At the recently concluded TaiyangNews & AIKO Solar Workshop on Back Contact Technology in Munich, Germany, on November 13, 2025, the team from AIKO discussed the present and future of back-contact (BC) technology with an audience of installers and EPCs.
In an interview with TaiyangNews Managing Director Michael Schmela, Christian Peter, the Managing Director of Solarlab Aiko Europe GmbH and of AIKO Energy Germany in Düsseldorf, AIKO's sales center for the DACH region (Germany, Austria, Switzerland), delved into the manufacturer’s views on how and why BC technology is gaining ground in Europe and elsewhere.
This is an edited version of Peter’s interview and audience interaction during the event.
TaiyangNews: AIKO runs a Solar Lab in Freiburg, Germany. Many big Chinese module and cell makers operate in Europe, but they don’t have labs. You’ve been in the industry for years and built this one from scratch. Can you share the story behind it?
Christian Peter: I’ve been in the PV industry for about 30 years, starting in the 1990s when it was still a small, almost experimental field. I spent many years with the German equipment maker RENA, which meant I was in China constantly, sometimes more than a dozen times a year. That’s how I first crossed paths with AIKO. It was one of my biggest mechanical-engineering customers, and after years of tough negotiations, Chairman Chen and I developed a strong mutual trust.
Around 2019, he approached me with the idea of doing something together in Europe, the original home of many key PV innovations and once the world’s leading solar manufacturing region. At that point, Europe’s production base had almost completely disappeared, despite having excellent talent. So in 2020, we explored building a full cell-and-module factory here. We spoke to several governments about subsidies, identified Fessenheim in France as a promising site, and even evaluated logistics like glass transport. But the policy environment in Europe simply wasn’t supportive enough. Without competitive conditions, large-scale production isn’t viable, which is why that plan didn’t move forward.
Still, we wanted to create a meaningful technical base in Europe, so I founded the Solarlab AIKO in Freiburg in 2020. There was some skepticism – people assumed a Chinese company came to ‘take technology,’ even though by then China already led globally in PV manufacturing know-how. But Germany still has outstanding engineering and research institutions, and we’ve maintained strong relationships, especially with Fraunhofer ISE, despite its heavy bureaucracy. Some joint projects have worked very well, and we continue collaborating on others.
So, the Solar Lab grew out of long personal experience, trust built over decades, and the conviction that Europe should remain involved in advancing solar technology, even if large-scale manufacturing hasn’t returned yet.
TaiyangNews: Tell us a bit about what happens at the Solarlab AIKO, what exactly you do there, what the advantages are, how the cooperation takes place between you here in Freiburg and China, and where the advantages are compared to other Chinese manufacturers who don't have something like this.
Christian Peter: Our solar lab in Freiburg was originally set up when AIKO was still focused on PERC cells. Back then, we supplied cells to most of the world’s leading module makers. So, many modules installed in Europe already contained AIKO cells without anyone knowing it.
As a cell manufacturer, you need to deliver consistently better quality than your customers’ in-house benchmarks. That’s why we built a dedicated cell lab in Freiburg early on – to diagnose customer feedback quickly, verify performance independently, and work on solutions together. Having Fraunhofer ISE literally across the street has been a major advantage. Their CalLab is one of the world’s reference labs, so we can double-check any measurement immediately and rely on independent validation. That’s something most Chinese manufacturers operating in Europe simply don’t have.
Over time, this setup has grown into a broader engineering and R&D hub. Together with ISE, we work on projects ranging from building-integrated PV (BIPV) to distributed PV applications. The lab also supports our long-term technology development.
On the technology side, we see single-junction silicon cells approaching their theoretical efficiency limit of around 29.6%. Lab results today are already around 27.4%, so there’s not much room left, apart from incremental gains through BC technologies, which we believe represent the peak for single-junction silicon.
For a real leap, you need tandems – stacking 2 cells that absorb different parts of the solar spectrum. Lab efficiencies above 34% are already possible, but these are tiny, fragile samples and far from industrial production. Durability remains a major challenge; even global research projects, including the one run by Prof. Martin Green, who is referred to as the Solar Pope in the PV research industry, testing perovskite and tandem modules outdoors show strong degradation.
So, while tandem cells are promising, we don’t expect commercially viable products before 2027, at least not for mainstream rooftop applications. The global R&D effort is huge, so surprises are always possible, but under normal development timelines, we’re still some distance from mass-production readiness.
TaiyangNews: You’re the clear efficiency leader in BC cells, where further improvements are getting harder. How can AIKO maintain this top position and keep holding the efficiency record?
