allows the shaded panel to still output as much power as it can in relation to the amount of shade it has. The more shade it has,the more current will flow through the bypass diode. So you may have say 3 amp's flowing through the bipass diode,and 4 amps flowing through the panel,as the panel is still producing power even in shade.
Does this apply to all the Fronius inverters? i.e. Fronius Primo series or do you need the Fronius Gen 24 string inverter?
The fronius primo "snap inverter" that has been around since 2015 or so has a Global MPPT or dynamic peak manager. Works fine in the shade.
Great channel and videos. Thanks. I am confused on string converters. If you shade part of a panel and lose lets say 100W of that panel doesn't that mean that you lose 100W from every panel in that string? So if I had 10 panels in a string and lose 100W from one I would lose 1000W total? Isn't this how series works? Whatever one panel produces all of the panels are limited to that amount of power?
great question. Over to you Mark at MC Electrical.
isn't that what Mark is saying the bypass diode does, it's there to protect the panel from heat damage due to it becoming a resistor rather than a energy producing cell, but it has the effect of isolating the part(s) of the panel that is/are shaded from the main inverter string. (confusing that there are inverter strings and panel strings, I'm assuming the three strings of a panel are in series and the panel only has one input and one output connection).
@@graw6257 No response from Mark. Which means more than likely my assumption is correct and he's just another salesman selling whatever product makes him the most money not which one is the best. That's too bad. I used to like this channel
@@alastairleith8612 I think that is what he is saying in the video - hopefully he will confirm.
Thanks. I am still confused. Maybe make another video explaining in detail how much power is lost of only a portion of one panel is shaded in a microinverter system vs a string inverter. Thanks again
I am not so interested in shade since I have none but how about Enphase vs Fronius for panels on a roof at many different angles, 2 sides of a colonial dormer, shed dormer etc. Also, can I monitor each panels performance with Fronius?
String inverters can often handle 3 orientations, as long as 2 of the orientations are even number of panels. If it is more complex than that, then yes, choose Enphase (and nothing else). But honestly, needing a micro inverter to monitor panels is so unlikely.. Almost any fault in a panel will also be able to be identified in string monitoring.
So is the point basically that a string inverter uses the more advanced global MPPT while an Enphase micro does not have this more advanced MPPT ?
It all gets to be a bit much info, I just need an honest opinion on a top-of-the-line system to run my home and shop.
Top 48-volt system preferably hooked up to a power wall or electric car battery that I can run as much as possible for a household of 4 and run a welder 220 volts as a hobby, a well pump 220 volts, and a hot water heater 220 volts as well as lights and a 220 volt stove .
I have lotd of rppm fpr panels ground or roof mount and want the best inverter and panel setup.
Hi Robert. Where are you located, I may be able to recommend someone. 48volts would be for an off grid system.
what if you have one or two pv panels completely in the shadow wil it bring the whole system down in a string inverter system.
No, the string system won't be brought down. As long as you have enough panels to keep the string inverter online. So if you have a string of 5 panels, and you shade 2 of them, then yes, some string inverters will not keep working, but some string inverters can run as low as 80 volts, so no problems.
Well
The Enphase has been specifically designed to pair with the SunPower Maxeon panels. It's not going to perform when used in a way it wasn't designed to work.
You’ve got to be joking. Yes Enphase do have a special partner option with a maxeon panel with Enphase optimizer but that’s only 1 panel option config they are marketed by Enphase to work well with thousands of different panels not just maxeon.
@@markcavanagh does it do the bypassing at a cell level? Or simply the cells don’t act as much of a resister as normal bus bars panels when it has some cell shading?
@@stevemcmechan6444 You seem to be confused. Enphase is a microinverter not an optimiser. Enphase should ONLY be used with Maxeon panels. All other panels would use a Solaredge inverter and optimisers. If you're not following those guidelines you have no business selling or installing solar panels.
