Suppression of large-scaled PV power station output fluctuation using sodium-sulfur battery

Abstract

The large-scaled photovoltaic generation (PV) system that called "mega-solar" is expected to spread for penetrating PV system. But penetration of mega-solar may impact to stable operation of power system such as the load frequency control. As the one of solution for this problem, energy storage system (ESS) is tentatively installed to absorb shortterm fluctuation of PV output. However, since the ESS is still expensive, it is favorable to reduce its required capacity of ESS for saving installation cost. In Wakkanai PV power station, sodium-sulfur (NAS) battery system is adopted as ESS and is operated to achieve suppression of short-term fluctuation and scheduled operation. In this paper, authors propose a control method of NAS battery system for reducing its MW capacity required for fluctuation suppressing based on characteristic of solar radiation.© 2010 the Institute of Electrical Engineers of Japan.