Christian Peter: Holding the efficiency lead in BC cells comes down to one thing: we keep pushing production technology as far as it can go.
Our lab results, like 27.4% efficiency, are not isolated science projects. Everything we do there is designed to be scalable, so the path from lab to mass production is real. But closing that gap takes a huge amount of fine-tuning across the 27 production steps. Gas flows, temperature control, chemistry stability – there are countless micro-adjustments that together create the final cell, and that complexity makes our process extremely hard to copy.
A big advantage is that we even build some of the key machinery ourselves, especially for our copper contacts. These tools aren’t commercially available, so they’re a natural bottleneck for anyone trying to replicate what we do. And we continue refining aspects like contact layout for shading tolerance, aspect ratios, passivation, and transparency, always in close cooperation with suppliers.
Material purity is improving, reliability requirements are rising, and each incremental step takes a lot of work, but these small improvements add up. On top of that, we use AI and machine learning to analyze the huge amount of production data generated every day. That helps us identify patterns and make ongoing optimizations that further boost yield and efficiency.
This continuous refinement – both in process technology and data-driven optimization – is how we plan to stay ahead.
TaiyangNews: When we look beyond the cell and focus on the module, especially considering all the recent innovations like larger cells, half-cells, rectangular formats, no-gap layouts, and slight overlaps, how much more room is there to push module design?
Christian Peter: We’re pretty close to the practical limits. You have a fixed area to work with, and maximizing active cell area while minimizing dead space is already highly optimized. The ‘blacker’ a module looks, the less inactive space remains. There may still be a tiny bit of improvement left, but the big leap came with the third-generation design – most of that performance gain came from module-level innovation rather than further cell optimization.
TaiyangNews: Efficiency is one part of the equation, but cost is just as important. We’ve seen manufacturers experiment with new encapsulation materials and even switch from aluminum to steel as prices rise. Since you’ve already moved from silver to copper, where do you still see meaningful cost-reduction potential?
Christian Peter: Cost optimization is a crucial topic, especially with today’s market prices; no major Chinese manufacturer is profitable right now. That makes reducing costs even more urgent. The biggest lever is yield: it’s often underestimated, but low uptime or frequent equipment issues quickly drive costs up. Improving yield through better machine optimization, preventive maintenance, and smart algorithms still offers real potential. On the material side, moving fully to copper helps, and there’s a bit more room to fine-tune that. But beyond these areas, there’s not much left; if I had a new big cost lever, I’d already be using it.
TaiyangNews: You’ve stayed very focused – starting with cells, then moving into modules with a distinctive technology and becoming a leader there. Meanwhile, many manufacturers have expanded vertically and horizontally into everything from silicon and batteries to electrolyzers. In the broader context of electrification, where PV is just one piece, where do you see AIKO? Will you stay focused, or diversify as others have?
Christian Peter: Much of the diversification you’re describing is specific to China, where the market hasn’t grown freely. When we evaluated producing in Europe, the business model never added up without subsidies – and even in China today, it only works because the government recognized early on that the energy transition is essential, and backed it with massive support. Thanks to that, the whole world benefits from lower-cost solar, even though many Chinese companies absorb significant losses.
From our perspective, there’s no ‘bad’ solar cell or module, whether it comes from the US, India, China, or anywhere else. It all pushes the transition forward.
As for AIKO, our path has always been shaped by strong European roots: we relied heavily on European production equipment, seriously explored European manufacturing, and built a solid R&D presence here. We’ve kept political dependencies low by operating across several Chinese provinces and focusing on technology rather than local government alliances. That strategy pays off today – our technology-driven approach is widely recognized, including recently in a CCTV documentary in China that highlighted AIKO for that exact reason.
TaiyangNews: Looking ahead to 2030, where do you see AIKO, and how do you expect the PV landscape to look?
Christian Peter: Predicting the future is tricky, but our focus stays firmly on back-contact technology. In Europe, we’re still fine-tuning our sales setup and ironing out some intercultural challenges, but our goal is to combine the strengths of Chinese speed and decisiveness with Europe’s engineering depth and research culture. If we merge those effectively, we can achieve a lot.
We’ll continue with BC, and maybe expand our solutions over time. Batteries will be a major accelerator for PV; self-consumption is booming, and in many cases, PV-plus-storage already pays for itself without subsidies. Add in bidirectional EV charging, and the potential becomes enormous; even using a fraction of an EV battery can offer big value to the grid.
The tech is ready—what we need now is the right regulatory framework. We want to stay flexible, keep participating in these developments, and yes, we’re also working on tandem cells.
