battery electric vehicles
BEVs (battery electric vehicles)
Table of Contents
General
Here are the definitions of some common acronyms used in electric vehicles articles:-
- BEV (battery electric vehicle):\\[1pt]A pure battery electric vehicle with no other sources of energy, other than the battery.
- PHEV (plug-in hybrid electric vehicle):\\[1pt]A vehicle containing a drive chain battery and electric motor, which can be recharged from mains electricity, but which also contains a fossil fuel engine, such as a petrol or diesel engine. Typically the battery size is sufficient to allow some tens of miles using battery power alone, before either recharging or automatically starting the petrol or diesel engine.
- PEV (plug-in electric vehicle):\\[1pt]“PEV” describes either a BEV or a PHEV. It is a vehicle which can operate on electric drive alone for at least a few tens of miles, prior to recharging
- NEV (new energy vehicle):\\[1pt]“NEV” is normally used in China to denote a vehicle powered by a source other than a petrol or diesel engine (which were regarded as the “old” energy vehicles, common at the end of the 20th century). It includes BEVs, PHEVs, and HFC vehicles (see below)
- HFC (hydrogen fuel cell) vehicle:\\[1pt]A vehicle with an electric motor, powered by hydrogen via a set of hydrogen fuel cells. It typically also includes a small battery. The hydrogen fuel cells are expensive, and normally there are insufficient to provide enough power to allow the vehicle to accelerate at a reasonable rate. So the battery provides additional power to boost the acceleration. The hydrogen fuel cells recharge the battery when the overall power demands are not so great.
- ICE (internal combustion engine) vehicle\\[1pt]Usually a fossil fueled vehicle, such as a petrol (US gas) or diesel engine vehicle. The term “ICE” can also include vehicles powered by compressed natural gas or other fossil fuel gases. Strictly, it could also include ICE vehicles fueled with green hydrogen or other types of hydrogen, though such vehicles are not common.
From one battery charge, BEVs will have ranges from, perhaps, 50 miles (80 km) up to a few hundred miles, perhaps 500 miles (800 km).
The lifetime emissions of a BEV when powered by an average US or European grid are considerably lower than for any comparable fossil fuel vehicle. As an example, the average UK fossil fuel car in 2019 had total life cycle emissions that were around 3 times higher than for a Nissan Leaf with a 40 kWh battery.
Apart from the battery, the rest of an electric vehicles generally has similar production CO2 emissions to those from a comparable fossil fuel vehicles. Battery production CO2 emissions must be added to the emissions from producing the rest of a BEV or PHEV.
Battery production CO2 emissions split into:-
- emissions from the mining of battery raw materials
- emissions from the processing of raw materials into complete battery cells and then battery packs
To reduce the CO2 emissions from mining requires specifically addressing this issue, and there may be more progress over time.
However, the CO2 emissions from the battery production plant reduce automatically as the local electricity supply gets greener. The plant can also specifically contract for electricity with zero operational CO2 emissions, and can design the processing to minimise the energy used from processing, and the raw material wastage.
CATL has constructed a certified zero emissions battery processing plant in Yibin, Sichuan Province, China. Local, zero operational CO2 emissions, hydroelectric power mainly powers this CATL processing plant.
Typically, production of lithium ion batteries in a net zero emissions processing plant results in total battery pack CO2 emissions of around 60 kg/kWh from materials mining operations.
The following table gives an indication of the average CO2 savings per year from a BEV in various regions and countries:-
| Region | Year | Grid CO2 gm/kWh | Average distance per year | BEV miles/kWh | New FF avg CO2 gm/km | CO2 saving tonnes/year |
|---|---|---|---|---|---|---|
| USA | 2021 | 389 | 13,500 miles 21,600 km | 2.5 to 4.0 | 217 | 4.7 – 1.3 to 2.1 = 2.6 to 3.4 |
| UK | 2023 | 146 | 7,500 miles 12,000 km | 3 to 4.0 | 144-160 | 1.7 – 0.3 to 0.4 = 1.3 to 1.4 |
| EU-27 | 2021 | 280 | 7,500 miles 12,000 km | 3 to 4.0 | 123 | 1.5 – 0.5 to 0.7 = 0.8 to 1.0 |
Within the averages there will be considerable variation in miles driven.
