Okinawa Electric Power Co. has started operating Japan’s first smart grid on Okinawa Prefecture island Miyako-jima, using it to control the supply of renewable energy for the 55,000 population of the remote island. According to The Nikkei, the infrastructure links the existing power grid to a 4 MW solar power plant and a sodium sulfide (NaS) battery complex capable of storing 4 MW of power. Some lithium ion batteries have also been installed. In addition, the system also controls power from existing 4.2 MW wind farms situated on Miyako-jima. Okinawa Electric spent 6.15 billion yen (US$75.8 million) on the infrastructure, two-thirds of which was subsidized by the central government.
The Nikkei continues that up to now, Okinawa Electric has leveled the load to the grid from the wind farms by increasing and decreasing the fuel burned in a thermal power plant. By switching to the use of storage batteries and other smart grid technologies, the company will be able to increase its use of renewable energy resources on the island without increased dependence on the thermal power plant.
The government plans to subsidize the installation of solar power systems in Japan in order to achieve a more than 10-fold increase in generation capacity to 28,000 MW by 2020. Smart grid technologies will be essential to integrating this energy into the national grid. https://www.okiden.co.jp/english/