LONGi Claims 35.5% Solar Cell Efficiency

Commercial solar panels are only now approaching 25 percent conversion efficiency, but Chinese solar manufacturer LONGi says it has produced a cell that reaches 35.5 percent.

The result was verified by the European Solar Test Installation, a reference laboratory that calibrates photovoltaic devices. LONGi developed the cell using crystalline silicon-perovskite tandem technology, an emerging approach the company believes could define the future of solar power.

Tandem cells combine different materials to capture more of the solar spectrum. LONGi says the technology could theoretically reach 43 percent efficiency. The company first reported 33.9 percent in November 2023, followed by 34.6 percent in June 2024, before making several further incremental gains to reach its latest result.

LONGi says the achievement is a world record for this specific photovoltaic technology. The claim does not represent the highest solar-cell efficiency overall: the US Department of Energy’s National Renewable Energy Laboratory developed a cell with 39.5 percent efficiency in 2022. Cells reaching 50 percent efficiency also exist, but they are intended for niche applications such as satellite solar panels.

Recommended reading

Plastic Waste Could Become Clean Hydrogen

For the broader market, the critical challenge is not which laboratory or company holds the record. It is whether cells with these efficiencies can be mass-produced and commercialized at a scale that helps address global energy problems.