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Green e vehicle case study
The global production of cars in 2014 was 68 million per year, growing at 2.5 % per year. Cars account for 75% of
production of motor vehicles and are responsible for about 20% of all the carbon released into the atmosphere1
.
National governments implement policies to reduce this source of emissions through taxation and incentives.
One of the incentives is to subsidize electric vehicles (EVs).
From a materials point of view, the major differences between electric and internal combustion (IC) cars are the
replacement of the IC engine with electric motors that, at present, use Neodymium-Boron permanent magnets
and the replacement of gasoline or diesel fuel by batteries. It is estimated that the global production of electric
cars – either hybrids (HV), plug-in hybrids (PHV), or fully electric (EV) – will exceed 16 million per year in 2021
and will account for 20% of all vehicles manufactured2
. EVs, particularly, are seen as the way to decarbonize road
transport. To meet emissions targets, France, Germany and the UK want 10% of all car sales to be fully electric
vehicles by 2020. Is this a realistically achievable sustainable development on a global scale?
Background information
• Today’s electric cars have 16 kWh batteries and a claimed range of up to 100 km between charges.
• An EV with this range requires about 1.5 kg of Neodymium for the motors3
and 7.3 kg of lithium, (equating
to 0.46 kg Lithium per nominal kWh) for the rechargeable batteries4
.
• The at-wheel energy required to propel a small car is between 0.6 and 1.0 MJ/km (0.17 and 3 kW.hr/km)5
.
• Delivered electric power from a gas-fired power station has a carbon footprint of 500 g/kW.hr, or 140 g/MJ6
;
that from a coal fired power station has larger carbon footprint
4 Tahil, W. (2010) “How Much Lithium does a LiIon EV battery really need? www.meridian-int-res.com and http://www.google.co.uk/
search?sourceid=navclient&ie=UTF-8&rlz=1T4ADBR_enGB321GB323&q=how+much+lithium+is+in+a+battery
5 Telens Peiro, L. Villalba Mendez, G. and Ayres, R.U. (2013) “Lithium: sources, production, uses and recovery outlook” JOM Vol 65, pp.
896 – 996.
6 See, for example, www.defra.gov.uk/publications/files/pb13773-ghg-conversion-factors-2012.pdf Table 3c
4 © 2021 ANSYS, Inc. GRANTA EDUPACK
This resource follows the five-step method, which is simply explained below and explained in detail elsewhere.
• What is the prime objective? What is its scale and timing? What is the functional unit?
• Who are the stakeholders and what are their concerns?
• What facts will be needed to enable a rational discussion of the proposal?
• What, in your judgment, is the impact of these facts on Natural, Manufactured, and Social Capitals?
• Is the proposal a sustainable development? Could the objective be better met in other ways?
Where can Granta EduPack help with Fact Finding?
The Materials data-table has records for permanent magnet and battery materials
such as lithium that include data for price, embodied energy, carbon and water
footprints and recycle fraction.
The Eco Audit Tool allows a fast comparison of the carbon footprint of the alternative
material choices.
The Nations of the world data-table (Level 3 Sustainability) contains records for the
environmental, economic and societal statistics of the nations from which elements
are sourced.
The Graph facility of Granta EduPack allows data to be plotted as property charts,
annotated, and saved to Word Documents.
The Regulations data-table (Level 3 Sustainability) includes records for regulations
relating to transport, batteries and recovery and recycling of vehicles.
The Power Systems – Energy storage data-table (Level 3 Sustainability) has data for
battery types and their characteristics
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Electric Cars– Example of Assessment
The number of the sections corresponds to that of the 5 steps of the analysis. Granta EduPack databases help
with fact-finding in ways described int he handout for this case study.
Step 1: the objective, size, time scale, and functional unit
• Objective: the de-carbonization of road transport
• Size scale: 10% of existing car production globally, equating to 8 million cars per year
• Time scale: by 2020
• Functional unit: 8 million cars
This immediately poses some critical questions:
• Electric vehicles are charged from the National Grid, at present gas or coal-fired in most countries. Do fully
electric vehicles really reduce emissions?
• Is there sufficient over-capacity in electric power generation to cover charging of electric vehicles increasing
in number by 10% per year?
• What materials are used in electric cars that are not used in today’s conventional vehicles? Today’s EVs use
lithium-ion batteries to drive permanent-magnet electric motors; the motors use neodymiumboron alloys
for the magnets. Is the global production of lithium and neodymium sufficient to cope with the production
of 8 million cars per year?
These are questions to research in Step 3, Fact-finding.
Step 2: stakeholders and their concerns
The national press reports the views of government, industry and the public about electric cars.
Here are seven examples
- In his 2011 State of the Union address, widely reported, President Obama called for putting 1.2
million electric vehicles on the road by 2015. This equates to 10% of the annual car sales in the
US. Today, in 2016, it is clear that this wish was not fulfilled. - “Bloomberg Endorses Preparing Parking Spaces for E.V.
Charging.” (The New York Times, 14 February 2013). The
mayor says he wants New York City to be a “national
leader” in electric vehicles - “That Tesla Data: What It Says and What It Doesn’t.”(The
New York Times, 14 February 2013). The New York Times
reporter responsible for covering energy, environment
and climate change discovers the hard way that the
claimed range of electric cars is sometimes a little
overstated. - “CO2 emissions 0 g/km.” (The London Times, 24.February
2013). Advertisement for Nissan Leaf. - “Are electric cars bad for the environment?” The
Guardian 4 February 2013) Norwegian academics argue
that electric cars can be more polluting than claimed7
. - “Leaf stalls” (The London Times 5 March 2013). Nissan
admits that customers hesitate to buy its Leaf EV because
of price and range anxiety. - “Biofuels could cut CO2 ‘cheaper than electric cars’” – Businessgree.com report the conclusion of a new
(2013) report commissioned by oil giant BP, which part-owns the Vivergo ethanol plant8
.
7report-biofuels-could-cut-co2-cheaper-than-electric-cars
Figure 1: Stakeholder interest and influence
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These reports give an idea of the controversy surrounding electric vehicles. They also give an insight into the
stakeholders and their concerns and relationships (Figure 1). Among them are those listed in Table 1.
Table 1: Stakeholders
Are these concerns valid or (if they are not) can they be refuted? That is a further job for Step 3, Fact finding.
Step 3: fact finding9
What information is needed to support or refute the claims made for electric cars and the concerns
expressed about them? What additional facts do we need for a rational discussion of the Prime
Objective – 10% of cars fully electric by 2020? These questions are explored in the sections below.
Energy and power. Batteries are heavy. Weight is minimized by selection the battery with the highest energy
density. Figure 2 plots the energy density for energy-storage systems10. Lithium-ion batteries out-perform all
other battery types, although their energy density, 0.6 MJ/kg, is still a factor 75 less than that of gasoline or
diesel fuel. The at-wheel energy required to propel a small car is about 0.6 MJ/km. Thus the battery weight per
unit range is roughly 1 kg/km. An acceptable range of 500 km (300 miles) would need a battery weighing half a
tonne and costing, at today’s prices, about $50,000.
There are about 1 billion cars on the world’s roads. If 10% of these were EVs, driven 17,000 km (10,000 miles)
per year, each consuming 0.6 MJ/km, they would draw 108 x 0.6 x 17,000 = 1012 MJ / year from the national
grid. An average power station produces 4 x 1010 MJ / year, so 23 additional power stations would be required
to charge the cars. A country the size of the UK, France or Germany would require at least one additional power
station to cope.