Jimmy Melskens, Senior Product Manager from AIKO Solar said that all back contact (ABC) modules outperform PERC in various common reliability tests such as DH, thermal cycling, PID and LID. As the name suggests, ABC modules from Aiko have all their contacts at the back of the panel, thus doing away with all possibility of optical loss on the front. Since the cell structure replaces the use of expensive silver with copper, it also provides a cost advantage, according to Melskens.
He shared that the single-side soldering for the ABC modules lowers the crack risk on edge between connected solar cells to zero, while triple welding strength vs. traditional technology substantially reduces the risk of detachment and micro-cracks.
Aiming to continue on the path, Aiko plans to launch bifacial ABC modules in Q1/2024 with 188-54 cell and 188-72 cell configurations. Melskens admitted that the bifaciality of its modules will be modest as compared to PERC but argued that it will be worth it in the long run. The bifacial module will be followed by a lightweight module next year.
He was speaking at the TaiyangNews Virtual Conference on Reliable PV Module Design Conference, which took place on 26 October 2023. It had key stakeholders active in the various parts of module manufacturing discuss the topic “reliability” to facilitate designing and building high-performance modules that can last for decades.
Moving on to the next presentation so we have uh Jimmy mkin senior product manager at IO solar who is going to talk about combining High reliability with Superior Aesthetics so you can also guess from the title that uh he’s also going to talk about uh he is going to
Talk about the back contact cell technology and module technology from I so Jimmy the floor is yours okay thank you very much for the nice introduction I’ll share my screen I hope my screen is visible yes and so we start so um um this presentation will be about the
Io product and especially with focus on the reliability so we all know I think that it is a back contact configuration and that there’s nice Aesthetics so I would like to tell you a little bit more about those two aspects and a few more things as well so first uh an
Introduction on who is IO actually for the people who are not familiar with IO I will say a few things about that and the best way to do that for me would be to show you a nice video so that is what I will
Do so I I will first let you enjoy this video and then we continue to the rest okay so what you saw there was a nice overview of our production line you can see that it is very automated it is a comprised of a back contact cell configuration so it’s the cell man
Manufacturing process really and uh to put it in the uh numbers that you can see here there has been a strong Focus always on making cells not modules so much that is a more recent development so the solar cell output already exceeds 100 gaws Revenue ex exceeding five billion there’s three
Global R&D bases and more than 177,000 people already what is also special to mention is that there’s very strong emphasis on R&D work if you want to achieve very high efficiencies it’s of course essential to keep on developing and pushing technology always so that’s why there’s a strong focus on this also
Visible in the number of patents filed so then there’s production capacity uh 61 G gwatt is the current annual cell production capacity that is all manufactured in different facilities in China with an R&D lab in Germany uh the module capacity is 25 G gigs already and in the last year there’s been big
Expansion activities all over Europe so the map of Europe is basically divided into different zones as you can see here and uh different people different people from the local countries have been uh found to establish and expand the market over there for instance myself I’m working between the Dutch office in the nland
And the office in dor in Germany there’s different people in in the different regions at the moment we are with 60 people already in the EU and the plan is to expand this to 110 people by the end of this year so then some technological Milestones uh the
Foundation of IO was almost 15 years ago already first uh focus on per per technology aspects then I move towards larger Wafers 20 110 mm wafers then the inter digitated back contact design or the old back contact cell as as is called internally at IO was established and invented efficiency there very high
With 26.5% and then the step was made also to make it into modules which uh achieve efficiencies of already uh already 24% and then the ambition is the bigger ambition is to achieve carbon neutrality in different regions for instance there’s this region in Austria where this is is already targeted to happen in
20 30 and that can be aided with very high efficient panels so then as I said already there’s of course the whole value chain so if you want to do vertical integration all the way you have to master the a complete process flow from po poly silic all the way down to installations
So the focus of IO really although there’s also Investments uh and stakes in the POC silicon work and the wafering work the main focus is really on SEL manufacturing and modules and recently also this so-called One Step once the stop solution has been added to the portfolio meaning that
There is a complete solution for your house that you can get which is panels an inverter a battery and basically everything that a modern house requires but the emphasis emphasis like I said is on the cells and modules so let’s talk a little bit uh more about
This what is then the io ABC module so ABC I already mentioned it is the old back contact cell what this is really is it so new well if we look at academic development we know that it has been going for some decades already it was for a very long time
In in resarch atmosphere and only recently um yeah people begin to recognize that you can really do it industrially I would say this is really the io achievement that you can commercialize this uh rather complicated cell design and really make uh I make a product that is
