Competing in the global solar market goes far beyond module and cell efficiency. It requires continuous R&D investment and the foresight to anticipate industry shifts before they happen. Crucially, it means backing your vision even when the rest of the market moves in the opposite direction. This is exactly what solar giant AIKO did by betting on Back-Contact (BC) technology just as TOPCon was becoming the dominant standard. Today, backed by its ABC (All-Back Contact) portfolio and a pipeline of over 1,400 patents, the company has become a global benchmark- ready to challenge competing technologies with record efficiencies, high performance, reliability, and a relentless drive for improvement. We caught up with Dr. Christian Peter, Managing Director of SolarLab and Managing Director of AIKO Energy Germany, at The Smarter-E Europe in Munich.
Dr. Peter, recent data shows that Back-Contact (BC) technology is rapidly gaining market share thanks to the new breakthrough in efficiency. Industry forecasts suggest it could capture between 16% and 38% of the market by 2030. Do you agree with these projections?
Absolutely, we are seeing incredible demand. To be precise, Back-Contact cells were not invented by AIKO, but we have driven their development further. SunPower Maxeon originally developed them as early as the 1980s, and it was always clear that this was the superior technology; however, no one had previously succeeded in bringing it to market at a reasonable price point and in high production volumes. That is exactly the scientific breakthrough AIKO achieved. You can clearly see this by looking at our booth and the growth we are currently experiencing. We are scaling up our industrial capacity while low-capacity drivers are exiting the market, so, yes, I firmly believe in it.
In which market segments do you expect this growth to be the most prominent?
We started with the residential sector because we are asking for a premium price. For residential, it is the easiest because households can invest a little bit more to have the best module on their rooftop. For C&I (Commercial and Industrial) and utility, which is currently a very fast-growing market, we have to calculate the LCOE (Levelized Cost of Electricity). In those segments, at the end of the day, the energy produced by the modules has to be the cheapest.
Initially, we were not quite able to compete there. In the meantime, however, we have become competitive and can even outperform other technologies because we harvest more energy. Therefore, from my perspective, the biggest growth will be in the utility and C&I markets.
Narrowing the focus to the regional level, what are your flagship products for the European market?
We have now introduced our fourth generation at this exhibition. We have this Gen 4 module for all scenarios: residential, C&I, and utility. They look a little bit different. For C&I, we have 66-cell modules; for utility, we have 72-cell modules; and for residential, we still have the 54-cell modules. For the residential market, we also have the Z module, which you can see in our booth. It is totally black and has an extremely nice appearance. So, we have the right product for all these three scenarios.
AIKO is currently retrofitting its legacy PERC production lines into ABC capacity, while also upgrading a portion of its TOPCon capacity in the same direction. This move seems to suggest that you already view TOPCon as a transitional technology. Do you believe the global PV industry is underestimating how quickly back-contact technology is advancing?
I do not think they are underestimating this. We can see a lot of trials from our competitors to also do back-contact. However, as we are the patent owner – and because we have an agreement with TCL SunPower out of the US, we are the patent owners for this – it is quite difficult for other companies. But they all see this; they all recognize that we are leading in terms of efficiency, and I do not think anyone is underestimating it.
AIKO recently announced that its C&I modules have surpassed 25.5% efficiency alongside the launch of the 4th generation. What specific innovations have been introduced with these new updates?
You can see the two modules there, reaching 25.6% and 25.3% efficiency. We are sure these are the best-in-class, extra-assorted modules. What we have done can be separated into two classes. The first is on the cell side: we improved the cell on a semiconductor level, introducing improved passivation layers, improved alloys within the polysilicon, and improved anti-reflective coatings. This cell-level optimization allows you to achieve maybe an extra 5% or 5 watts.
The other side is the module level. On the module level, you always have to decrease the dead area, meaning areas like the frame where no energy is generated. Therefore, we narrowed the space between the strings and also narrowed the creepage, which is the area outside where the sealant is applied on the edges of the glass. For this, we had to invent new sealant materials with a higher breakthrough voltage. We now have 12 kilovolts per millimeter, whereas before it was 9 kilovolts in the market. Consequently, we have a higher active area, which gives us another 5 to 6 watts more. This is the improvement.
From the perspective of cell physics and scale-up manufacturing, how much headroom for optimization is left before the industry is forced to transition to tandem architecture?
That is a very good question. Now we have achieved 27.4% in our laboratory. I think the world record for single-junction silicon solar cells at the moment is 28.1%, and the theoretical efficiency limit is 29.5%, so we are not far away. As you know, this is asymptotically approaching, meaning the efforts to increase it further get higher and higher. I think we are more or less at the end; there will be some small increases, but only incremental steps now.
Let’s talk about bifaciality. AIKO has put a lot of effort into this, pushing bifaciality past 70%. Does this breakthrough now allow you to compete on a level playing field in major utility-scale projects?
In fact, we have even managed to push it beyond 80%. And yes, this is precisely the crucial element for utility-scale projects. While it is more important to have higher efficiency on the front side, if you perform the complete LCOE calculation, the backside efficiency also plays a significant role. Therefore, the higher the bifaciality, the better. By surpassing the 80% threshold, we are absolutely competitive in utility-scale projects.
Regarding certification, your 66-cell module became the first BC technology in the world to receive explosion-proof certification from TÜV Süd. What does this certification mean in terms of unlocking new applications?
This gives trust to the customer. We have a live test in our booth where you can check this: we have two solar modules, one standard module and one of ours, and we cover one cell. You can see that the temperature in the standard module is around 170 degrees, while ours remains below 100 degrees. Furthermore, we are using fire-inherent materials, such as this special insulation material. All together, this brings us to the fire-protection class which we have now achieved and was certified by TÜV Süd. This gives customers peace of mind that their assets are stable.
One of the features of your product is the use of copper metallization instead of silver. Beyond the purely economic benefits, what operational or technical advantages does this solution provide?
Copper offers clear technical advantages over silver paste in solar cell metallization. Better conductivity is a key factor, since pure copper has a resistivity of 1.7 μΩ·cm, compared to approximately 5 μΩ·cm for silver paste, which contains glass frit and binders, not pure silver. This means lower resistance and more efficient current collection.
Furthermore, there is no high-temperature firing because copper is applied via electroplating, avoiding the thermal stress and impurity diffusion associated with silver paste firing. This results in a cleaner, more stable cell with higher initial efficiency and longer operational life.
Another major benefit is the superior micro-crack resistance. Without sintering-induced stress and with stronger copper-to-copper solder joints, with a tensile strength greater than 5N, the cell is more robust against mechanical stress and invisible micro-cracks, a key factor in long-term energy loss.
The result is a higher long-term energy yield, lower maintenance costs, better shading tolerance, reduced fire risk, and stronger ROI, with a more sustainable, cost-stable material.