The different USA state and EU country grid have a wide variety of carbon intensities (CO2 gm/kWh). So the ranges and averages are just an indication. Different BEVs have different efficiencies, usually in the range of 2.5 to 4 miles/kWh. The USA vehicles tend to be bigger and less efficient.
Here is a 2022 list of EVs and efficiencies in Wh/mile (rather than miles/kWh). For a 75 kWh battery with production emissions of 60 kg/kWh (which means a net zero battery processing plant), the production emissions would be 4.5 tonnes. Thus the CO2 breakeven times between purchasing a BEV with a range of 250-300 miles and buying a pure fossil fuel car are around a couple of years in the USA, 4 years in the UK, and 5 or 6 years in the EU.
These calculations ignore the rapid country grid carbon intensity reductions which will take place in the EU and UK country grids over the next few years, which will bring these breakeven times down.
Charging of EVs can use either AC or DC.
AC charging supplies the local mains AC voltage to the BEV, which uses its own charging circuitry to convert this to the DC voltage required by the battery (typically 400V to 1,000V). A single phase AC mains supply restricts AC charging to 7 kW. But a three phase AC mains supply allows AC charging at up to 11 kW, and sometimes 22 kW .
The simplest method of AC charging uses a lead which plugs into a local domestic socket. The charging AC power is typically 2.3 kW for 230 volt domestic supplies, but sometimes 3 kW.
DC charging always uses a charger external to the EV. DC chargers supply the voltage and current required directly by the BEV in its current state of charge, completely under the control of the BEV. The power supplied to the EV battery is a maximum or either the power the external charger can deliver, at the voltage requested by the car, or, if lower, the power the BEV battery can take at its charge state at that point in time.
As of May 2023, External DC chargers installed vary between 60 kW and 350 kW for current light BEVs (cars). Tesla has installed a few 1 MW chargers in the USA so far for Tesla semi class 8 trucks, and has confirmed these can also be used by the forthcoming Tesla Cybertruck..
As an alternative to plugging in, wireless inductive charging can be used to charge BEVs.
Inductive charging uses a transmitter wire loop in a pad on the surface, or installed underneath the parking space, and a receiver wire loop on the bottom of the BEV. There must be some means to enable the driver to align the two loops. The two wire loops act as a high frequency transformer to transfer power from the transmitter to the receiver. With suitable electronics at both ends, a V2G (“vehicle to grid”) power transfer (the other way) can also take place.
The size of the loops, and the frequency of the AC current in the transmitter loop, limit the power transferred. The development of fast, high power silicon carbide switches enables transfers of up to 500 kW, with no more than 1-2% of additional losses due to the wireless induction transfer, when compared to a cable transfer.
As well as the convenience for private BEV charging at home, inductive charging would be very useful for electric taxi ranks and fast intermittent charging of electric buses while stationary at bus stops.
At present only one US EV (the BMW 530e hybrid sedan) has a manufacturer’s option for inductive charging. But inductive charging can be fitted by a third party to most BEVs. The transmitter and receiver have to be compatible.
Normally, the inductive charging receiver interfaces to the BEV DC charge socket. For inductive charging via the DC charge socket, the BEV controls the voltage and current of the DC charging process. An AC charging port normally accepts standard mains voltages, and provides only lower power charging.
The above description relates to “static” inductive charging, where the BEV is stationary.
There are also proposals for “dynamic” inductive charging of a moving BEV, but it is not clear that there is a big demand for charging moving BEVs. The US state of Michigan has a partnership with Electreon to provide dynamic (on the move) wireless EV charging on a one mile stretch of road in Detroit as a trial.
A survey showed that there is considerable interest in wireless inductive charging in the USA.
