|My Tesla Model S|
Image from Locky's English Playground
Everyone who visit this blog often knows that I am an environmentalist and animal right advocate from the start. Recently, my dearest friends are questioning my decision to own an EV (Tesla Model S 60kWh).
- "EV is at best an alternative form, not an effective reducer, of pollution, when societies are still relying on traditional sources of energy. Encouraging greater use of environmentally friendly means of mass transportation may be a more effective way."
- "In a country that relies heavily on green sources of energy, EVs make sense. Till then, what EVs do is just shifting, not reducing, pollution."
- "you can have all cars as EVs. But if your EVs are running on evergy generated by say, fossil fuels, you're back to square 1"
- "Your EVs are using the energy generated inefficiently upstream in the first place. You can't compare bread with flour."
Scientifically, none of the arguments above are wrong. In response to 1), "EV is at best an alternative form, not an effective reducer, of pollution, when societies are still relying on traditional sources of energy. Encouraging greater use of environmentally friendly means of mass transportation may be a more effective way", Everyone knows that EV does not offer sustainable energy production such as solar, wind and water, what it does is to offer a mean to sustainable energy consumption to tap into these renewable energies, which traditional ICE vehicles can never do. This is one of the top reasons why we should switch to EVs in the long run along with the increase in the use of renewable energies.
People in Hong Kong are no strangers to EVs, broadly speaking, the mass transit railway (MTR) is a kind of EV too, encouraging more people to take MTR is definitely a more effective way because the math can be calculated power use (W) per passenger per distance unit (km), so fitting more people into the same number of trains will lower the W/passenger-km. This friend stationed in Singapore shared SMRT's document,
"We can achieve a more sustainable transport system if more Singaporeans travel by public transport. Public transport is, by far, the more efficient mode of transport, both in terms of land and energy use. A single-deck bus transports up to 80 passengers while an average passenger car only carries up to 5 persons. A car carrying only the driver uses 9 times the energy used by a bus and 12 times that used by a train, on a per passenger-kilometre travelled basis. " (p.58)
Using this for our calculation, if an Internal combustion engine (ICE) car carrying on the driver uses 12 times the energy used by a train on a per passenger-km travelled basis with a 35% energy efficiency at best, while an EV can be greater than 90% energy efficient, then that means an EV is at least 2.57 times more energy efficient than an ICE car, which supports the ICE-to-EV comparison that EV is superior to ICE vehicles in terms of energy efficiency.
This brings us to a train-to-EV energy efficiency ration of 12 : 2.57 = 4.67 : 1. So yes, for the case of SMRT, it is more energy efficient than EV.
But I don't agree this to be the case for Hong Kong's MTR trains until I get hold of more statistics. My friend thinks that I am just arguing for the sake of arguing, as a researcher myself, what I do not want is to come to an early assumed answer as my reply because I do realise running a train system requires more energy than that in moving trains.
|Image from the Standard|
Way back in 2007, Green Sense (環保觸覺) has already made it official that MTR is a ridiculously energy wasting company. The Standard reported,
"51 of the 53 MTR stations across the territory in July. It found about 48,000 fluorescent tubes (光管) were used for more than 6,500 advertising boxes... It also checked 29 Kowloon-Canton Railway stations and found 16,400 fluorescent tubes were used to light up advertising boxes... MTR stations switched on from 6am to 1am every day is wasteful as the energy consumption (消耗) is enormous (龐大的). The same amount of energy could be used to light up 76,000 homes a night, assuming that every family switches on two fluorescent tubes for six hours a day"
So how much energy is wasted? Assuming conservatively that each fluorescent tube is of 50W, energy used for JUST advertising boxes in all stations each day is
50W x (48,000+16,400) tubes x 19 hours = 61,180kWh
Considering Tesla Model S 85kWh battery, the energy used in these advertising boxes can charge a 85kW Model S for 61,180kWh/85kWh = 719.8 = 719 Tesla Model S 85kWh each day, which is equivalent to 719 x 400km = 287,600km of range per day!
FYI, data from the Environmental Protection Department shows that as at end of November 2014, there are 1213 EVs in use in Hong Kong, quite likely 70% of this are Tesla EVs. Which means, the electricity use by MTR on advertising light boxes back in 2007 can be used to power the entire Tesla fleet in Hong Kong from 0% to 100% every single day!!!
And this is just the report in 2007, before giant TVs have been installed in almost every station. Even up till now, the MTR website has nothing but this under Corporate Responsibility:
|Image from MTR|
|Image from MTR 2013 Sustainability Report|
Others will say, "well, who cares? If you consider the total number of passengers on MTR each day (318,000 patronage), 61,180kWh is a minute figure. EVs still loses to trains in terms of per passenger-kilometre travelled."
