The merits of electricity grid in Shanghai and sodium sulfur (NaS) storage techniques situation are introduced. High-energy NaS battery energy storage system (BESS) is very suitable for peak shaving of electricity grid. A cost-benefit analysis model of NaS BESS is established to study the electricity price mechanism in load shift in the light of an example of NaS BESS in Meisei University. Capacity price, energy price and twofold electricity price mechanism are discussed under the fixed payback period. The results show that twofold electric power price mechanism is fitter for NaS BESS than onefold energy price mechanism while onefold capacity price mechanism is not suitable for NaS BESS. The discharge price of NaS BESS has an advantage over Shanghai's electricity price in industrial and commercial peak periods when its construction cost descends to 1000 yuan kWh(-1). Copyright (C) 2015 John Wiley & Sons, Ltd.