A BEV with a 300 mile range, and a 30 mile daily round trip commute most likely has a week or so of flexibility in between full charges. Smart charging involves a direct or indirect negotiation between the BEV and the grid to exploit the available charging flexibility to:-
- charge the BEV outside peak demand hours to avoid overloading the transmission and distribution grids with EV charging demand
- charge the BEV at times of surplus wind and/or solar power
- not charge the BEV at times when power is scarce, whenever much higher wind and solar output are forecast within the BEV smart charging flexibility window.
Most of the smart charging accounts are expected to be with retail energy (electricity) suppliers.
Some electric vehicles may not be able to take full advantage of smart charging at particular times, as follows:-
- Many buses, coaches, taxis and trucks may travel on schedules which allow only limited flexibility in charging. There may be flexibility in the hour of charging overnight, but it might be essential that they are fully charged by the start of their working day.
- Vehicles, normally having a high degree of flexibility in when to charge, may be scheduled to make long journeys, perhaps immediately, or perhaps on the following day. These vehicles may require a full charge, either as fast as possible, or by a short term deadline.
- Vehicles requiring charging on a long journey must usually be fast charged immediately, though not necessarily to 100%.
Smart charging apps must allow:-
- Specification of a minimum charge level by the start of use on each day (which might be different on weekdays vs weekends).
- An immediate charging option
- An option for a full charge by a particular deadline
Some of these options might be specified in a calendar for the BEV driver, to which smart charging would have access.
The biggest benefit of smart charging would be a much lower electricity price during normal, flexible, smart charging. Electricity for charging outside the normal smart charging arrangements would cost more, perhaps on a scale which rises with scarcity of net electricity supply (supply less projected load).
One issue is to ensure that shared apartment off-street parking areas can be fitted with the required number of chargers. UK and Germany, and many other countries have laws which ensure new and refurbished buildings, with more than a certain number of parking spaces, have to have one or more bays fitted with a charger. Such laws don’t address the number of drivers with no off street parking, but, at least, ensure that private chargers can be installed in suitable existing locations.
EVs can often be parked on a public street, immediately outside the owner’s house or flat. There is no clear answer as to whether these can be charged via cables over public walkways (pavements/sidewalks), from sockets in the owner’s home. In most places, it is not legal to string a long extension cable to the car, which passes over public land. There are technical solutions to avoiding trip issues, such as cutting a thin channel to feed a cable, which can be shaped to avoid a trip hazard. For many, there is no guarantee they can park immediately outside their home, on a public street. Perhaps a consensus, or new technology, will emerge on this issue.
Statistics for the limited number of countries covered below show that 20% or less of eventual BEV drivers will have to rely mainly on street or other public charging locations while resident at home.
United States
PWC cites a US DoE estimate that up to 80 to 90% of BEVs will normally be charged overnight at home or at work. I can’t find the source DoE document. These vehicles will sometimes need fast charging at road services on long journeys, or need charging at a destination.
The ICCT (International Council on Clean Transportation) July 2021 report Charging up America [Fig 5] 2030 estimate is that 69% of electricity US EV charging will be supplied through off street chargers at home (59%) or at work (12%). Thus 29% must be supplied by public charging, of which 20% will be supplied through public fast chargers and 9% through public level 2 chargers (5 kW to 7 kW). The implication in the report is that the 2030 figures would represent the situation when all US vehicles are electric, but it is not explicitly stated.
If 10%+ of charging is through fast chargers, by BEVs which are more normally charged off street at home or work, then the percentages are consistent with the US DoE estimates above.
Ensuring that chargers can be fitted in shared parking for apartments and condominiums may be an issue in the USA, as a legal right to charging at shared private parking may have to be established in each US state individually.
England (UK)
Roughly 20-25% of UK drivers would not be able to charge off street at home or at work. The English Housing Survey Data [DA2201] shows 67% of English homes have either a garage (35%) or other off-road parking (32%).
Car owners will tend to choose homes with off street parking. The majority of those who do not own a car will tend to live in flats/apartments in the large cities with good public transport. The implication is that significantly more than 67% of eventual BEV drivers will have off street parking at home on which a private charger can be installed.
PWC stated elsewhere (I can’t find the reference now) that around 10% of drivers who could not charge privately at home would be able to charge privately at work.
