The number of private electric cars in Hong Kong has been growing rapidly. From just 1,714 in April 2015, the figure has grown to 4,830 within a year – driven by improved recharging infrastructure, better choice and exemption from the first registration tax. Between January and May, over 1,100 Teslas were sold, accounting for more than 95 per cent of the electric vehicle market.
But are electric vehicles really more environmentally friendly? And is their growth necessarily “green” in the long term? In a recent article in Choice, the magazine of the Consumer Council, we published results of an exercise by overseas consumer organisations, comparing a selection of electric, hybrid, diesel- and petrol-engined vehicles available in Hong Kong.
The carbon dioxide performance of electric vehicles depends crucially on the carbon intensity of electricity generation. Hong Kong is more reliant on coal and less on renewables than other well-off economies. In 2015, our carbon emission intensities were 7 per cent higher than in Germany, where the tests were performed, and 23 per cent higher than the average across International Energy Agency members.
Six different electric vehicles, from super minis to executive cars, were tested. These emitted between 96 and 145 grams of carbon dioxide per km, based on the Hong Kong electricity fuel mix, which is somewhat lower than other cars in the same categories.
The upshot is that using Hong Kong electricity and in terms of well-to-wheel carbon dioxide emissions, electric vehicles offer modest improvements over conventional petrol vehicles of a similar size, and there is little carbon dioxide emission difference between diesel and electric vehicles.
Electric vehicles are much better than petrol or diesel vehicles in terms of local air quality, since power stations burn fossil fuel further from urban populations than car engines. Modern power station emissions are also better controlled than car exhausts, though this gap, in theory, is closing as the Euro V standard becomes fully adopted in Hong Kong.
It is important to consider the impact electric vehicles might have on Hong Kong’s energy ecosystem, especially given our commitment to reduce greenhouse gas emissions. There are half a million private vehicles in Hong Kong.