Electric vehicles are being developed by major automobile manufacturers all around the world. In Norway, the country with the highest density of electric vehicles, a proposal is being tabled to ban all petrol vehicles by 2025. Electric vehicles have become popular in Hong Kong too. Within a short period of six years, the number jumped from under 100 in 2010 to over 5,800 by July 2016. The government has put in much effort to promoting electric vehicles and even adopted them in the civil service car fleet. A the end of last year, the first ever Formula E race in Hong Kong also attracted public attention to this new electric trend. Electric vehicles are favoured for their “zero emissions”. But are they the ultimate remedy for air pollution?
Believe it or not, electric vehicles originated even earlier than petrol cars. Back in the 1830s, electric vehicle and electricity-powered trains already appeared in the United States and Europe. However, as the technology of fossil fuel and internal combustion engines rapidly developed, electric vehicles were gradually displaced after 1920. It was during the 1990s, when oil supply was in decline and public concerns regarding air pollution problem were heightened, along with the advances to battery technology, electric vehicles become trendy once again.
At present, most vehicles on the road are petrol and diesel powered, driven by internal combustion engines. In the process, waste exhaust is generated, which becomes a major culprit of roadside and city air pollution. Electric vehicles run on motors directly powered by batteries, and without the waste exhaust they can alleviate roadside air pollution. In addition, electric vehicles start up quickly, recharging is cheaper than petrol, and there are quite a few recharging facilities that are free. All these are attractions to car owners. Also, without the complicated internal combustion engine and the monopoly of major automobile manufacturers, Hong Kong can join in the research, development and manufacturing of electric vehicles.
There are still a few disadvantages with electric vehicles compared to petrol cars. For example, the high cost of batteries. The battery accounts for over half of the cost of an electric vehicle. The price of an electric car can be double that of a petrol car, even with similar specifications. Recharging facilities are also expensive to build. It takes much longer for electric vehicles to recharge, unlike petrol vehicles that spend a few minutes to refill the fuel tank. Long distance travel is also a problem for electric vehicle, particularly to remote sites without recharging facilities.
“The world’s most suitable place for using electric vehicles”
Hong Kong is a metropolis with a dense population and congested roads. The highrise buildings make it difficult for vehicle exhaust to disperse. With dense roads and numerous traffic stops, the situation becomes worse as frequent stopping of vehicles creates more exhaust then the continuous running of internal combustion engines at high power. Hence the Air Quality Health Index (AQHI) recorded at the general and roadside stations often reaches high or above risk categories. Electric vehicles offer a perfect remedy for this case. The shortcomings of electric vehicle, such as their limited range, may not cause major problems for Hong Kong drivers, as most journeys are short.
The Central Policy Unit of Hong Kong released a Study Report on Promotion of Electric Vehicles in HK in March 2015, to provide a policy direction on electric vehicles. The report stated, “It is fair to say that Hong Kong is ‘the world’s most suitable place for using EVs.’
The government indeed promotes electric vehicles in various ways, such as the exemption of first registration tax for electric vehicles. A Pilot Green Transport Fund was also set up, to support new green and low carbon transport including electric vehicles. Franchised bus companies are also subsidised for trials with hybrid and electric buses. The hope is that all buses in Hong Kong will be running at zero emission in future. Electric vehicles are also employed by government departments. A Steering Committee on the Promotion of Electric Vehicles has also been set up, with members including the Secretary for the Environment, the Secretary for Transport and Housing, and the Secretary for Development.
Hong Kong has produced its own electric vehicle brand. Mycar, a small model co-invented by the Polytechnic University of Hong Kong and a Dongguan company in 2009, has been exported to the United States and European countries. The Hong Kong Productivity Council has also worked with a transport company to produce a single-deck electric bus that suits local roads. The prototype was tested in 2015.
There are, however, a few bottlenecks to overcome. The many slopes in Hong Kong mean that more powerful electric vehicles are needed, which also means higher prices and fewer choices. For recharging, most people do not live in houses and cannot park the electric cars in their own garages or beside houses. Recharging takes quite a long time, and makes it inconvenient for car owners to recharge the cars at a distance from where they live. Larger public transport vehicles requires higher power for recharging. Buses can be recharged at bus depots. But there may be problems for minibuses to recharge in the city centre.
Assessing eco performance with regard to raw material extraction
“Zero emission” is the biggest benefit of electric vehicles in improving roadside air quality. However, roadside air pollution is only one of the many environmental issues. We must assess electric vehicles in other aspects, such as battery use and energy efficiency.
Electric vehicles require the use of lithium batteries. The extraction of lithium brings adverse impacts to the environment. When lithium is refined from salt lakes, the water body has to be evaporated, which will damage the lake ecology. And when used batteries are disposed of, the electrodes and electrolyte solution may undergo hydrolysis and oxidation in reactions with other substances, and cause heavy metal ion pollution, fluorine pollution and organic pollution.
Energy efficiency deals with more than the efficiency in using resources. It also refers to the issue of greenhouse gas emissions. A Taiwan scientific magazine has launched a discussion on whether electric vehicles are better than petrol ones in terms of energy efficiency. Electric vehicles run on energy produced from power plant, which has to transported over some distance. Petrol vehicles are directly driven by internal combustion engines. Assuming the power plant also runs on fossil fuel, the energy efficiency of a petrol vehicle is only half of that of a power plant, as the internal combustion engine cannot sustain a high work level. Although there is energy loss over the long distance transport of electricity to an electric vehicle, overall the energy efficiency of electric vehicles is still higher than that of petrol vehicles. In other words, electric vehicles can put energy to better use and reduce greenhouse gas emissions. There is one assumption though: which is that the electricity of electric vehicles does not come from power plants with poor efficiency. Research in the United States has shown that in some regions which employ fossil fuel power plants, the overall carbon dioxide emissions generated by electric vehicles are higher than that of petrol vehicles.
No matter how excellent the performance of electric vehicle may be, it still consumes energy and causes carbon emissions. When we talk about “green transport”, we pay attention to the performance of individual vehicles, but more importantly we must put the focus on the overall transport planning. Electric vehicles do not solve the problems of congestion and efficiency. As it becomes a new eco-trend and the price falls and popularity rises, the result will only be an increase in vehicle numbers and extra burdens on the environment and transport. There are already quite a few free recharging stations for electric vehicles. If the public is misled into thinking that driving is cheap then the consequences will be dire.
Electric vehicles do not generate waste exhaust directly, but the burden is transferred to power plants. It is therefore equally important to take into account the pollution and carbon emission of power plants. Clean energy is essential. Using electric vehicles are one way to solve the problem of roadside air pollution, yet it is not a cure-all for clean air. The ultimate green solution is to encourage the use of mass transportation and redesign the road networks, to reduce excess mileage and congestion due to poor transport planning.
Text ｜ Henry Lui