7.5MW Solar Plant, Storage Battery Combined to Charge Electric Buses

2014/02/13 20:47
Kenji Kaneko, Nikkei BP CleanTech Institute

The government of Kitakyushu City, Japan, announced a project for storing electricity generated at a mega-solar (large-scale solar) power plant in a large-size storage battery and using it for charging electric buses Feb 10, 2014.

The government calls it "Zero Emission Transportation System." In Hibikinada, Wakamatsu Ward, Kitakyushu City, it will introduce electric buses for two bus routes run by the transportation bureau of the city by March 2014 and start operating them by using grid electricity to charge them at first.

Then, the government will build and start operations of a 7.5MW solar plant by October 2014 and begin to use solar electricity to charge the buses. It plans to install a large-size storage battery by April 2015. By storing electricity generated at the plant in the storage battery for charging the electric buses, it aims to establish a system that stabilizes solar electricity output and enables to stably charge the buses only with solar power without using grid electricity.

The government considers the Zero Emission Transportation System as a precursor of a low carbon society, expecting that it will help the government attract (1) bases for import of electric buses, (2) bases for assembling electric buses and (3) companies in related industries. Because the electric buses that the government will introduce are assembled by companies based in different countries, it considers that not only Japan-based firms but also foreign-based firms can be attracted.

The government of Kitakyushu City will carry out the project in cooperation with private businesses. Hibikinada Development Co Ltd and Toray Engineering Co Ltd will form HKK & TEK, a limited liability company (LLC), for the project and establish the system.

The government will run the bus service and engage in activities to solve technical problems related to the service with help from Mitsubishi Heavy Industries (MHI) Ltd, which will provide electric buses. Also, the Toray group will install and run solar power generation, charging and electricity storage facilities.

The capacity of the electric bus is 72 people. Its maximum speed is 85km/h (approx 52.8mph). It can travel 80km per charge. Its body is made by using Toray Industries Inc's carbon fibers and has a lower weight than conventional steel bodies. Also, a high-performance lithium-ion (Li-ion) rechargeable battery manufactured by MHI was employed to improve drive range.

While main components such as carbon fibers and high-performance Li-ion batteries are manufactured by Toray and MHI, the final assembly of the vehicle is done by a South Korea-based firm. Therefore, if the Zero Emission Transportation System were widely adopted in Japan, unfinished vehicles would probably be imported from South Korea to Japan. Hibikinada is about 200km away from the Port of Busan, from which the vehicles are exported, and, therefore, it would become a base for import.

The electric buses will be introduced with support from the "Green Local Transportation Project" of Japan's Ministry of Land, Infrastructure, Transport and Tourism.