Wearable solar vests unveiled at Expo 2025

• Toyoda Gosei has been testing the vests in Osaka, Japan, and said the technology is a “world first”
• The technology has so far achieved a 21% efficiency rating
• They come with a mobile battery for storing energy

Toyoda Gosei, part of Japanese car giant Toyota, has developed ultra-thin, flexible solar cell vests that are so small and light they can be worn as utility vests.

Unveiled at Expo 2025, which runs from April to October 2025, in the Japanese city of Osaka, the flexible solar panels are lighter than a single sheet of paper and weigh just 4g. They can be used to keep the wearer cool as they can power neck fans.

Described as a world first by Shinichiro Fuki, general management of development, Toyoda Gosei, the solar cells are not like the silicon solar panels that account 98% of the global solar technology market.

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Instead, they are made of perovskite solar cells, which are lighter, cheaper and can absorb more light, including visible and infrared. Fuki even goes as far to say they can be charged in the shade and in the rain.

Made in collaboration with solar cell technology startup, Enecoat Technologies and textile manufacturer Seiren, the film has so far achieved a 21.1% efficiency rate in lab tests, which allows around a fifth of the solar energy it receives to be turned into energy.

It is now being tested in real-world conditions in Osaka and developers are looking at how they respond to different climate conditions and temperatures, as well as the solar battery it is connected to, which takes five-to-10 years to charge.

In a statement from earlier in the year when the technology was first unveiled, Toyoda Gosei said it can be used for functions such as health management. The cells use high-frequency power source technology to “develop a power control unit that can store electricity”.

The partners developed what they call a “technology for attaching solar cells to clothing without wiring” using Seiren’s “sewing technology”.

Written By

Maximilian Schwerdtfeger Content manager

Max joined The Eco Experts as content manager in February 2024. He has written about sustainability issues across numerous industries, including maritime, supply chain, finance, mining, and retail. He has also written extensively for consumer titles like City AM, The Morning Star, and The Daily Express.

In 2020, he covered in detail the International Maritime Organisation’s (IMO) legislation on sulphur emissions and its effects on the global container shipping market as online editor of Port Technology International.

He also explored the initiatives major container ports and terminals have launched in order to ship vital goods across the world without polluting the environment.

Since then, he has reported heavily on the impact made by environmental, social, and governance (ESG) practices on the supply chain of minerals, with a particular focus on rare earth mining in Africa.

As part of this, in 2022 Max visited mines and ports in Angola to hone in on the challenges being faced by one of the world’s biggest producers of rare earth minerals.

His most recent sustainability-related work came much closer to home, as he investigated the eco-challenges faced by independent retailers in the UK, specifically looking at how they can cut emissions and continue to thrive.

Max lives in South London and is an avid reader of books on modern history and ghost stories. He has also recently learned to play the game Mahjong and takes every opportunity to do so. He is also yet to find a sport he doesn’t enjoy watching.

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