Back Contact Technology Is Set To Become The Leading Choice In The Photovoltaic Industry

LONGi considers efficiency improvement as the first priority in determining its technology roadmap. For the entire PV industry, achieving maximum efficiency, at low cost through mass production and a high market acceptance, is the key driver for future investment.

At this point in the ‘Terawatt Era’, the industry is facing a subversive technological shift. Over the next five to six years, BC (Back Contact) solar cells, known for their high efficiency and aesthetics, are set to quickly become the leading choice in the photovoltaic industry. With a growing market share, they are poised to emerge as the mainstream technology for crystalline silicon solar cells.

We have therefore decided to include a substantial portion of BC solar cell technology in our product portfolio. In the first half of 2023, we started the mass production of our proprietary HPBC (Hybrid Passivated Back Contact) solar cells and have already achieved our target yield and efficiency. By the end of 2023, an HPBC production capacity of 30 GW will be in full operation and the majority of LONGi’s overall production capacity will be dominated by Back Contact solar cell technology in the future.

To date, the key challenges for BC solar cell technology have been the low yield and cost-effectiveness. Not only have we upgraded the technology substantially and thereby improved the mass production yield considerably, but we have also modified the manufacturing processes and significantly reduced the cost, thus enabling the large-scale promotion of BC solar cell technology.

I strongly believe that BC technologies offer greater scope for continuous efficiency enhancements than other technologies. In fact, I envisage unlimited potential. This technology has revolutionized the post-Passivated Emitter and Rear Contact (PERC) era.

We have also reached this point as a result of our unprecedented and consistent investment in R&D. From 2012 to H1 2023, we recorded a cumulative R&D investment exceeding 2.5 billion Euros (CNY 20 billion) - the highest R&D expenditure in the industry. Up to June 30^th, 2023, we saw 2,525 different patents issued and approved.

LONGi has developed its own HPBC (Hybrid Passivated Back Contact) solar cell, which is an alternative BC technology with the front free of shading materials in the form of metal contacts. This leads to improvements in photon collection and therefore higher conversion efficiency. It has been developed over time by LONGi’s scientific team and has now achieved commercial viability.

With LONGi embracing BC (Back Contact) solar cell technologies, we plan to enhance this proprietary HPBC technology further. At the current stage of development, our Back Contact solar cells already boast a benchmark conversion efficiency of over 25% in mass production. With the help of the optimized structural design mentioned, the HPBC solar cell technology significantly enhances light absorption and photovoltaic conversion capabilities, resulting in significantly improved module output power. We released the Hi-MO 6 module in November 2022 based on this technology, with an average module conversion efficiency up to 23.3% in mass production.

In addition, BC products are also setting new standards in terms of aesthetics and can be integrated into various application scenarios, in particular the already thriving distributed photovoltaic market. They offer outstanding adaptability and, with increased market demand for both aesthetics and long-term performance and reliability, especially in demanding climate conditions, their market success is unquestioned.