MotaClarity (a website for disabled drivers) has various suggestions as to how to charge a BEV parked on the street outside the owner’s house on its web page “How Do People With No Driveway Charge An Electric Vehicle?”.
A BEV has high efficiency, of up to 85-90%, compared to fossil fuel engine engine efficiencies in the range of 20 to 37% for petrol and 30-41% for diesel.
BEV efficiency comes from the combination of the following:-\\ \\
- Electric motors can achieve efficiencies well in excess of 90% for a wide range of operating conditions and above 95% for normal operation at a steady BEV speed. See “Electric motor efficiency” below.
- BEV batteries can have a round trip efficiency (energy out vs energy in) of over 90%. BEVs battery efficiency is highest if a BEV is slow charged (usually via AC, rather than DC), and the maximum state of charge is no more than 80%, unless preparing for a long trip. See “Efficiency” in the “Battery theory” web page.
- BEVs usually have regenerative braking, converting the kinetic energy of motion back to electrical power, which is sent back to the battery, whenever the driver presses the brake pedal. Provided braking is not emergency hard braking (using brake pads and discs), 60% of more of the kinetic energy of motion can be recovered
- BEVs tend to be specifically designed to achieve as low a weight as possible and as high an efficiency as possible. As an example, some BEVs now use heat pumps for heating the interior, which is three times as efficient as electric resistance heating.
The characteristics above translate into a typical efficiency for electric cars in the range of 3 to 4 miles/kWh (4.8 to 6.4 km/kWh). In the USA, some private vehicles are much bigger and heavier. These bigger, heavier vehicles might achieve only 2.5 miles/kWh (4 km/kWh), and sometimes even less.
Here is a link to the ev-database list which contains a figure for EV efficiency, expressed as Wh/mile. Divide 1,000 by the Wh/mile figure to translate into miles/kWh. To get km/kWh multiply the result by x1.6.
Note that the ev-database list likely contains official efficiency and range figures result from standardised testing. These will not represent the efficiency and range obtainable on a specific journey, under specific driving conditions (such as when heating or air conditioning is active), nor representing the driving style of a particular driver. So they should be treated as indications only.
An example of an electric motor efficiency chart is below, for the BorgWarner HVH250-115 SOM electric motor. The performance section below includes the torque and power charts for this motor.\\ \\
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Note the large area of operating characteristics (various shade of red but not orange) in which the motor will operate at over 90% efficiency, and a significant area in which it achieves 95% efficiency.
Electric vehicles have an inbuilt performance advantage over fossil fuel vehicles. An electric motor delivers maximum torque from zero revs upwards, dropping only as the applied voltage is not high enough to fully overcome the back EMF (electromagnetic force = back voltage of the motor opposing the applied voltage as a result of the speed at which it is spinning).
SOM refers to the fact the electric motor is single wound. Dual wound electric motors can run at more than one speed when fed with AC power at a fixed frequency (such as 50 Hz or 60 Hz).
The torque is almost constant until the elbow in the curves. The maximum RPM for the flat torque region depends on the driving voltage, dictated by the battery voltage.
The descending curves on the right of the elbow of the torque curve are a result of the fixed battery voltage limit. The motor always acts as a generator to produce a voltage (back EMF as above) dependent on the motor speed. After a certain motor speed, the battery does not have enough voltage to be able to push maximum current through the motor, so the torque drops, and the power produced by the motor is no longer proportional to the speed of the motor, as in the curves on the following chart.
Torque determines acceleration.
ICE (internal combustion engine) vehicles don’t develop maximum torque until the motor has reached a few thousand RPM. Thus a fossil fuel vehicle needs gears (either automatic or manual).
The chart below, from Monceaux Automobiles (who convert classic Mercedes to electric drive), shows the torque from ICE vehicles vs BEVs of a similar maximum power.
You can see that a BEV with a lower maximum power electric motor is likely to out-accelerate a fossil fuel car with a higher maximum power engine. Hence my lowly 2015 Nissan Leaf beats almost any fossil fuel car, short of a supercar, away from the front row of the traffic lights in London. My 80 kW Leaf seems to be 40 yards ahead before a fossil fuel car starts to develop any significant torque, without exceeding any speed limit.