Commercially viable so now this uh ABC module is basically on the market as it been recognized by different parties that you see on this slide here then basically how does this work for the people who who not so familiar so of course back contact means that all
The contacts are on the back side so there’s no bus bars on the front meaning there’s no shading losses which is uh of course good of course good thing for your current generation so the short circuit Cur current density is improved by this but it also means that the front side can be
Completely optimized for capturing the light and also the surface preservation of the Silicon on the front side is very strongly optimized and this means that your recombination loss or the electrical recommendation losses are strongly mitigated and at the same time you get this very black panel which is aesthetically pleasing of
Course um then to summarize some key features of the ABC module uh you can also Express this in the uh numbers as you can see here so one not uh worthy aspect especially is the temperature coefficient we see that it is really low it’s only minus 26% per degree C which
Still high warranty so for the performance there’s a warranty of 30 years provided then if you employ these panels instead of more conventional perk Tire panels you can see that your yield or your production of your system is significantly higher you can see that
Can be up to 15% more and this is due not only to the higher power output of these modules compared to let’s say competing products but also because the degradation over time is less so we see in the first year that we are below 1% and the annual
Degradation after that year is only less than 35% so that’s also a small amount uh consequence also of having a high power output of your module is that you basically need less uh uh panels to fill the same area to reach the same system output and it means that you can
Reduce the balance of system cost in this way so okay cabling cost for instance they are also reduced so again this is also an aspect where you can save money and the Aesthetics of course I already mentioned it you see in this picture the nice black panel it is very uh attractive for
Building integration also integration in landscapes in densely populated areas like the Netherlands is becoming very important to uh yeah I not disturb the landscape too much and then these types of panels are also really attractive so we talk about reliability of course temperature coefficient is one aspect and degradation over time these
Are important matters as well as the black front without the grid lines uh then we look at the portfolio of IO you can see an an overview here so the residential scenario is shown on the left hand side there’s different types of panels with a foil back side or a
Glass back side so then we call it the Dual glass module for the residential Market we have a 54 cell module or 54 half cells really uh then for the cni scenarios we have uh somewhat larger panels so the installation of large field is is less laborious you see I can
See here that the choice was made for 72 cell modules um and then for utility scenario we’re also I’m going to look at this more that also concerns installation with these large modules available in the single glass and dual glass and also with a white back sheet for let’s say more
Current generation or a black back sheet for more aesthetic appearance uh then if we look again at the comparison in in a bit more detail you would like of course to optimize your yield per square square meter area so here we see the io ABC panel compared to let’s say a
Typical topon module or a typical perk module and you can see that in basically all the parameters that are important the io module is better so then I we talk about the IR rated module power the efficiency temperature coefficient and degradation over time it all results in a higher
Power density and eventually what matters for a customer is the lifetime production of your system if you compare to the perk we are let’s say 19% higher and for the top G comparison it’s a plus of 9% so these are aspects again linked to reliability of
Course uh then when we compare to other a you can see this table here from theang I think very familiar to this community you can see that IO is there on top with 24% and the difference with the other parties is quite significant if you look at the gap between the
Others the gaps are not so large but then near near the top you can see there quite some improvements so this is the a result of pushing this technology with back Contex excellent Sur surface preservation and strong investments in R&D for years uh then when we look at this
Temperature coefficient in a bit more detail we see here a result com coming back from certification test we see that this 26% per degree C is indeed confirmed this is the best result for back contact cells actually and when we put it to the test in real life you
Can see on the right hand side some installation in DOA Qatar and you can see that the lower temperature coefficient of course in this climate temperatures are very high there’s higher Radiance not so many clouds and then uh a low temperature coefficient is really important and you can see for
Inance in this one day that you see here that is already a 2.4% extra gain in what Peak output uh U only due to the I temperature coefficient when you compare the ABC module to a per module then when we look at some other aspects um of course back contacts have all the
Contacts on the back side and it brings some other benefits as well so for front back contacted cells you have to contact of course every cell next to each other from the front to the back meaning that there’s shouldering process where you get some stressed metal lines if you
Have all your contact on at the backs side this is not there so you have all your metallization basically on the rear side and that is attractive of course for let’s say ease of production but also for robustness so if we talk about reliability again here uh suppose your
Panel is bending a little bit because of mechanical deformation due to strong winds or snowfall it’s important also that the metalization inside the module does not get damaged or break and that is much less likely to happen if you have such shouldering only on the back side so actually it’s three times as
