Until recently, Okinawa’s most famous liquid exports were watery lager and awamori, a fiery rice spirit enjoyed locally but little-known abroad. Now Japan’s southernmost prefecture may soon be contributing to a far more ambitious liquid revolution: sustainable aviation fuel (SAF). The prefecture’s little-known subtropical plants hold surprising potential to help Japan’s aviation sector.

Cleaner-burning fuel is critical to meeting the climate targets of Japan’s aviation sector, one of the world’s largest. While testing new aircraft designs that run on entirely new fuels such as hydrogen will take years, international rules demanding that airlines cut emissions are already in effect on a voluntary basis and due to turn mandatory in 2027.

Japan’s government has responded by setting a target that calls for all domestic flights to use at least 10% sustainable fuel, or SAF, by 2030. This push is backed by domestic refining firms. Next month, Cosmo Oil, in partnership with JGC Holdings and Revo International, will start operating Japan’s first large-scale SAF plant at its Sakai refinery in Osaka, turning used cooking oil into 30,000 kilolitres (kL) of clean-burning fuel a year. This fuel will be made available at Chubu Centrair International Airport.

The problem is, much of the SAF produced today relies on used cooking oil (UCO), a product limited by our ability to consume fried food. And while that appetite may be substantial, it pales in comparison to the volumes of non-petroleum oils required to support aviation. This is where a couple of obscure Okinawa plants come in.

𝑇ℎ𝑖𝑠 𝑝𝑖𝑒𝑐𝑒 𝑖𝑠 𝑝𝑎𝑟𝑡𝑙𝑦 𝑏𝑎𝑠𝑒𝑑 𝑜𝑛 𝑚𝑎𝑡𝑒𝑟𝑖𝑎𝑙𝑠 𝑝𝑢𝑏𝑙𝑖𝑠ℎ𝑒𝑑 𝑖𝑛 𝑆ℎ𝑖𝑛 𝐸𝑛𝑒𝑟𝑔𝑦 𝑆ℎ𝑖𝑚𝑝𝑜 (𝑇ℎ𝑒 𝑁𝑒𝑤 𝐸𝑛𝑒𝑟𝑔𝑦 𝐵𝑢𝑠𝑖𝑛𝑒𝑠𝑠 𝑁𝑒𝑤𝑠 𝑚𝑎𝑔𝑎𝑧𝑖𝑛𝑒)