Intersolar 2025: Industry “White Paper” highlights Back Contact as the next mainstream PV technology

Munich, Germany – May 9, 2025 – At Intersolar 2025 in Munich, LONGi, Aiko Solar, TÜV Rheinland, China Electricity Council, and China General Certification Center officially presented an industry white paper identifying Back Contact (BC) technology as the leading candidate to drive the next era of photovoltaic innovation. As the world's first authoritative report on BC technology for the photovoltaic industry, the White Paper systematically elaborates on BC technology's industrialization path, core advantages, and sustainable development potential. With mass production cell efficiencies now surpassing 27% and further expected growth, the paper concludes that BC is emerging as the core pathway toward higher solar performance and sustainability.

Key innovation points of BC Technology

• 11% more energy over the lifecycle with BC Solar Cells, thanks to improved light absorption and no front-side metal wiring
• 33% higher energy generation in shaded conditions compared to TOPCon modules
• 60% lowered equipment investment costs for BC production lines due to improved laser patterning process
• 5 times greater production capacity with BC technology’s single-line manufacturing
• BC platform compatibility allows for integration with TOPCon (TBC) and HJT (HBC), with future potential for seamless perovskite stacking
• Cleaner design boosts both efficiency and aesthetics

Back Contact solar cells eliminate front-side metal wiring, which traditionally blocks sunlight. This allows for a completely unobstructed surface and significantly improves light absorption. The result is not just a visually cleaner design but also greater efficiency and higher energy output - with field data showing up to 11% more energy generation over the module’s lifecycle compared to TOPCon technology, the paper states. In shaded conditions, BC modules have even demonstrated energy gains of up to 33%.

Back contact paves the way for a scalable and tandem-ready solar future

The paper also discusses how the combination of perovskite and back contact solar cells is expected to develop and improve over time. As more than just a cell structure, BC is a platform technology - one that integrates seamlessly with other advanced innovations such as heterojunction (HJT), tunnel oxide passivated contact (TOPCon), and even future perovskite tandem layers, the paper states. That would make BC not only a peak performer today, but also future-proof, offering a stable foundation for the industry’s transition to stacked architectures and new applications.

Mass production has entered maturity with cost competitiveness achieved

Once considered complex and expensive, BC technology has now reached full industrialization, the paper reports, marking a major milestone in solar manufacturing. Thanks to innovations such as laser patterning, equipment costs could be reduced by more than 60% and with the upgrading of laser technology, single-line production capacity has been increased by more than 5 times.  

Through the rapid development of laser patterning and the continuous progress of wet process, the production steps of BC cell are reduced from the initial 20+ steps to 12 steps, the overall cell production cost is reduced by more than 60%, and the feasibility of mass production as a mainstream technology is effectively ensured.

This makes BC not only a premium product in terms of performance but also cost-competitive with current mainstream technologies - setting the stage for rapid global adoption.

Outlook: Back Contact offers high value in high-investment scenarios

The paper resumes that for European markets - where land, labor, and quality standards are high - BC modules offer the optimal return on investment. From utility-scale to commercial and residential rooftops, BC modules gain a competitive edge through their unique blend of durability, sleek aesthetics, and high performance. With their lower degradation rates, superior reliability, and high-power output, BC products are poised to become the preferred choice for residential, C&I and utility-scale installations across Europe, the authors conclude.

This white paper was co-authored by LONGi Green Energy, Aiko Solar, TÜV Rheinland, China Electricity Council Solar Energy Branch, and China General Certification Center and officially unveiled yesterday at Intersolar 2025 in Munich. It has been concluded that as the industry transitions from traditional architectures to high-efficiency platforms, back contact would no longer be a niche innovation but rather a blueprint for the future of solar energy.

The full white paper can be downloaded here.

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