(LI ZIHENG)

Xu Pengfei (left), China's first individual user of grid-connected photovoltaic (PV) power, introduces PV solar panels to his friend atop his flat in Qingdao, east China's Shandong Province, on January 13, 2013.

As Xu's "personal power plant," the eight pieces of PV solar batteries have a total installed capacity of 2 kw, with a grid-connected voltage of 220 v.

It not only provides electricity for Xu's family, but also sells surplus electricity to the state grid, the first unit to successfully do so in China.