Analysing the potential of electric vehicles in improving the air quality of Hong Kong

Abstract

The air quality of Hong Kong (HK), especially at the street level, has

been a matter of grave public concern. In 2007, road transport was reportedly the

major source for emission of carbon monoxide (CO) and respirable suspended

particulates (RSP), as well as the second largest source for emission of nitrogen

oxides (NOx) and volatile organic compounds (VOC). The Government has

taken various measures to curb roadside pollution. Recent technological

breakthroughs in electric vehicles (EVs) have regenerated the Government's

interest in promoting the wider use ofEVs. The main objectives ofthis paper are

to examine whether road transport-related measures adopted by the Government

have been effective in coping with the air pollution problem and whether the EV

policy would improve the air quality ofHK.

The Government has taken a more proactive approach, since 1999, in

dealing with roadside pollution problems. The emission of all major air

pollutants from road transport against the continuous growth in the numbers of

vehicles and vehicle kilometers travelled reduced significantly between 1994 and

2007. The reduction of S02, RSP and CO in this time period was 95%, 70% and

59% respectively. Nonetheless, air pollution in HK remams an unresolved

problem as reflected by continuous rising trends in the hours with poor visibility,

days with roadside Air Pollution Index exceeding 100, and concentration of some

air pollutants exceeding the Air Quality Objectives.

EVs have zero tailpipe emission but its potential in improving the air

quality has been skeptical because part of the emission may be transferred to the

power plants. Through quantitative analysis, it was found that if all vehicles in

HK were converted to EVs, the overall emission of NOx, RSP, CO and VOC

would reduce by 77.3%, 89.9%, 99.4% and 99.4% respectively but that of S02

would suffer a regrettable 13.5-fold increase. It was concluded that the wider use

of EVs should be beneficial to the air quality of HK but the potential benefits

would depend on the number of vehicles to be converted and simultaneous

measures to cut S02 emission at the power sources.

A qualitative analysis was made on factors affecting the change of

vehicles to EVs. It was found that consumer decisions on EV purchases are likely

influenced by availability, choice of models, driving range, reliability, whole life

costing, and adequacy of infra structural support. The use of greener fuel and

surplus electricity generation capacity as a means to reduce emissions from power

plants were also explored. The paper concludes by making recommendations to

encourage use of EVs and to maximize its potential benefits. It is expected that

the Goverrunent will play an important role in implementing EV-related policies

and prioritizing measures to reap immediate benefits.