Interview: LONGi’s Chao Jia on breaking solar limits and back contact’s big leap

Chao Jia in an interview with renewable energy expert Thomas Hillig on LONGi’s next chapter, raising ceilings, and changing the solar game

At Intersolar Europe 2025 in Munich, solar strategist and moderator Thomas Hillig sat down with Chao Jia, President of LONGi Europe for DG, to explore the company’s role in shaping the past, present, and future of solar efficiency. The conversation revealed more than just a roadmap of product launches. It actually uncovered LONGi’s philosophy, its scientific roots, and a bold commitment to pushing boundaries. Here are the four main insights from the exchange.

1. LONGi’s culture is built on science, not business hype

When asked about LONGi’s position in solar’s ongoing efficiency race, Chao Jia began not with product milestones, but with a story: the company’s name honors the physics professor of its founders. “Our bosses are scientists,” he explained. “They believe in numbers.” This mindset, Jia argued, is why LONGi doesn’t simply follow market trends. It would rather help to shape them.

In 2005, monocrystalline silicon made up just 1% of the PV market. LONGi not only championed monocrystalline technology but shared key intellectual property to accelerate its industry-wide adoption. That shift kickstarted what Jia called the “efficiency revolution” in photovoltaics. The ethos hasn’t changed. From inventing PERC to bifacial modules, LONGi’s past reads like a roadmap of the industry’s major technical milestones.

2. Solar is nearing the physical limits of current technologies

“Today, we’re close to the boundary of single PN junctions,” Jia noted. LONGi has already achieved more than 28% efficiency with current-generation cells, just shy of the theoretical ceiling of 29.1%. That’s why LONGi is turning to back contact (BC) technology, what Jia called the “final boost” for conventional cell architectures.

But this isn’t the end of the line. Tandem cells in the lab have already crossed the 35% mark, and Jia sees the potential to go beyond 40% in the future. At that level, entirely new use cases emerge: “If a cell phone had 40% efficiency solar, it could charge itself,” he said. While those applications remain on the horizon, the lab work is already underway.

3. Back contact isn’t a bet. It’s a data-backed decision

Hillig pointed out how prominently BC technology features in LONGi’s product line. Jia was quick to clarify: this isn’t a gamble. “LONGi doesn’t gamble,” he said. “We invested in every direction, PERC, TOPCon, HJT, tandem. But we follow the numbers.”

The ceiling is clear: around 29%. “Only back contact can take us there,” Jia said. With the company’s leadership grounded in science, decisions are based on technical ceilings and long-term potential, not short-term market demand.

4. The next generation is already here: EcoLife and Hi-MO 9

At Intersolar, LONGi unveiled two key products showcasing its BC commitment. The EcoLife Series, aimed at the residential sector, delivers up to 500W from a 54-cell module with up to 25% efficiency – setting a new benchmark for its class. Meanwhile, the Hi-MO 9 pushes the limits for utility-scale projects, delivering 670W with a bifaciality rate exceeding 80%, addressing previous concerns about BC’s bifacial performance.

These aren’t concepts. They’re commercial products built on the company’s R&D groundwork. “This is what we bring to Intersolar,” Jia said. “The record efficiency isn’t just in the lab. It’s in our booth.”

Watch the full interview here: https://www.linkedin.com/posts/longi-solar-europe_intersolar-solarinnovation-longi-activity-7329084410757005312-V1pH/