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Carbon footprint of electric vehicles./?/!

Updated: Sep 2, 2019

There has been increasing concerns in our communities on the carbon footprints associated with electric vehicles and renewable energy technology. These concerns are largely based on the energy-intensive processes involved with the extraction and mining of rare earth materials, and its subsequent use in vehicle production stage. In addition to carbon footprint, significant environmental pollution has also been concerning.


Circular economy is the new buzz word which is popping up time and again. In the current NZ trajectory to transition into a circular economy, the value of the materials and its resulting products are expected to be kept as high and as long as possible. This encourages our economy to pursue the development of a product from a sustainable perspective. Additionally, with the inception of 17 sustainable development goals (SDGs), the environmental impacts of new and emerging technologies are considered to be significantly less as compared to the conventional technologies which were introduced in the linear economy period.




Adapting to renewable energy sources or initiating projects for a more sustainable lifestyle cannot entirely be free from GHG related emissions. There will be a toll on us and the environment. But the question is have we understood how to assess the life cycle impacts of newer sustainable technologies to judge whether they are truly sustainable?


Environmental impact of a product’s life cycle assessment: an electric vehicle perspective


Life cycle assessment (LCA) in the context of renewable technology refers to assessing the environmental impact linked to all the steps of a product’s life. This means assessing all stages in its production right from its raw material extraction, processing of raw materials to finished products, its everyday usage and finally safely discarding the product once it reaches the end of life. Understanding the life cycle assessment of the product in question helps us to understand its impact on climate change, human health and our natural ecosystem.


This blog intends to only summarise the key points highlighted from the extensive research work compiled and assimilated by the European environment agency [1] on life cycle assessment of electric vehicles.


In the European Union (EU) transport sector accounts to 80% of the total GHG emissions, hence EU is committed to reducing GHG emission to 40% by 2030. Though the policy may seem ambitious, it has certainly sent a strong message to all sectors of the society to find ways to transition to zero-emission systems. This is reflective of the fact that the global market for electric cars has seen 50% increase in electric cars from 2016 to 2017, which accounted to 3.1 million electric cars on road in 2017 [2]. In 2018 the global EV transport consumed around 58 terawhatt-hours (TWh) of electricity and displaced the consumption of 36 million tonnes CO2 equivalent (Mt CO2-eq) [2] .


There are currently five types of electric vehicles:

1. Battery electric vehicles (BEVs) solely depend on the stored electricity in batteries to power the electric motor.

2. Plug-in-hybrid electric vehicles (PHEVs) are powered by both electric motor and by an internal combustion engine. These two powering systems can work together or separately.

3. Range extended electric vehicles (REEVs)- are a type of hybrid systems where the range extenders, which can gasoline driven internal combustion engines or hydrogen driven fuel cells, generates electricity to power the vehicle’s electric motors or recharges its batteries when it is low.

4. Hybrid vehicles- are quite similar to PHEVs where they are powered by both internal combustion engines and electric motors. They differ from PHEVs on the basis that are charged only from gasoline and cannot be charged from electricity. They, however, capture energy when braking to charge their batteries. This regenerative braking converts kinetic energy into electricity. Generally, in conventional vehicles, this kinetic energy is normally wasted.

5. Fuel cell electric vehicles (FCEVs)- are entirely powered by electricity just like BEVs, but differs with respect to how it stores energy. FCEVs have a separate tank filled with Hydrogen. A fuel cell (a device that converts chemical energy into electrical energy) combines the Hydrogen in the stored tank with Oxygen from air to produce electricity which then powers the electric motors just like the BEVs. The byproduct of the reaction is water.


Much of the life cycle assessment reports are on a type of electric vehicles called battery electric vehicles given their popularity in the current market. Thus, the following sections only delve into life cycle assessment of battery electric vehicles and how they compare with the conventional internal combustion engines vehicles (ICEVs) .


Environmental impacts are generally grouped under the following categories:

1) Climate change

2) Health impact

3) Ecosystem impact


1) Climate change impacts:

  • Use phase: Overall, across its life cycle, BEVs offers significantly less GHG emissions as compared to ICEVs during its in-use phase. However, a key assumption made in such a comparison is that the electricity required to run BEVs are from renewable sources.


“BEVs charged with electricity generated from coal currently have higher life-cycle emissions than ICEVs, whereas the life-cycle emissions of a BEV could be almost 90 % lower than an equivalent ICEV (IEA, 2017a) using electricity generated from wind power.”-TERM 2018

  • Mining and production phase: Electric vehicles tend to use more copper (almost four times more than ICEVs) and some nickel for their battery and electric traction motor as compared to conventional vehicles. These materials use up intense energy for the purpose of extraction and refining.

As a way to achieve better fuel efficiency and handling, “lightweighting” the car is an essential concept in manufacturing new electric vehicles. As a consequence of moving towards lightweighting the car there will be an increased use of carbon composites and aluminum in the future. This will lead to increased energy consumption. GHG emissions from raw material extraction and transforming the raw materials into transformed products is greater for BEVs than ICEVs equivalents. Further research and development is required for potential reuse and recycling of vehicle components.


2) Human health impacts

  • Mining and production phase: A key health issue raised is the toxic emissions resulting from mining and processing of metals such as copper and nickel. Such impacts largely occur in countries where health and safety precautions are less stringent than elsewhere. As a result of less stringent measures, these toxic elements are likely to enter water bodies and exacerbate the toxic health effects locally. Additionally, the raw materials are restricted to a few regions in the Earth's crust, and thus may bring in the monopoly of the supply chain. For example, China currently accounts for 70% of the global supply and 62% of European Union supply of critical raw materials. Being such a significant actor in supplying critical raw materials, China’s dominance allows it to control the price of materials, thus creating supply and economic risk.


