It's a long, hard road to recharge your batteries in Shenzhen

It is one of only six charging stations in Shenzhen for the city's electric and hybrid cars, which now number 1,107, but it is surrounded by walls and the gates are closed.

'Have you made an appointment with our boss?' a security guard shouts. 'If not, we can't let you in.'

The charging station, next to the Futian bus station and built for 3 million yuan (HK$3.63 million) by state-owned power utility Southern China Grid, will not see any customers until 4pm, when some of the city's 28 night-shift drivers of electric taxis will start arriving to spend about 90 minutes charging their cars for their shift.

Not all the city's 50 electric taxis can work the night shift because there are too few charging points to recharge them after the day shift.

At another charging station, jointly owned by China National Offshore Oil Corp and Potevio Telecommunications, staff said the users were electric taxis and buses, and they had never charged a privately owned car.

Lu Shiming, who drives an electric taxi, complained that the inadequate charging network confined drivers to a relatively small area of operation and limited most electric taxis to one shift a day, while conventional taxis could do two.

Shenzhen authorities said they would have 13 charging stations operating by the end of the year. But the three that were operating last year - in the Futian and Longgang districts - had only increased to six by July this year.