However, if both vehicles are doing 40 mph and suddenly accelerate, a fossil fuel car with a higher maximum power than my Leaf will always reach 60 mph first, as the torque from the Leaf electric motor will not exceed the fossil fuel engine at any point between those two speeds.
Any Tesla will leave both cars standing, however. The Tesla model S Plaid variant is the fastest production electric car and can do 0-60 mph in 1.99 seconds. That is, it accelerates faster (1.37 g) on the road than its vertical acceleration if you drive it off a 250 foot vertical cliff (0-60 mph in 2.7 seconds, terminal vertical velocity 86 mph). The man who drove off the cliff in a Tesla model Y, miraculously, survived with severe bruising, as did his wife and two children who were also in the car. Do not try this at home.
The technical way to beat an electric car from a standing start with a higher powered petrol or diesel car would be to disengage the clutch, wind the engine up to the revs for maximum torque, then to slip the clutch when the lights change. Doing this frequently is not recommended.
BEVs tend to be a little heavier than comparable fossil fuel vehicles. You would thus expect faster tyre wear, a shorter tyre lifetime, and higher particulate emissions from the tyre wear.
However, BEVs almost invariably have good traction control, giving smooth acceleration and little chance of locking the wheels during braking. Both of these help to reduce tyre wear.
Moreover, most tyre makers, such as Goodyear, make some tyres which are specific to BEVs. They use harder wearing compounds and are more rigid, which reduces flexion and gives a lower rolling resistance, thus improving efficiency. This leads to improved tyre lifetime for BEVs.
According to Kwik Fit (tyre fitting specialists), who should probably be regarded as the subject matter experts, a BEV-specific tyre fitted to a BEV has a 30% longer mileage lifetime than a conventional tyre fitted to a comparable fossil fuel vehicle.
BEV-specific tyres are more expensive than conventional tyres, so should provide improved performance in some areas.
As a result, BEVs with BEV-specific tyres are going to cause lower particulate emissions than comparable fossil fuelled cars with conventional tyres – somewhat of a surprise, perhaps.
BEVs use regenerative braking. This uses the BEV motor(s) to generate electricity from the kinetic energy in the moving BEV. The electricity is stored back in the battery.
The implication is that the BEV brake pads only need to come into contact with the braking discs during hard or emergency braking. Brake pads are thus expected to last the lifetime of the BEV.
Because of the reduced BEV brake pad wear, the particulate emissions from BEV brake pads will be very considerably less than those from conventional braking in comparable fossil fuelled vehicles.
See the “Battery theory” web page, and “Lifetime and cycles” within that, for the different types of battery which are suitable for BEVs and the individual characteristics of these battery types.
Click on the following image to obtain an interactive map of the world from Our World in Data which can be used to obtain the 2021 or 2022 grid carbon intensity of most countries.
Most grids are getting greener year by year, mostly due to the installation each year of new wind and solar farm, increasing the proportion of zero carbon electricity. New wind and solar farms reduce the carbon intensity (CO2 gm/kWh) on the grid as a whole.
There is some confusion about EV charging in a grid where gas generation does not always have to be active to provide balancing and reliability services. Some argue that it means that gas plants always provide EV charging, because gas always provides for a marginal increase in load. However, you could also argue that gas plants provide immediate power for any load which has just been switched on. Meanwhile, how do you allocate an increase (quite often now, very rapid) in wind and solar generation over time?
And as the penetration of wind and solar (plus nuclear and biomass) in a grid increases towards 100%, the argument surely falls apart. Provided there is no requirement to have fossil fuel generation active for grid stability reasons, there will be increasing times when gas (or coal) generation is no longer active at all. The UK National Grid ESO (electricity system operator) has projects finishing in 2025 to ensure the UK grid can be entirely reliable and stable with no gas or coal plants active whenever the output from wind and solar (with or without nuclear) is sufficient to meet demand.