Personally, I will say that's true, but here's an idea,
- Some people do need their cars, to get to places trains cannot, to carry pregnant women, babies, prams, shopping, etc. that one cannot handle or afford on a train,
- Many people simply want a car
For these people, a car becomes a necessity and it is not a matter of persuasion that can change this need. Thus, there is irrational to consider arguing against the ownership of cars to this group of people, instead, one should encourage this group of car buyers or owners to shift to more environmentally-friendly cars. As to what are "environmentally-friendly cars", we will look into that near the end. The bottom line is, this does not mean they will definitely drive their car daily or non-stop, they just tend to take public transportation less frequently. Then, are these these people wrong in they opt for EVs?
In response to 2), "in a country that relies heavily on green sources of energy, EVs make sense. Till then, what EVs do is just shifting, not reducing, pollution." This statement is correct to an extend that EVs work best together with renewable energies which we have previously mentioned, but it is wrong to say EVs is only shifting and not reducing pollution. A key factor that plays a tremendous part is the education behind the owning of EVs. Owners of EVs are often themselves environmentally caring people and they work hard towards a greener future through educating the public. I, am of course among them, but take a fellow Tesla Model S owner Leilani Munter as an example,
|Image from Leilani Munter's Twitter|
In response to 3) and 4), "you can have all cars as EVs. But if your EVs are running on every generated by say, fossil fuels, you're back to square 1", "Your EVs are using the energy generated inefficiently upstream in the first place. You can't compare bread with flour." Of course this is true, particularly if the electricity is generated from coal. Tessum, Hill and Marshall (2014) recently published their research and generated fierce discussions on the internet. However, most people only read the secondary sources such as The Economist without actually going into the primary source and read the paper itself.
|Image from Tessum, Hill & Marshall (2014, p. 2)|
In my opinion, Tessum, Hill & Marshall (2014)'s paper is a fair, objective one and I do not think it is going against EVs at all. The bottom line is, they "estimate total fuel supply chain air pollutant emissions for scenarios where 10% of US projected vehicle miles traveled in year 2020 are driven in 1 of 11 types of passenger cars" and this is a projection into the future of scenarios with ALL 10% vehicles miles travelled running on a SINGLE possible fuel! What they are trying to prove is that an EV's environmental-friendliness depends on the fuel mix (full report here), that coal is the worst and renewables are the best in terms of PM2.5 and Ozone emission, so the US government should spend more on increasing renewable energy production. How is that a research against EV?
Also, the research only focused on PM2.5 and Ozone, but has not touched on Green House Gases (GHG) such as CO2 emission, which will surely bring Gasoline and Diesel deep red if there such a table. But who will consider this, right?
To determine whether you are using cleaner or dirtier electricity for your EVs, you must get hold of some data from your country.
|Improving in most emissions|
Image from enb.gov.hk
|Total GHG trends down once again after 2007|
Image from enb.gov.hk
|Image from enb.gov.hk|
|Image from eia.gov|
|Image from World Coal Association|
|My email and form response to enb.gov.hk back on 17 Jun 2014|
Image from Locky's English Playground
What have you done for your home country lately?
Share this documentary and this blog post around if you want to play a part in protecting the environment.
patronage -- (n) [U] formal the business given to a shop or restaurant, etc. by its customers
talk the talk, walk the walk -- informal If you say that someone talks the talk but does not walk the walk, you mean that they do not act in a way that agrees with the things they say:
Benefits and Considerations of Electricity as a Vehicle Fuel @ U.S. Department of Energy
Elon Musk: The mind behind Tesla, SpaceX, SolarCity ... +YouTube
Annual Report 2013 @MTR
Energy Efficiency of Tesla Electric Vehicles @Tesla Motors
MTR under fire over energy 'waste'
Promotion of Electric Vehicles in Hong Kong @ Environmental Protection Department
MTR > Energy-efficient LED Lighting @MTR
MTR Annual Report 2013
Tessum, Hill & Marshall (2014) : Life cycle air quality impacts of conventional and alternative light-duty transportation in the United States
The ‘electric cars aren’t green’ myth debunked +Shrink That Footprint
Electric Cars Carbon Emissions Around the Globe +Shrink That Footprint
Cleaner than what? Why an electric car may be much dirtier than a petrol one @ The Economist
1990s: Revival of interest @ Wikipedia
Future Fuel Mix For Electricity Generation Consultation Document
California - State Energy Profile Overview @U.S. Energy Information Administration (EIA)
coal electricity, coal power plants @World Coal Association
Racing Extinction Official Website
Louie Psihoyos @Facebook
Elon Musk @ Twitter
Leilani Munter @ Twitter