TaiyangNews: As a closing message, what would you like to share with your customers and our audience on behalf of AIKO?
Christian Peter: Rather than a long message, I mainly want to thank you for being here. I’ve learned a lot from the conversations during the breaks – that exchange is exactly what we need. We depend on understanding what you and your customers want, and your insights are often more valuable than anything our sales teams tell us.
Even with a physics PhD, there’s plenty I don’t know, and being here with people who have expertise from a completely different perspective is incredibly enriching. That’s what makes this collaboration so meaningful.
So, my message is simple: stay engaged, keep giving us feedback. We’ll take your input back to our teams in China, and because they really listen, we can achieve great things together. And yes, I genuinely believe our product is strong and fun to sell.
TaiyangNews: Thank you, Christian Peter. Now, the floor is open for audience questions.
Audience Question: Are you planning to set up manufacturing outside China? Since current low prices rely heavily on Chinese subsidies – and those won’t last forever – I’m wondering whether you’re looking at places like Saudi Arabia or the Emirates, where labor and energy costs are low. Is something like that in planning?
Christian Peter: Yes, we’re definitely looking into that. I was in Abu Dhabi in the spring talking to potential partners, and I see real potential in places like Egypt, Morocco, and even Turkey with its own incentive schemes. But to do something like this is always cost-intensive, and you really need strong local support.
Unlike companies such as Meyer Burger, we never had lobbyists in Brussels. My meeting at the German Chancellery a few years ago made it clear how complex Europe is – national governments, competing interests, EU competition rules. Even people who want to help often can’t. For us as a company, we need straightforward commitments: If you deliver A, B, C, you get X. We’re open to any region that can provide that kind of clarity, and as a Chinese company, we’re flexible globally.
TaiyangNews: From my perspective, AIKO handled this much more sensibly than many others. I’ve seen a lot of companies jump from country to country – Malaysia, then Vietnam, now Indonesia – just to bypass US trade barriers, only for those routes to close again. That constant relocation drives up costs and often hurts quality, as we’ve recently seen with India’s rapidly ramped-up production.
AIKO, in my view, stayed more disciplined. You focused on your core strengths – cells and modules – instead of chasing every upstream and downstream segment. That stability has clearly worked in your favor.
Audience Question: I want to pick up on what my colleague mentioned. A Handelsblatt report recently said that China has essentially cut subsidies in half. Could that influence prices? If module prices have bottomed out, is it realistic to expect them to rise again at some point?
Christian Peter: Honestly, I really hope prices go up a bit. Right now, even major Chinese manufacturers can barely make money; public financial data makes that pretty clear. So, a price recovery would actually be healthy. Solar will still remain the cheapest energy source; we’re not going back above 20 cents. But a fair range, in my view, would be around 15 cents for a good module, 13 for lower-end, and 17 for premium.
The challenge is that this is heavily political. In China, things can change overnight if the central government decides to intervene. But at the same time, they’re dealing with unemployment issues, so they don’t want to shut factories either. Overcapacity might just be kept alive through cross-subsidies. Predicting this is incredibly hard; I’d love to know the answer myself, but it’s impossible to forecast.
TaiyangNews: What seems likely is that China might cut the roughly 9% export subsidy, which is about 1 cent at today’s module prices. China’s economy is under pressure, and it may not want to keep pouring money into exports, especially since it also wants consolidation in the industry. Everyone is basically waiting to see when this change comes.
Meanwhile, silicon prices have risen sharply this year, and even then, producers still aren’t making real profits. Prices for wafers/ingots and cells have gone up, too, but it hasn’t reached module prices yet. The question is when it will. At the end of the day, Chinese manufacturers need to earn money again; otherwise, quality suffers, and we’re already seeing signs of that because the pressure on costs is so extreme.
Audience Member (continuation): I also came across a Handelsblatt piece saying the Chinese government wants to link all installers and manufacturers to stop the internal cannibalization, because too many companies will otherwise go bankrupt. The author even suggested that China might deliberately push foreign competitors out first and then let prices rise again later – that this could be part of a broader economic strategy to steer global markets.
And honestly, I read a lot, so I know you can’t believe every article, but printed reporting still gives you a certain level of credibility. Just yesterday, I saw something about electricity prices in Germany shifting again. And that ties into the broader issue: you can only push module prices higher if energy prices are high enough to justify the savings. If energy is cheap, the economic case gets weaker.
So, I feel like we’re already in a kind of small paradigm shift, both in terms of how our electrification markets are evolving and what’s happening at the European regulatory level.
