Longi sets new 35.5% efficiency record for tandem solar cell

Chinese solar manufacturer Longi announced a new world record for a two‑terminal crystalline silicon‑perovskite tandem solar cell, achieving a certified power‑conversion efficiency of 35.5%. The result was verified by the European Solar Test Installation (ESTI) in Italy and follows a progression from 31.8% in 2023 to 34.6% in 2024, with a previous laboratory best of 34.85% certified by the U.S. National Renewable Energy Laboratory.

The record applies to a laboratory‑tested device, not a commercial panel, but it demonstrates that tandem technology can convert more sunlight into electricity than conventional silicon cells. Higher efficiency can increase power output per unit area, potentially lowering electricity costs, reducing reliance on fossil fuels, and improving air quality as solar adoption expands.