@@goldenages7089 lookup any Enphase data sheet Eg s270, iq7, iq7a, etc they say what panel cell numbers they support Eg 60cell, 72 cell, etc and what panel voltage range they support. Enphase even at all energy expo when Iv spoken to them always keep touting how they’re compatible with so many thousands of panels on the market (even lg and trina etc). It sounds like your the one who shouldn’t be in the industry, as your contradicting what Enphase themselves and those marketing and own data sheets say.
@@goldenages7089 Another that knows nothing about solar. Tell us all how the enphase microinverter knows when it is hooked to a 370 watt Maxeon panel rather than a 370 watt jinko for example ?.
What happens when your fronius inverter goes down?
And what happens when one micro goes down?
You can see where Im heading.
Would like to hear your thoughts though
Yeh, it’s a common a partly valid argument. Bur let’s put it this way. If one string inverters goes down after a 10 year warranty, replace it with any brand. If one micro fails every year after the 10 year warranty (not unlikely) then you pay for someone to get on your roof every year and replace one micro which must be the same brand and probably must be the same model. You may even wait 20 times longer before you get around to replacing “just” one micro so same energy is lost. Also, if your envoy fails, if the q relay fails, then that’s more expense, and more down time.
Bypass diodes engage much sooner then stated in the video (2:05 and on).
Hi Hans. That's right, they often do. But it depends on the irradiation or the contrast between the shaded section and the unshaded section.
That is correct Hans. The bypass diode does exactly what an optimizer does. It insures that maximum power can still be delivered by the shaded part of the panel while also allowing maximum current to continue flowing through the rest of the panels in that string. The most efficient system is a plain old panel with it's built in bypass diodes,and a good string inverter like the Fronius. I will be doing a series of video's on this soon,and will be measuring current flow through the panel at the diode level.
Because the operating voltage of Enphase inveters, with strong shadow on 1 cell on a panel, string inverter can use 2/3 power, but, Enphase give-up to work becuase the voltage become 2/3 of panel voltage, It is not just a factor of current, it is a factor of the voltage
Yes I agree. It’s mostly a voltage window issue.
Real live tests would make your argument more credible and valid. There so few tests on TH-cam.
Yeh good point. I might try to do that.
I'm the lay person. I thought if one panel on a string is operating at 30% then the rest in that string dropped to 30% and enphase can have one drop to 30% and keep the rest working at full capacity. Is this not how strings work?
@@markcavanagh well they certainly have the sales team at most solar retailers well trained or just missinformed. I was told what I thought was true over and over again and believed it. When you test do you shade every panel or just one? Would be good to see a test on say, 10 panels, where only one is shaded to see which one performs better.
One of the big lies that the microinverter salesman uses,and now most think the same thing.
It's very believable, had me fooled. I still got a fronius anyway as I wanted less failure points.
Joss
What happens if one solar panel fails on a Fronius inverter? Does the whole string fail?
Good question. But that’s a bit of a misnomer from enphase marketing. It depends what you mean by fail. Quality panels very rarely fail in the sense that it will bring down a string. If it did, all of your panels should be checked for water ingress etc. Bypass diodes may fail or a panel may get severely shaded, in this case, that panel or that section of the panel will be bypassed and the system will keep working.
@@mcelectrical Thank you for your reply. I am about to install solar panels and a battery system and was leaning towards enphase.
Is fronius sponsoring these? Another Aussie installer did the same test with the same results. I rather suspect that other string inverters work the same, but it’d be nice if it was tested that way…
Absolutely no sponsorship. I just test because I want to install the best product. Eddie from NRG made the other video. He stumbled on the issue and told me about it. It's pretty easy to test, but not common knowledge.
Is the bypass diode a function of the panel or the inverter? You seem to change the parameters when you describe it with Enphase. Here is another video with some data. th-cam.com/video/UQ9Szhl1ceQ/w-d-xo.html
I can't follow your theory about the loss when shading in the video. You claim that shading one part of the panel reduce e.g 70watts but the other two parts still produce 100watts (bypass diode not activated). Why so? I have understood that the current going through the system is corresponding to the 30W power and thus the whole system is going down respectively until the bypass diode is activated? I believe this was the case also in part 2 video. And as conclusion of this all if one panel part is dropped out by the bypass diode this affects tho the whole system similarly? There is something I don't understand.