A more logical way of looking at it, which does not fall apart towards 100% renewables grid penetration, is to assume the published average grid emissions intensity for defined periods (usually 10, 30, 60 minutes) is the result of all active loads during the period.
So the carbon intensity of the electricity used to charge a BEV should be regarded as identical to the carbon intensity of grid electricity averaged over the duration of charging. The average should take into account the charging power if it varies during a DC fast charging session.
The majority of charging for personal electric vehicles is likely to be smart charging. If most BEVs have a range of 300 miles, and an average 30 mile round trip daily commute, then there is at least a week of flexibility in when they need to be smart charged. Thus charging can be scheduled mainly when there is net surplus wind and solar power i.e. when wind and solar power available exceeds inflexible demand plus losses.
Heat pump heating systems or air conditioning systems with some insulated thermal storage (such as a tank of water or phase change material of 1 cubic metre or more) also introduce flexibility into the supply of power for heating or cooling loads. However, the flexibililty for heating or cooling is likely to be no more than a day, compared to a week or so for EV smart charging.
Thus, there is no necessity to provide smoothing of short-duration gaps in wind and solar for the proportion of demand which relates to smart charging or heating/cooling with thermal storage.
The total battery capacity in electric vehicles which are being smart charged will ultimately be much bigger than the capacity of grid batteries installed on a grid, perhaps by a factor of x6 to x8. See the “Grid storage battery” page, “2050 short duration storage” section.
For grids which already have a high penetration of wind and solar supply, more wind and solar can be installed cheaply if it is primarily to support additional BEV charging and heating/cooling loads with thermal storage. However, flexibility in when to charge BEVs, or heat homes, does not necessarily reduce the required capacity of long-duration grid backup. Long duration grid backup includes generation from green hydrogen or natural gas, and would fill gaps in wind and solar output ranging from one day up to a few weeks.
Thus, the inbuild storage in BEVs and the provision of thermal storage in some heat pump systems makes it more straightforward and cheaper to install wind and solar power to higher levels of penetration of grid supply.
With the exception of the battery, the rest of a BEV should be cheaper to manufacture than a comparable fossil fuel car.
An electric motor is simpler, lighter, cheaper and far more efficient than an internal combustion engine.
At the moment, BEVs are more expensive than comparable fossil fuel cars, due to the cost of the battery pack. Battery pack prices have been coming down steadily, but raw material costs rose in 2022 to cause a rare increase in battery prices as shown in the chart from Parkers below. The chart uses data from BNEF.
According to a 2021 Visual Capitalist article, the Wright’s Law “learnings rate” for batteries results in battery prices reducing by 28% for each doubling in overall capacity delivered.
Specifically, the colourful Venture Capitalist graphic in the linked article above was claiming that a 350 mile range BEV would be at the same sticker price as the Toyota Camry in 2023.
However, due to the rising cost of battery raw materials and other factors, it hasn’t quite happened like that. The common expectation is that sticker prices of BEVs will reach parity with those of comparable fossil fuel cars around 2025 or 2026.
Let us compare cars from Tesla, the leading BEV maker, and Toyota, the leading fossil fuel/hybrid car maker.
In the USA, with the IRA (inflation reduction act) tax concessions, as of January 2023, according to TorqueNews, the cheapest US Tesla model 3 was $44,000 before a £7,500 IRA tax discount. The minimum cost Toyota Camry started at $26,000. As of January 2023, the Tesla was still considerably more expensive, both before and after tax breaks. But Tesla prices have reduced somewhat since January, and the model 3 before the tax break is down to $42,240. It is thus moving in the right direction.
Further, the Camry costs quite a bit more to refuel, depending on which country you are in and the tax on fuel, whereas electricity in the US is cheaper. The difference between fuelling and charging costs might make a difference of $7,000 over 8 years of use, but the Tesla model 3 is still $7,000 more expensive over 8 years of overall costs.
Depreciation is currently similar for both cars, but by 2026, fossil fuel cars may be losing considerably more value as they will be known to be on the way out as old technology.
Sodium ion batteries for low end BEVs should make the difference by 2026. Sodium ion battery cells may be closer to $40/kWh by 2026, compared to an estimate for the current lowest LFP (lithium ion phosphate) battery cell prices (e.g. as paid by Tesla) of $80/kWh.