Strong as a traditional technology uh further ated also by the fact that we have a lot of bus bars on the back side 20 in fact and this also reduces the uh resistive losses so the charge carries that are generated that need to reach the metalization uh this is uh mitigated
So for performance that’s very good but also for reliability actually the chance of getting micro cracks in your product in this way is also reduced um then when we look in a bit more detail uh as some results from reliability testing so there’s different tests that are defined for typical IC
Norms for instance so we then we talk about damp testing thermal cycling potential in degradation and light Inu degradation without going uh add to the details of everything you can see here in the bottom graph that the perk module is beaten by by EO product in all cases and the
Consequence is that over time so over the lifetime that’s the graph that we see on on the top left that the per performance reduction is uh um much less pronounced so we see that over the course of 30 years still 89% of the performance is retained which is about uh seven or
Eight% higher than the perk competing product so then also I could received recently the SoCal Red Dot award this has to do with the appearance product so you see that in this particular case with a rather black looking roof ton configuration on this building you can see that the uh uh
Panels really blend in well um then we talk about liability aspects of the ABC module a bit more uh we see that c reliability features of ABC module um so then we talk about material I usage uh this is due to the fact that we use high quality anti
Wafers they have very low def density uh then we also make use of uh strongly perating contacts based on polyc silicon and is also the complete avoidance of front siiz silver metalization uh thanks to the inter digitated back contact cell design then on the back side uh we have some options
So the let’s say the more conventional route is with foil we also have a glass uh re side and this ensures an extra lifetime so the per performance warranty then we are at 30 years this is due to a low temperature coefficient and a limited long-term degradation and also
The Shaded per performance of a product is very good so if you talk about hotspot formation this is of course really bad in all panels in our case the temperature of the product and also uh potential hotp that are being formed is significantly lower so then we see a 50
Degree difference actually of the H spot itself when we compare to more traditional product and then there’s also the anti- cracking robust design so that is linked to the fact that we have all the connections on the back side and shouldering stays on the back basically there’s no front to back shouldering
Connections so then that is all reliability aspects and then if you want to exploit the per performance that we have so the high efficiency and also the reliability aspects of course for a real life uh application you’re very interested in the earnings so here just one typical example this is
A house in the Netherlands that you see here so if we compare the ABC a roof a rooftop installation to a perk installation you see that initially you spend a little bit more money but uh after about three years your investment is already earned back and then for the
Remaining 27 years if you consider a 30-year lifetime you see that you can actually uh a reach a net profit in earnings that is 21% higher for the ecosystem compared to competing per product so the initial price that you pay is a little higher but it it is paid
Back very quickly and then you enjoy some extra revenue for many years to come and with that I would like to show you actually the last slide so that is the Outlook so IO is always pushing on R&D like I already said a few times that is translated to these kind of products
So you see that for the let’s say the smaller 54 C module and the larger 72 cell module there are uh current activities ongoing to push up the power output of these modules so these are the products projected to be released over the course of next year uh then we also
Get a bifacial module and a lightweight module which weighs about half of the other ones uh and that is a attractive for rooftops that can carry less weight for instance it’s also easier to install so it should also reduce the balance of system cost even
More and with that I would like to thank you for your attention and I’m happy to take any questions from your side great uh thanks Jimmy it was a nice uh presentation so it is really interesting that uh even IO is planning to come up with a bifacial module with
Back contact cell architecture so can you uh say something about the B faciality how much it is going to be is it going to be less or better than perk you have any IDE well yeah to be honest the bity is a little bit less than
Compared to a perk module because for a perk module you can yeah also optimize very strongly on the back that is also what you need to do there to still gain efficiency because there’s nothing left almost where you can improve but for the IPC cells it is much more important to
Do front side optimization so there is some B faciality there uh I don’t think I can disclose yet what the numbers are but it is a bit more modest than the perk product having said this you should look at the earnings let say the yield
Over a year you will see that the IBC layout if it’s an IO product or not it will be superior to that so the bity is modest but not the key decisive factor I would say in the earnings if you have a very strongly prated front s side and a
Good a very good anti- reflection coating that already pushes up the efficiency a lot yeah so and uh so the bifacial is it going to be glass class or do you have any projects that are running also with the transparent back sheet so uh I think
The IM to go for glass glass because this is also already in the portfolio at the moment okay thank you very much Jimmy that presentation and please stay online and if there are any questions in the chat window please try to answer these questions thank you yeah you’re welcome