Yakushima (屋久島) is one of the Ōsumi Islands in Kagoshima Prefecture, Japan. The island, 504.88 km2 (194.94 sq mi) in area, has a population of 13,178. Access to the island is by hydrofoil ferry (7 or 8 times a day from Kagoshima, depending on the season), slow car ferry (once or twice a day from Kagoshima), or by air to Yakushima Airport (3 to 5 times daily from Kagoshima, once daily from Fukuoka and once daily from Osaka). Administratively, the whole island is the town of Yakushima. The town also serves neighbouring Kuchinoerabujima. 42% of the island is within the borders of the Yakushima National Park.Yakushima's electricity is more than 50% hydroelectric, and surplus power has been used to produce hydrogen gas in an experiment by Kagoshima University. The island has been a test site for Honda's hydrogen fuel cell vehicle research. (There are no hydrogen cars stationed on the island but electric cars are run by the municipality.)