The headquarters and plant of Sun Flex Nagatanien Co. Ltd. are located in Joban-shimo-funao-machi, Iwaki City, Fukushima Prefecture. Since its founding in 1975, the company, which specializes in freeze-dried foods, has produced products including retort pouches, instant miso soup, rice toppings, and premixes for Nagatanien, and has also manufactured and sold a variety of private brand products. The plant has advanced energy-saving initiatives aimed at compliance with the Act on the Rational Use of Energy, but these have begun to produce diminishing returns. As such, there is a pressing need to utilize renewable energy such as solar power in order to reduce use of primary energy.
To that end, a pilot project to be implemented at the company’s main plant was proposed by Sato Nenryo Co., Ltd., a fuel trading company headquartered in Koriyama City, Fukushima Prefecture, on behalf of the project’s other participants. These participants included Tateyama Kagaku Industry Co., Ltd., one of our corporate investors, and what was then the Abe Lab at the University of Tokyo. The project, entitled “Program for the Development of a Practical Independent and Distributed Energy System Through Digital Grid Router-Enabled Electrical Power Interchanges” was selected to receive a subsidy from the Fukushima Innovation Coast Framework from fiscal 2016 to 2017.
In the project, an independent sub-grid was built between the multiple buildings on the factory’s grounds. DGRs were then utilized to distribute power from diesel generators, solar power systems, and storage batteries to grid-side loads based on their priority level. Electrical power interchanges between DGRs were also possible even during blackouts. Further, grid-side blackouts would trip a circuit breaker isolating the sub-grid from the main grid and the DGRs would then back up the loads, improving electrical security.