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Yakushima, Japan    

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Yakushima is the fifth biggest island in Japan, with a size of 504.88 km² and 13,178 inhabitants (2010). The island’s main economic activity is the production of SiCO3. The total electricity consumption of 7500 million kWh per year is completely covered by renewables. Yakushima is located in the South of Japan main island and is part of Kagoshima Prefecture. Because of its unique scenery and specific ecosystem, most of Yakushima Island is part of the Kirishima-Yaku National Park and World Heritage Site since 1993. The whole surface area of the island is encompassed by the administrative boundaries of Yakushima town. The municipality has committed to become a carbon free island in 2009, and based its strategy to reach this goal on achieving a 100% renewable energy target. The plan is also based on the development of an electrical vehicles (EV) fleet.

When in Japan electricity grids are always monopolies in the hands of the power company operating in the area, Yakushima is an exception. The power grid of the island is indeed owned by Yakushima municipality. Besides, a unique characteristic of the island is that electricity services are split between three distinct activities; generation, distribution and supply side. The municipality owns the power grid, and three local cooperatives are distributing and supplying the electricity in the island, along with Kyusyu Power Company. Finally, Yakushima Denko Company is producing the electricity consumed on the island since the late 1950’s.

The electricity production of the island is based on its natural assets since the creation of the Yakushima Denko Company. The island is indeed benefitting a from an excellent hydropower generation potential: rainfall are approximately twice as abundant in Yakushima as in the rest of Japan (4,500 mm per year) and the island landscape in punctuated by many waterfalls. Since 1953 and the completion of the first waterfall hydropower plant, Chihiro (1,000Kwh), the electricity is mostly produced thanks to hydropower. Thus especially since the implementation of Awa hydropower plant (capacity of 10,9000Kwh) and the upgrading of the two power plants in 1979 – from 1,000 to 1,300Kwh for Chihiro and from 10,9000 Kwh to 32,000 Kwh for Awa power plant. In addition, auxiliary thermal generators have been implemented on the island. They have two advantages: they are used as backups in case of low rainfall and during maintenance. They are particularly important because of the island closed electricity grid. The will of Yakushima’s community and stakeholders to commit to 100% RE target is intimately linked with its history and to the severe climate conditions it has to face. Renewables appeared as the most relevant, robust and safe solution to inhabitants and energy providers since the island is repeatedly impacted by water disasters such as typhoon or flood.

In addition Yakushima launched, in cooperation with Kagoshima prefecture, the “Carbon Free Island Yakushima” initiative. To do so, they have been investigating the potential of new transport technologies, such as EV, HEV and Fuel Cell Cars since 1990. The share of EV is still only in 1% in the island, but the local governments are now working hands in hands with Nissan Cop. And Mitsubishi Cop. in order to develop new electrical vehicles completely powered by renewables. In order to promote EV, Kagoshima prefecture is offering financial incentives to buyers, as high as half the price of the vehicle.

Energy saving and awareness raising among the civil society undergird this transition to a Carbon society. Firstly thanks to education in school and public seminars, but also to a contest called “CO2 Diet” among inhabitants. The aim of this initiative is to lead the inhabitants to reduce their energy consumption in a playful and engaging way.

Finally, Yakushima is seen as a forerunner by Japanese research teams because of its unique situation. Indeed, this case is highly interesting in the current liberalisation of the Japanese electricity distribution market that will be implemented in 2016 spring. Yakushima distribution system is therefore an example to follow in the transition to the Japanese Diet.

Thursday, November 5th, 2015

General Details


Status Quo

Total energy consumption:
7500 million kWh per year
Percentage of RE in the total energy consumption:
Electricity: 100%

Project Features

Scope of engagement
yes Local/regional
Quality of the objectives
No information
Binding effect of the objectives
No information
Energy savings objective
yes Energy Efficiency Target