Electric Vehicles – Part I, How Green Are They?

Electric vehicles (EVs), touted as the next generation vehicle to make the Earth a greener place to live in. The effort to push through EVs and phase out gas (also known as petrol) powered cars has been welcomed by many people and governments as a significant step towards fighting global warming. I am choosing to stick with global warming rather than climate change, because as mentioned earlier, climate change was a term coined during George Bush’s presidential campaign in order to soften the impact of the words.

This will be a 3-part series on EVs – the environmental impact, the future and the politics behind it.

But how green are EVs, and do they really make the Earth a better place?

Let us look at some basic statistics first. According to United States Environmental Protection Agency (US EPA), we produce an average of 8,887g of carbon dioxide (CO2) per gallon of gas burned, and an average passenger vehicle emits 404g of CO2 per mile travelled. We convert that to the metric system and get an average result of 2,348g of CO2 per litre of gas burned and 251g of CO2 per kilometre travelled.

Production Of Electric Car Battery
According to Massachusetts Institute of Technology (MIT) Climate Portal, EVs use lithium battery, which are extracted from hard rock mines or underground brine reservoirs, and much of the energy used to extract and process it comes from CO2-emitting fossil fuels. Mining such materials is labour intensive (dubious labour laws in countries of mining), requires chemicals and water (often in water-scarce area), with the end result of other forms of pollution, such as water pollution. The manufacture of the batteries require heat between 800 to 1,000 degrees Celsius, a temperature that can only be reached cost-effectively by burning fossil fuels, which again adds to CO2 emissions.

In summary, manufacturing a standard Tesla Model 3 holding an 80 kWh lithium-ion battery will produce 2,400kg to 16,000kg of CO2. The difference in emissions lies in the type of fuel burnt – gas or coal for example. Coal produces much more pollution. This is on top of other forms of pollution such as water pollution, but let us stick to air pollution for now. As an average, we will assume a 9,200kg of CO2 emissions per car battery produced.

Emissions of recharging batteries
According to the International Energy Agency (IEA), the average carbon intensity of electricity generated is 475g of CO2/kWh. To fully charge a 80 kWh Tesla Model 3 will emit 28kg of CO2. One thing many fail to consider is that the charging of the battery itself requires electricity generated from the burning of fossil fuels. Of course, we can get electricity from solar, wind, geothermal, hydroelectric and even nuclear power, but such renewable energy is not sufficient to sustain the needs of human civilisation as a whole. Most of our energy is still obtained from the burning of fossil fuels, which releases CO2.

A Tesla Model 3 is expected to travel 3.33 to 4.17 miles per kWh of electricity. We will take the average and assume 3.75 miles = 6.04 km per kWh of electricity.

Average Lifespan Of A Electric Car Battery
There are no official sources for it, but a search across Google on different sources came up with a low of 65,000 miles to expert views of 200,000 miles for its lifespan. MIT assumed a lifespan of 12 years at 12,500 km per year, so I will take their figure as a reference. This works out to be 150,000 km worth of distance travelled over the lifespan of a car battery. A reasonable figure, considering that like human lives, batteries slowly waste away until the point they become unusable.

Consolidation Of Data
With so much numbers above, let us do a simple consolidation.

Gas-powered cars: 251g of CO2 per kilometre travelled.

Emissions per car battery produced: 9,200 kg of CO2 for a 80 kWh lithium-ion battery
Average emissions required to produce electricity: 475g of CO2/kWh
Average lifespan of a car battery: 150,000 km
Distance travelled per kWh of electricity: 6.04 km
Emissions per km travelled = 475 / 6.04 = 78.64g of CO2

Comparing Emissions Till End Of Lifespan
We assume that a gas-powered car travels the same distance of 150,000 km as an EV before the battery needs to be replaced.

Gas powered cars: 150,000 km x 0.251 kg of CO2 = 37,650 kg of CO2 produced.
EV: 9,200kg of CO2 for battery production + (0.07864 x 150,000) for emissions over lifespan = 9,200kg + 11,796 kg= 20,996 kg of CO2

We can conclude that with gas-powered cars we will burn approximately 37,650 kg of CO2. With electric vehicle we can expect only 20,996 kg of CO2. If we take the most polluted of car battery manufacturing as a reference we will get 16,000 kg for battery manufacturing + 11,796 kg over lifespan = 27,796 kg of CO2 for EVs.  

From the numbers we can expect a more realistic 44% reduction in emissions and a not so good case of 26% reduction if the batteries were made in a very polluted manner. At this point we can make a small conclusion that EV does make the environment greener.

Battery Disposals
Once a battery reached the end of its lifespan, or when an EV gets scrapped, the battery disposal remains a problem. With an increasing higher rate of adoption for electric vehicle, we should expect an exponential increase of waste battery in a few years. Batteries as we know in our daily disposal, has to be treated differently because it can be toxic and can catch fire. Currently there are many firms and initiatives aiming to solve this problem, but none has shown any actual results yet, probably because the industry is still very new. Yet this is a big market with a huge potential. I have faith in the machineries of capitalism to sufficiently resolve this issue. If there is money to be earned, humans are just as likely to save the Earth as they destroyed it. The only difference is which is easier and faster to earn a bigger sum of money.

EV is not totally pollution free. It is just that the pollution happens backend where most people do not see. From water to air pollution as well as the disposals of the batteries, we should expect damage to the environment. However, the numbers do show that the worst and most polluted of car batteries is still significantly better than using gas to power up our cars. We can safely consider this to be a step towards a greener Earth which mankind desperately needs before we wipe ourselves out.

That is why electric vehicles has a future, and that is why certain governments around the world are jumping on it. In the future, those who cannot keep up with times will lose their jobs. And in the name of protecting our Earth, countries will clamp down on each other. Between reaching out to the stars and dying a violent death, mankind has to decide what to sow and in return, our descendants will harvest the fruits either of our labour or of our sins.

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- Resources Price
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