China on Wednesday started construction of the country's first power storage plant recycling retired batteries from new energy vehicles (NEV).

The plant built by the Nanjing Electric Power Company of the State Grid in east China's Jiangsu Province is the largest electrochemistry battery storage power plant of its kind under construction in China.

The plant designed with a storage capacity of 268,600 KWh can provide a daily electricity supply of 500,000 KWh, enough for residential use for 220,000 people per day, said Xiao Jing, Party chief of the Institute of Economic and Technical Research of the Nanjing Electric Power Company.

"The energy storage plant works like a battery charger, storing power during low consumption hours and delivering electricity during peak hours," Xiao said.

The total capacity of retired batteries in this plant is designed to reach 75,000 KWh including 45,000 KWh lithium iron phosphate batteries, 30,000 KWh lead-acid batteries. It will also have a lithium battery storage capacity of 193,600 KWh.

The recycling of retired batteries has become urgent as the batteries from the first generation of electric and hybrid vehicles entered retirement age from 2018, Xiao said. The accumulated amount of retired NEV batteries will reach 170,000 tonnes by 2020 in China.

Xiao explained that although retired batteries can no longer power vehicles, they are still suitable for less-demanding functions such as storing electricity from solar panels and wind turbines, after some repairs and maintenance.

The power storage plant itself is smart energy complex with a rooftop photovoltaic power station and a big data center. It can supply energy by integrating traditional energy power grids and ubiquitous new energy power with smart devices, and provide mobile energy storage with equipment in form of a standardized container each installed with 15,000 KW of power, which can be conveniently transported to cope with emergency for power.