  • Use phase: A key point to remember from human health perspectives, are the improved local air quality owing to zero exhaust emissions, e.g., NOx and particular matter. In terms of noise pollution, only the use-stage of BEVs has been assessed. Significant differences in noise pollution does depend on vehicle’s speed. When BEVs are driven at residential speed limits, their noise level is significantly less compared to ICEVs. However, at higher speeds, such a difference is unlikely to occur.


  • Recycle phase: Recovery of key rare earth elements and critical raw materials at the end of life of electric vehicles can significantly reduce the environmental and economical impacts of mining. For example, when Li-ion batteries reach their end-of-life-stage, they can be used for backup energy storage from renewable. Nissan recently has initiated the reuse of Li-ion batteries as replacement packs for first-generation Nissan LEAF vehicles. There is, however, a lot of uncertainty as to what extent sustainability can be achieved at this stage, as not all the raw materials can be reused, and thus may have the potential to end up in landfill.


3) Ecosystem impacts


  • Mining and production phase: Freshwater ecotoxicity and eutrophication (def: process of chemical run-offs from land causing dense growth of certain plants and blocking sunlight into the water body) seems to be of greater problem for BEVs than ICEVs as a consequence of mining raw materials. In addition to eutrophication, terrestrial acidification (def: a fall in soil acidity by atmospheric deposition of sulphates, nitrates and phosphates, thus leading to loss of biodiversity and productivity) is another harmful impact on our ecosystem where SO2 generated from battery production and non-renewable energy generation leach into the soil. There are conflicting views on which vehicles systems (BEVs or ICEVs) have increased terrestrial acidification potential, where one suggests the life cycle impacts of both are similar and the other report that BEVs might have a greater impact.

Loss of biodiversity of both flora and fauna on both land and aquatic bodies is another major side effect from the mining and production phases. The intricate interdependence of humans with the natural ecosystem is a highly complex process and any interference can have cascading irreversible damage.

The toxic effects of extracted elements into the environment has the potential to be neglected due to its fairly low concentrations, immobility (Def: the inability of toxic elements to spread in soil, water or air) and insolubility (Def: the inability of a substance to be completely dissolved or mixed in the environment). However, the low concentrations of such chemicals can end up in terrestrial life owing to the phenomenon of biomagnification also known as bioaccumulation (Def: the increase in the concentration of industrial chemicals as it travels up the food chains). Humans happen to be on top of the food chain and bear the maximum impact of biomagnification.


Overall


The degree of impact that BEVs has on both our natural ecosystems and human toxicities depends on several variables such as electricity generation mix, promotion of reuse and recycle, vehicle design, emphasis on maximising vehicle range and the strength of consumer activism.

“Despite its drawbacks, particularly in the mining and production phase, electric vehicles are crucial in transitioning our society to a zero-emission future."

The power of consumers to choose products and services which are ethically produced and those that are environmentally friendly plays a huge role in influencing sustainable business practices. In order to strengthen consumer activism, careful analysis of the life cycle assessments of product/ technology under question will help in finding loopholes and identify areas in which consumer activism needs to be targeted.


Despite its drawbacks, particularly in the mining and production phase, electric vehicles are crucial in transitioning our society to a zero-emission future. On a per kilometre basis, CO2 and air pollutant emission of BEVs are significantly lower compared to ICEVs during its use phase and this happens to be the driving force to expand EVs fleet in our communities.


Therefore, coming back to the original concern regarding carbon footprint and environmental impact from electric vehicles, consumer activism thus needs to be fine-tuned to draw the attention to the following issues:


1) Improving the health and safety standards during mining and processing of elements required for electric vehicles. These include advocating for the sustainable working conditions such as adequate ventilation, heighten awareness of safety precautions among workers and proper use of protective equipment.

2) Choosing electric vehicles which use lower quantitates of raw materials. This would also include selecting electric vehicle manufactures who are conscious of life cycle impact of their products, and are willing to provide information regarding their supply chain to the customers upon their request.

3) Promoting the production of batteries which have lower impact on the environment and can be easily recycled to extend its life time.

4) Promoting the production of electric vehicles which are independent from battery technology such as Hydrogen fuel cell. Unlike the fossil fuel dependent internal combustion vehicles which have dominated transport industry, the energy to power our transport has to be sourced from variety of renewable resources so as to prevent the technology from monopolising the transport industry again.


References:

1) European environmental agency, 2018, Electric vehicles from life cycle and circular economy perspectives TERM 2018: Transport and Environment Reporting Mechanism (TERM) report (https://www.eea.europa.eu/publications/electric-vehicles-from-life-cycle) Accessed on 15 Aug 2019.

2) International energy agencies, 2018, Global EV outlook 2018, (https://webstore.iea.org/download/direct/1045?fileName=Global_EV_Outlook_2018.pdf) Accessed on 20 Aug 2019

3) European parliamentary research service, 2019, Electric road vehicles in the European union: Trends, impacts, and policies (http://www.europarl.europa.eu/RegData/etudes/BRIE/2019/637895/EPRS_BRI(2019)637895_EN.pdf) Accessed on 2 Sept 2019


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