BEV manufacturing techniques are also expected to become more efficient over time, as BEVs are rather simpler to produce, apart from the battery.
Loup Venture analysts suggest Tesla will officially announce its much vaunted $25,000 “model 2” BEV in 2024, for delivery mid 2025 or 2026.
As BEV sales ramp up over time, a few particular materials are seen as key to the BEV transition, as follows:-
Currently, most BEV batteries require an average of 10kg each of lithium. For up to 100 million new BEVs per year, the total lithium requirement would be 1 million tonnes per year.
2022 lithium metal production and mining was 130,000 tonnes according to the USGS (US geological survey). To get to 1 million tonnes per year is an eightfold increase, which is a big demand from the miners. 90%+ of vehicle sales may be BEVs by 2030, and an eightfold increase in lithium extraction and processing in just 8 years is huge!
However, as of July 2023, sodium ion batteries are already in volume production by CATL, with Faradion and others also in volume production later in 2023. Sodium ion batteries will be introduced in some Chinese made BEVs later in 2023. Sodium ion batteries use only cheap and common materials, mainly eliminating battery materials supply problems. Sodium ion batteries are expected to come down to $40/kWh within a few years – half the current costs of $80/kW of LFP (lithium iron phosphate) batteries.
Sodium ion batteries in high volume low end BEV production will reduce the requirement for lithium metal. Lithium ion batteries are lighter, giving better BEV acceleration. But BEV acceleration is excellent anyway. Designers can still provide far better BEV acceleration than a fossil fuel car, even with a heavier sodium ion battery.
One possible outcome is that lithium continues to be used for high end BEVs for performance reasons. But if not enough lithium can be produced for all BEVs sold in 2030, or if lithium ion batteries remain much more expensive than sodium ion, the bottom end of the market will use sodium ion exclusively. Stationary storage is likely to use sodium ion battery cells anyway, as the extra weight is of no consequence, compared to the lower cost.
According to the Copper Development Association, BEVs require between 39 and 83 kg of copper each. Taking an average of 60 kg per BEV, for 100m new BEVs per year, the total requirement would be for 6 million tonnes of copper per year.
According to the USGS, in 2022, 22 million tonnes of copper were mined and 26 million tonnes were refined (including recycled copper). So another 6 million tonnes for EVs represents a 25% uplift.
However, BEVs are not the only green technology users of copper. Wind and solar farms and new underground or undersea transmission lines also use copper extensively. Overground transmission lines generally use aluminium and steel, but not copper. Transformers can use either copper or aluminium.
Aluminium is generally a good substitute for copper. It is slightly less conductive for a given cross sectional area, but lighter. For a given conductor ohmic resistance, a lower weight of aluminium is required, by a factor of 1.6. Aluminium is not suitable for house wiring as it requires specialist terminations to other types of wiring, and amateur DIY (do it yourself) electricians can create fire hazards by not using these correctly.
According to the USGS, annual production of aluminium was 69 million tonnes in 2022, while if all BEVs used aluminium instead of copper the BEV requirement would be around 4 million tonnes per year, so BEVs would not be a hugely significant additional demand on aluminium production. Not only can aluminium production readily be extended, but there were also 8 million tonnes of spare production capacity in 2022.
Further, Tesla has announced it will go to 48 V low voltage systems, which reduces the volume and weight of conductor required for low voltage wiring by three quarters compared with 12 V systems. Drive chains can also save conductor metals by going from 400 V to 1000 V.
One way or another, copper and aluminium combined do not appear to be an obstacle for the required eventual expansion in BEV production to produce 100% of new road vehicles with batteries each year.
Permanent magnet motors can be very efficient, but currently depend on rare earths Nd (neodymium), Dy (dysprosium) and Pr (praseodymium) to produce stable permanent magnets with high field strength, which do not lose too much magnetic field strength at their normal operating temperatures.
BEV electric motors typically use such rare earth permanent magnets. Rare earth permanent magnets are also used extensively in wind turbine generators.
