So who is winning the electric car race?
Electric cars may be capable of being driven as fast as petrol-powered ones, but sales in Hong Kong and Shenzhen are going at a snail's pace.
Both cities have declared their aim to become the electric vehicle hub of the Pearl River Delta, but so far the emission-free vehicles have caught the attention of a tiny niche market, with Shenzhen better placed to win the race.
'At this stage, Hong Kong won't be able to beat Shenzhen in terms of the quantity of electric vehicles since it does not have car manufacturing,' said Professor Eric Cheng Ka-wai, a specialist in electric vehicles at Polytechnic University.
'The strong government support and favourable policies in Shenzhen also put the city in a more advantageous position.'
About 19 months after Hong Kong supposedly embraced the zero-emission vehicles, the city has 80 such cars including, 37 private ones, out of 650,000 registered vehicles.
Shenzhen, with a strong industrial base and favourable government support, may be in a better position to reach its goal of becoming a hi-tech and low-carbon manufacturing centre. Even so, it has only 339 hybrid buses and 50 electric taxis - carmaker BYD's E6 model - plus 186 privately owned electric or hybrid cars.