Shinichi Sano

The application of Valve-Regulated Lead Acid batteries to wind power generation system

Electric power generation systems using renewable energy sources have an advantage of no greenhouse effect gas emission. Using these systems, we have the essential problem of the fluctuation of electric power output, however. In order to solve this problem, one of the solutions is the combination of the renewable energy system with the battery energy storage system. The VRLA batteries manufactured by Shin-Kobe have been used in order to smooth the fluctuations of the wind power generation. On the basis of these findings, Shin-Kobe has newly developed a VRLA battery, the so-called LL-W type, expected more than 17 year life for the use in the system of wind power generation. Before this LL-W type VRLA battery, Shin-Kobe has already applied VRLA batteries as a LL type to the wind power generation system. On the basis of teardown analyses of the LL type batteries, 7 year life of these batteries has been already proved, as of this time, and the LL type batteries have been still working in the system. The main failure mode of the batteries has been estimated as the corrosion of positive grids. In this practical system of the power generation, on the basis of teardown analyses, the life of the LL type battery was evaluated to be 9 years, although the life of the newly developed LL-W type VRLA battery has been expected to be more than 17 years.

Development of long cycle life valve-regulated lead-acid battery for large-scale battery energy storage system to utilize renewable energy

The electric power generation system using the renewable energy has the essential problem of the output fluctuation. With expanding deployment of renewable energy, it is necessary to smooth the fluctuation of both long and short term frequency. One of the solutions to solve this problem is combining the renewable energy and the storage batteries. It is important to install the large storage system with low cost, long life, and safety. The batteries with large capacity, and high input and output power properties are required. We developed long life VRLA batteries for the load leveling by utilizing nighttime energy storage, LL type VRLA batteries. Then, LL-W type VRLA battery with life expectancy of 17 years for the smoothing the output fluctuation have been developed. These batteries have been applied to control the power fluctuation absorption of the power grid. Furthermore, the VRLA battery which improved input and output power properties, the LL-WS type, was developed.