Back Contact modules strengthen their lead, with AIKO setting new records at 24.4%

Undisputed Leader: The top 3 efficiency ranks have been held by BC modules for about a year, with AIKO pushing the benchmark to 24.4%, followed by LONGi and Maxeon both exceeding 24%.

Key Takeaways
- AIKO set a new benchmark with a 24.4% efficiency BC module in June 2025, maintaining its long‑held No. 1 rank.
- LONGi’s HPBC modules improved twice in H1 2025, reaching 24.2% efficiency and securing the 2nd rank.
- Maxeon holds the 3rd spot with its 24.1% BC module, after briefly sharing 2nd with LONGi earlier in 2025.

Diving deeper, we now present the progress of the top 3 efficiencies, irrespective of cell technologies. Unsurprisingly, the back‑contact (BC) architecture leads in this area. During H1 2025, the most significant development within the top 3 rankings also occurred in June, with AIKO once again taking the spotlight. The company established a new benchmark by increasing the efficiency of its commercial BC module to 24.4%, surpassing its previous record of 24.2% achieved in May 2024. AIKO has raised the efficiency bar once again, maintaining its No. 1 ranking – a position it has held for all but 2 months within the scope of this report since its debut in March 2023. LONGi and Maxeon shared the top rank for the initial 2 months of 2023. Leveraging its back contact technology, known as HPBC, LONGi now exclusively holds the 2nd rank. The company improved the top efficiency of its commercially available HPBC modules twice in H1 2025. The latest improvement, to an efficiency of 24.2%, occurred in June 2025, up from the 24.1% it achieved in March 2025 when it shared the 2nd rank with Maxeon. Until then, Maxeon had solely occupied the 2nd rank since April 2024. The predecessor to this 24.1% Maxeon module had an efficiency 1.1% lower in absolute terms and was not even among the top 3. Before Maxeon provided proof of commercialization to secure the 2nd place, LONGi held the rank exclusively since May 2023 with its 23.2% efficiency module. For the preceding 2 months, March and April 2023, the 2nd position was again jointly held by Maxeon and LONGi with 22.8% efficiency. These same 2 modules had shared the top spot for the first 2 months within the scope of this report, January and February 2023. As of June 2025, Maxeon is ranked 3rd, a position that was vacant for the 2 preceding months as both Maxeon and LONGi jointly held the 2nd position. However, from May 2024 to February 2025, LONGi held the 3rd rank with its 23.2% efficiency product. From September 2023 to April 2024, LONGi’s product was ranked 2nd, and Huasun’s HJT module 3rd. This period also saw modules based on non‑BC cell architecture featured among the top 3 of the TOP SOLAR MODULES listing. Further back in time, the 3rd rank was held by Maxeon with a 23% efficiency product in August 2023 and a 22.8% product from March to July 2023, while JinkoSolar’s 22.65% module occupied this position for the first 2 months of that year. It is important to note that as of the end of H1 2025, the TOP SOLAR MODULES list features 3 commercial modules with efficiencies of 24% or higher, all based on BC technology – underscoring BC’s dominance in high‑efficiency products. From January 2023 to June 2025, the top commercial module efficiency improved by 1.4% in absolute terms. Even during the most recent 18 months, from January 2024 to June 2025, the top efficiency improved by 0.4%. In the year 2024, there was a 0.2% absolute improvement in top efficiency, marking the beginning of a broader upward trend. At the start of the year, BC held the top 2 ranks, while HJT was 3rd. In May, the top 3 efficiency spots became exclusively dominated by BC technology. Each of the top 3 positions saw a revision during the year. AIKO, which had maintained the top rank since the beginning of the year with a 24% efficiency module, surpassed its own record by commercializing a 24.2% efficiency product in May. LONGi’s HPBC module, which had held the 2nd position with 23.2% efficiency, remained unchanged until it was overtaken by Maxeon. The latter introduced a 24.1% BC module, pushing LONGi to 3rd and displacing Huasun’s HJT product from the top 3. By the end of 2024, 2 commercial modules had crossed the 24% efficiency threshold.

This text is an excerpt from the TaiyangNews TOP SOLAR MODULES H1 – 2025 report, which can be downloaded for free here.

Top 3 Solar Module Efficiencies

The article reports that AIKO currently holds the top spot in solar module efficiency with a 24.4% back‑contact (BC) module, followed by LONGi at 24.2% and Maxeon at 24.1%. It chronicles the performance of these companies over the first half of 2025, noting that BC technology dominates the highest‑efficiency tier and that AIKO’s record was set in June 2025 after surpassing its own May 2024 benchmark.