I think the illustrations may be confusing you, as they are not technically accurate, but were the simple way to explain production loss. One way to look at it is that the MPPT decides when to activate the bypass diode. It does this by setting the voltage and current at a certain level. A good mppt will not let the string get dragged down by more than the value of a cell string (eg 100w). So if the system was running at 5000w, and one cell string was shaded, the whole string may lose 30 watts or 80 watts, but when the shade drags the system down to more than 100 watts, the mppt on the inverter will find a more efficient voltage and current, and that spot may be at 10 volts lower, which "encourages" the bypass diode to engage.
@@mcelectrical The inverter just chooses the current. If one section gets 10% shadow it can deliver only 90% of the current. If the inverter follows this current then the complete string drops by 10%. Thats one optimum. If the inverter keeps forcing the original current the bypass kicks in and you loose an entire section (one third of a panel). This is a better option if there are more than 10 sections (~4 panels). What you show in the video is not correct. With 10% shadow on only one section the panel can deliver either 270W (Enphase) or 200W (string inverter). Above 33% schadow on one section both Enphase and a string inverter should settle for a bypass or 200W. That gives Enphase a benefit for 0-33% schadow on one section. Not something that happens a lot.
At 4:00 -- you are implying that microinverters somehow prevent bypass diodes from working? Or that Enphase does not have MPPT? And then create hotspots. 100% false.
Inverters do not control bypass diodes in any way.
Maybe it could be said this way: The higher the voltage going through the panel, the higher chance of a hot spot and the higher the reverse module voltage and the higher the chance of a bypass diode engaging. So string inverters will engage a bypass diode sooner, and more regularly in the same shade conditions. More importantly, in most panel and micro combos, if you engage 2 bypass diodes, the micro will be outside of it's voltage range, so it will not do that. I didn't say Enpahse does not have an MPPT or that they create hotspots. Infact i say that this is one of the strenghts of enpahse - it treats the panel gently with low voltage and therefore less stress and less engaging bypass diodes. Anything about this that you disagree with?
Info is out of date.
It's still pretty current. Which part do you think is out of date? I'm assuming you didn't appreciate the info?
Put a shadow over the entire panel and measure the volts. hmm. (which theory is), for the number of volts is not much drops but amperes. would you test the matter physically. We can disagree with the theory. try everything at home. What is the aim here?
exactly.. many bypass diodes won't last long enough, so when the systems gets older, fronius systems has larger probability to produce less and less energy bcs of the bypass diodes failures, and there is hard to see it througj standard monitoring..
While Enphase makse panels last longer and lower degradation, and also a much degraded solar panel wouldnt affect the other panel that is less degraded, while in fronius system you dont know which panel degrades more and drag down the entire system
The diodes in a good quality panel will outlast any microinverter. I have panels that are 22 years old and still output 93% of there rated output. Never had a single diode fail. In most good quality panels you find high quality schottky barrier diodes that just don't fail,as there rated for twice+ the current output of the panel.
@@69Atho how much shade do you have? I think the key question here is if the diodes have to work for several hours every day how long will they survive?
@@markcavanagh can you elaborate more on bypass diodes and durability. How they are build internally? Are they all the same in different panels? How likely they will fail if working every day?
@@markcavanagh if your hypothesis is true why would manufacturers put those disclaimers that you should avoid shade otherwise you loose the warranty. Is it just a copy/paste for past 40 years and nobody reviewed it ever since? BTW why would you replace 10 year old panels? What happen to them? Do they have any resale value? Are they a waste?
biased movie.
Fernando, any part of this that you disagree with? I don't feel the need to be biased. If i thought Enphase was a better shade solution, then we would have kept on installing it.