• Wed
  • Dec 24, 2014
  • Updated: 11:29pm
Monitor
PUBLISHED : Thursday, 16 May, 2013, 12:00am
UPDATED : Tuesday, 21 May, 2013, 9:04am

Don't kid yourself that electric taxis are green

The new vehicles on HK roads are as red as ever if the energy used and gas emissions produced in making them are taken into consideration

Yesterday, the first of a new fleet of electric taxis rolled out onto Hong Kong's crowded streets.

Encouraged by the prospect of generous subsidies from the government's HK$300 million "green transport fund", the Hong Kong Taxi & Public Light Bus Association is leasing 45 battery-powered "e6" vehicles from Shenzhen-based manufacturer BYD.

In time, BYD hopes to replace at least a quarter of Hong Kong's 18,138 liquid-petroleum-gas-fuelled taxis with electric models.

According to the Reuters news service, BYD founder Wang Chuanfu said yesterday that if the city's entire taxi and bus fleets were replaced with electric vehicles, "it will reduce Hong Kong's emissions by 50 per cent".

You have to wonder what he's been smoking.

BYD boasts its e6 cars have zero emissions.

This is nonsense.

For one thing, it takes a lot of energy to manufacture battery-powered cars. BYD's e6 weighs 60 per cent more than a Toyota Crown, the model which makes up the vast majority of Hong Kong's existing taxi fleet. That means it takes a lot more energy to build.

And more energy means greater emissions.

According to a research paper published in last October's edition of the Journal of Industrial Ecology, manufacturing a battery-powered vehicle like the e6 pumps out twice as much greenhouse gas as building a conventional car.

And even when electric cars reach the road, they are not emission-free. Their batteries have to be recharged, which means plugging them into the mains power supply.

 

 

That of course means electric cars are only as green to run as the electricity that charges their batteries.

So if Hong Kong were to generate all its electricity with wind turbines or solar panels, then BYD could legitimately claim its taxis were green.

But Hong Kong's power mix is much dirtier. The government likes to claim the city generates 23 per cent of its electricity from natural gas, 23 per cent from nuclear power and 54 per cent from coal.

But if you scour through the Hong Kong Energy Statistics 2012 Annual Report published two weeks ago by the Census and Statistics Department, you get a different picture.

As the first chart shows, last year Hong Kong generated only 16 per cent of its electricity from relatively clean natural gas. The lion's share - 61 per cent - came from coal.

Working from vehicle emission figures compiled by WWF-Deutschland, we can estimate that a battery-powered car recharged from Hong Kong's electricity supply would be responsible for about 140 grams of carbon-dioxide emissions for every kilometre driven.

As the second chart shows, that is roughly the same as a petrol-driven car would pump out, and about 8 per cent more than a car with a diesel-hybrid engine.

When the additional emissions involved in manufacturing battery-powered vehicles are factored in, the case for electric cars looks even more shaky.

According to the Journal of Industrial Ecology paper, across their whole life-cycle, battery-powered cars recharged with electricity generated from natural gas emit the same amount of greenhouse gases as diesel-powered cars.

If the electricity is generated largely from coal, as in Hong Kong, battery-powered cars are responsible for significantly more emissions than conventionally powered vehicles like Hong Kong's existing LPG-fuelled taxis.

That doesn't mean electric vehicles are entirely pointless. They do shift emissions from the streets to power station smokestacks, which may have health benefits.

Just don't kid yourself that these taxis are green. In environmental terms, they are bright red.

tom.holland@scmp.com

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This article is now closed to comments

amunro
The headline is shooting at the wrong target. We could attack any electric powered transport or machines such as escalators and travelators (even our beloved trams) on the grounds that they are not green. The point is that they *are green* and as te article goes on to say it's actually the generation of electricity where the problem lies. Let's get as much transport as we can over to electricity - at least it cuts roadside pollution - and at the same time work on the power companies - it's not an either/or but a gradual process of change. If we start to criticise one piece of the puzzle for the wrong reasons, it will provide an excuse for inaction on the others, result: *nothing* will change.
impala
In the New Territories, all taxis are green.

