OSAKA – Ultra-thin, flexible perovskite solar panels are making their debut at Expo 2025 Osaka, powering utility vests for staff and demonstrating a significant leap in wearable and urban energy integration. Developed through a collaboration between Toyota Group company Toyoda Gosei, solar cell startup Enecoat Technologies, and textile manufacturer Seiren, these innovative solar films weigh less than four grams each, enabling them to power personal neck fans and mobile battery packs.

Unlike conventional silicon panels, which dominate 98% of the current solar market, perovskite cells offer distinct advantages including lighter weight, lower production costs, and the ability to absorb a broader spectrum of light, performing efficiently even under shaded, rainy, or cloudy conditions. Shinichiro Fuki, director of the Toyoda Gosei team, highlighted this as a “world-first initiative” for integrating perovskite solar cells into wearables, envisioning their use in environments where conventional power access is challenging.

In laboratory settings, Enecoat’s solar film has achieved an impressive 21.2% efficiency, converting a substantial portion of solar energy into electricity. Real-world testing at Expo 2025 is now gathering crucial data on their performance under varying climate conditions, with mobile battery packs expected to fully charge within five to ten hours. Tamotsu Horiuchi, director and chief technology officer at Enecoat Technologies, emphasized perovskites’ unique capability to generate power indoors from LED or fluorescent lights, expanding solar application possibilities significantly.

Beyond wearables, perovskite technology is being showcased across the Expo site. Saule Technologies, a Polish firm, has deployed curved perovskite cells in “smart poles” that power street lights, security cameras, and digital signage. Japanese company Sekisui Chemical is demonstrating its one-millimeter-thick solar film on the roof of the event’s bus terminus, while Panasonic Group’s pavilion features perovskite cells integrated into an artistic facade, balancing aesthetic design with energy generation. Yoshiteru Hara, technical director of the Panasonic pavilion, noted the potential for these panels to seamlessly integrate into living spaces, overcoming the design limitations of silicon.

Japan is heavily investing in perovskite research, aiming to generate 20 gigawatts of solar energy by 2040. This strategic focus is partly driven by the nation’s status as the world’s second-largest producer of iodine, a key perovskite ingredient, and its mountainous terrain, which restricts large-scale traditional solar farm development. However, challenges persist, primarily concerning perovskite stability. Dr. Hashini Perera, a research fellow at the University of Surrey, noted that perovskites degrade faster than silicon when exposed to heat, moisture, or UV rays. Researchers are actively pursuing solutions, including stabilizing agents and robust encapsulation methods, with some recent breakthroughs showing tenfold lifespan increases.

Another concern is the presence of lead in perovskites. While studies indicate a low risk of leakage with proper encapsulation, the industry continues to explore alternatives. Despite these challenges, perovskite technology is already enhancing existing solutions; Oxford PV, a spin-off from the University of Oxford, launched the first commercial perovskite-on-silicon tandem panels last year, boosting energy output by up to 20% over standalone silicon cells. Horiuchi believes perovskites will revolutionize urban energy, enabling efficient, on-site electricity generation for buildings and personal devices like smartwatches and smartphones.