Buzen City, Fukuoka, Japan

NAS Battery used to balance supply and demand


The World's Largest NAS System helps
balance supply and demand of Kyusyu's
growing solar generation

Photo: Kyusyu Electric Power Co., Inc.
(supplied through Mitsubishi Electric Corporation)

Owner Kyusyu Electric Power Co.,Inc.
System Size 50MW (300MWh)
Commissioning Operation Date March, 2016
Location Fukuoka, Kyusyu, Japan


  • Feed in tariff introduced in 2012 boosted installations of renewable energy (especially solar power) across Japan. In Kyusyu Island, southwest part of Japan, huge amounts of renewable energy (especially solar power) had been installed.
  • Kyusyu Electric Power decided to conduct an experimental project (funded by METI) with 50MW/300MWh of the world's largest NAS system so that they could demonstrate the solution of energy storage systems to handle the extra capacity generated by solar power.


  • Solar power generation is expected to exceed the power demand especially during the daytime of spring and autumn when power demand is low. NAS system optimizes the balance of supply and demand of power by absorbing excess solar power to avoid limiting output from solar.

Additional Benefits

  • This is the first MW-scale project in which a newly developed containerized NAS system was utilized. The containerized NAS system expedited installation drastically, and the huge 300MWh installation was implemented in just six months after NGK received the order.

NAS and the NAS logo are trademarks of NGK INSULATORS, LTD., registered in the U.S. and other countries.