Honestly, this doesn’t make things simpler; it actually makes them more complicated. But one thing is clear to me: solar already has the lowest LCOE of any electricity source today. We’re not worried about the basic economics; PV is simply the cheapest power you can produce. No fuel costs, straightforward insurance – there are countless LCOE studies that all say the same thing.
What is being discussed in China, though – and you never know when these things turn into policy – is a minimum efficiency requirement. Anyone producing below that threshold would basically be pushed out of the market. And above that threshold, there could be a set minimum export price. That’s on the table. Whether it happens and where exactly they draw the line, we’ll have to wait and see.
TaiyangNews: Right now, every country that has pushed PV forward is dealing with the same challenge: making electricity markets more flexible. We’re seeing more and more negative power prices during peak solar hours, not just in Germany but also in China and even India. That leads to more curtailment everywhere.
So, the real task now is to flood the market with storage – batteries – on a massive scale, and to digitize the system. Germany is still at the bottom of the EU when it comes to smart meter rollout, which is embarrassing for the bloc’s biggest economy. But that’s the direction we have to go: electrification, flexibility, and smarter markets.
Christian Peter: Exactly, Michael. And just to add one thought: despite all the bad news we keep hearing, I actually see a big opportunity here for German industry. Yes, we’re behind in some areas, but the solutions I see coming from German companies – especially the Mittelstand – are genuinely impressive. At trade fairs, I come across brilliant innovations.
There are solutions out there, and I’m pretty optimistic. This transition in grid management plays to Germany’s strengths in engineering. What we need now is solid system-level thinking. But overall, I see real potential for Germany in this shift.
Audience Question: On the topic of cost savings: I remember reading about a German company that developed a process to cut silicon use in cells by about 30%, and that an Indian investor got involved. Can you say something about that?
TaiyangNews: You’re referring to Nexwafe. Its idea is to reuse a wafer repeatedly to grow new wafers, so the silicon requirement drops dramatically. India’s Reliance invested heavily in it. They’re still at a pilot-line stage in Germany, ramping up slowly. It looks very promising, but we have to wait and see. If it works, it would be revolutionary for PV – but they still have a long road ahead.
Christian Peter: Yes, that’s Nexwafe – a Fraunhofer ISE spin-off from Freiburg, and I know the team quite well. It’s actually based on an older concept. In standard production, you saw wafers out of a silicon block, and like cutting wood, you end up with a lot of very expensive ‘sawdust.’ Nexwafe avoids that by using a seed layer and growing new silicon directly on it, so there’s no sawing waste.
Its pilot production is fairly advanced, but whether it will succeed is another question. The process isn’t as cheap as many assume, and the company is coming to market quite late. The broader industry has moved ahead with huge scale advantages, and scale often beats technically elegant solutions.
TaiyangNews: Exactly, the same thing happened with thin-film. 15 years ago, everyone thought it would take over because the whole manufacturing chain was so much shorter. But the efficiency wasn’t there, and silicon PV became so cheap that thin-film never really broke through. The same issue exists now: polysilicon prices are incredibly low, so NexWafe has a tough environment to compete in.
Christian Peter: Right. Nexwafe has been around for at least 7 years, and the rest of the market has moved fast in that time, so the hill gets steeper for them. I’m rooting for them because I know the people, but realistically, it will be tough.
There are newer silicon production methods, like the fluidized-bed reactor process, which is cheaper and lower-CO₂. One company already uses it. But even then, you still need to mix it with ultra-pure silicon, and the purity requirements keep rising. For high-end modules like ours at AIKO, you need extremely pure material. That makes it hard for alternative technologies to break through.
Audience Question: Can I ask what it actually costs to produce a module?
Christian Peter: Even if I knew the exact number, I wouldn’t be able to share it. But honestly, I don’t know it myself. China keeps those figures extremely secret. You can only estimate based on the losses some manufacturers report. My guess is that real production costs are somewhere in the double-digit cent range.
So when I see TOPCon modules being sold for 8-point-something cents in big utility projects in the Middle East, it’s obvious those prices don’t cover costs. If you just look at the bill of materials – glass, aluminum frames, everything – it’s astonishing that a complete module sells for around €50. If you went to a glazier for a large custom glass frame, it would cost more.
TaiyangNews: Right, and it also depends on what you count as “cost.” There are subsidies involved. A joint Fraunhofer ISE–SolarPower Europe study compared the numbers and concluded that Chinese module production costs are roughly 14–15 cents, and producing the same thing in Europe would cost about twice as much.
With this, we have to end the discussion. Thank you, everyone.