Sorry, I couldn't resist.
ianson
Tom's article is blatantly biased. Look how he says "about the same" as petrol-driven instead of saying 3 per cent less (as he said 8 per cent more than hybrids) and his sheepish "may have health benefits" in totally eliminating roadside emissions about which the community has been up in arms, not to mention drastic reduction in noise pollution. And bear carefully in mind that the figures are entirely the creation of this completely unqualified writer attempting a parallel based on material published in a journal (the Journal of Industrial Ecology) which is edited by a well-known environmentalism skeptic Reid J Lifset, an academic who has gone to great lengths to criticise pressure on McDonald's and others to end the use of polystyrene packaging and valiantly defended Procter & Gamble's practices. To reach a properly informed conclusion, try reading this summary of 49 studies (****images.pluginamerica.org/EmissionsSummary.pdf) concluding that massive environmental benefits accrue from EVs. So, starting from his dubious factual basis, as McMurdo points out, Tom does us all a great disservice in skewing his message as he does because the conversion of our transport fleet to electric opens up the fabulous opportunity of gaining massive ecological benefits from pushing down coal consumption at our generating plants. If we don't make that change, we are simply stuck with the filth of petrol and diesel on our roads.
Asynsis
Tom is right to "pop the duck" regarding the predominantly carbon-intensive coal source of the electrical power that we use for the MTR, trams and now some token taxis but so are some of my fellow commentators below.
As an island of first world development in a still-developing region, we need to show much more regional leadership and start to make changes to that energy-generation mix. Plus street air-quality will improve as an immediate, tangible benefit, sparing our vulnerable kids and seniors choking, toxic carbon monoxide, carcinogenic particulate and ozone fumes.
The key then is to begin the transition now: to use less fossil fuels in power generation, meaning government and private sector actively choosing renewables and even nuclear over coal, oil and gas whenever possible.
Using the ESCO initiative (funding vehicles for Green building and Renewables that mean no upfront capital costs for Green features - paid for by their life-cycle savings), we can start immediately by building marine and offshore island wind farms all over the SAR, the lone turbine effort in front of the Lamma smokestacks is a very good start - but now we really have to follow through. Look at what Copenhagen does, for example - the airport final approach is a marine turbine avenue!
The Hong Kong Spin initiative (featuring the original Asynsis-led team), advocates exactly this approach.
****en.wikipedia.org/wiki/Lamma_Winds ****envf.ust.hk/werhk/ ****www.alivenotdead.com/asynsis
johnyuan
Neither is the MTR. Don’t kid yourself it is a green transport. Coal burning for electricity must be so cheap that sub-zero air con in summer and blinding commercial outdoor signs all year round are justifiable. So don’t waste cheap energy?
jeff.ovens.9
****cleantechnica.com/2012/04/18/electric-vehicles-greenhouse-gas-emissions-save-money/
here are the facts:
megafun
Electric Taxi, including the e6, are “Greener”, and your article is most misleading! Addressing your point that the energy required / GHG emitted to manufacture an electric vehicle is say “twice” that of an average car, one must consider the total GHG emissions for that vehicle’s entire life! The same principle is now well established in the analysis of green buildings, where it is accepted that low-to-zero energy buildings takes more than twice the amount of GHG to construct, but since the embedded carbon, or GHG emission, is relatively small compare to the total GHG expected for say 100 years’ life of that building. One therefore considers a low-to-zero energy building very green indeed. In this respect, you ought to have taken an extended life of an electric car, including the battery upgrades and other consumables’ GHG emissions over say 20 to 30 years. It is ignorant newspaper writers like yourself who should be removed and be replaced by suitably knowledged academics – such as the Dean of School of energy and environment at universities, or myself!
megafun
Further to my above comment, I wish to state that the e6, using HK’s non-eco-friendly electricity still beats all petrol cars (except maybe some that does 80 mpg) on GHG emitted per Km. So, if one consider a life of 30 years for a e6, and 5 years for its batteries, the e6’s is so much greener than similar 5 seater cars, of the same size!
Ir Nigel
CEO, Director of Electric Motorsports
captam
The problem with tom.holland is that he rarely looks beyond his charts and graphs.
It's not just a matter of energy efficiency and the relative cost, both financially and environmentally, of manufacturing and powering battery vehicles. In our congested down-down streets its more important to deal with locally produced vehicle emissions. These districts are danger zones for air pollution on a daily basis. Any method of reducing locally produced vehicle emissions at street level should be encouraged.
The filthy power-stations producing the energy to charge batteries, can at least be given some "big stick" and forced to clean up their act.
The most disappointing aspect of the new taxis is that they only carry four passengers. This is a retrograde step. The more passengers allowed in a vehicle the more efficient it becomes in terms of emissions and energy consumption. Almost all Taxis were previously were licensed for five passengers. Transport Department should ever allowed this reduction in the licensed passenger capacity. Having made this mistake it, they should at least reduce the fare for vehicles with only four seats.
megafun
never mind, since the average occupants is 2.

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