(Invited) Development and Practical Verification of the Redox Flow Battery in SEI

Abstract

More than 40 years have passed since the basic principle of the Redox Flow Battery (RFB) was proposed by NASA. Currently, with the widespread use of renewable energy, demand for energy storage batteries is increasing more and more. MW class RFBs are already in practical use in electric power systems. On the other hand, further improvement of performance and cost reduction are urgent issues for mass introduction of RFBs. A wide variety of research and development activities are being conducted all over the world. The development of RFBs in Japan began with AIST, a national laboratory aimed at the load-leveling of electric power companies in the 1970s. SEI began development as a collaborative research project with a power company in 1985 and has been developing first the Fe/Cr RFB followed by the V/V RFB for commercialization. Along with changes in the situation of the power industry for many years, SEI has delivered about 30 RFBs from large batteries to small ones according to customer's request. In particular, since the establishment of the FIT system in Japan in 2012, a large amount of PV systems has been introduced and the need for energy storage batteries is rapidly rising. With the support of METI (the Ministry of Economy, Trade and Industry), a 15 MW RFB was installed in 2015 and is currently operated by Hokkaido Electric Power Company. In this presentation I will introduce the power situation and the necessity of energy storage in Japan, the history of RFB development in SEI, and the operation experience of some systems. SEI is also developing a new electrolyte technology using titanium and manganese ions, which is one of our latest developments aimed at cost reduction. I would like to introduce these developments as well.