In 2022, Chinese mines produced 70% of rare earths, including Nd, Dy and Pr. See the USGS reports for rare earths.
Niron has developed low volume production of nanostructured iron nitride permanent magnets to replace rare earth magnets. Nanostructured iron nitride permanent magnets nominally have a lower magnetic field strength than rare earth magnets. However, in practice, at operating temperatures of motors and generators, iron nitride loses less of its field strength as it warms up, which makes it superior to rare earth magnets. Once in volume production, iron nitride permanent magnets should enable cheaper and stronger permanent magnets, with less dependency on China for magnetic rare earths. Other rare earths have uses in areas other than permanent magnets.
Permanent magnets, which are stronger at operating temperatures, would enable motors and generators to be both physically smaller and more powerful than those using rare earth magnets. However Niron has to achieve economic volume production to make the iron nitride magnet a reality in the market.
Colin Campbell, Tesla’s VP of powertrain engineering said, at a meeting on 1 March 2023, that the forthcoming Tesla $25,000 “model 2” mass market BEV will use a permanent magnet drive motor which does not incorporate rare earths. It is not clear whether Tesla will use Niron magnets in volume production, or use either larger, or less powerful, ferrite permanent magnets.
Ferrite permanent magnets are weaker than rare earth magnets, which would make motors and generators larger. Adamas Intelligence, a research firm, is suggesting in a note that the new Tesla drive chain will include a ferrite permanent magnet motor. The note also includes more information on Niron and General Motors.
Jordan Giesige’s in depth podcast “The limiting factor” also concludes that Tesla is most likely planning to use a ferrite permanent magnet motor in the “model 2” mass market BEV, as the second phase Niron technology is unlikely to be available on the timescale required by Tesla.
Summary
Shortages of the materials above will not be a show stopper for completing a transition to 100% BEVs road vehicle sales by the early 2030s.
A lot of the other materials used in BEVs are common to fossil fuel vehicles too, and are expected to continue to be available.
A number of companies are working on self driving BEVs using AI techniques. The defined levels of self driving are given in the chart below.
So far, there are a number of level 2 self-driving systems approved in various countries or US states.
The approved level 3 systems include:-
- Honda Sensing Elite, approved in Japan March 2021 for 100 vehicles only
- Mercedes Drive Pilot, approved in Germany June 2022, Nevada January 2023, California June 2023.
2022 sales by group
The top two BEV best selling brands are straightforward and well out in front, but after that the order and sales volume start to depend on how you account for joint ventures such as SAIC. Insideevs shows it as:-
- 1,314,330 Tesla
- 913,052 BYD
- 671,725 SAIC
- 571,067 VW Group
- 383,936 Geely-Volvo
SAIC consists of a few wholly owned brands, but also joint ventures such as SAIC-Volkswagen (Volkswagen, Skoda, Audi) and SAIC-General Motors (Buick, Chevrolet, Cadillac).
Further brand groups, ordered by BEV+PHEV sales, can be found at EV Volumes, where BEV sales can be separately identified.
2021 EV sales by country
See the chart above from the ICCT Annual update on the global transition to electric vehicles: 2021 [p3 fig 2]. Note that the chart above includes both BEV and PHEV sales.
There is a clear lag of a few years in per capita US EV sales vs China and the EU/Europe.
Technology adoption follows an S shaped transition curve.
Recent technology transitions have generally taken a decade or less, while older transitions took longer.
If you fit the parameters of a typical S shaped curve to recent years of BEV sales growth (the short black line on the chart) up to the end of 2022, you get the blue “%BEV sales” curve on the chart below.
The chart above is based on this 2023 spreadsheet.\\ \\
The blue curve on the chart above implies that BEV sales will be 85% of light vehicle sales by 2030. However, the typical 16 year life time of fossil fuel vehicles means that it will be into the 2040s before fewer than 10% of light road vehicles are fossil fueled (see green line on the chart above). When addressing climate change, this lag means it is critical that the transition to 100% BEV sales completes as soon as possible.\\ \\
The implication of such a BEV sales transition is that oil demand for road transport (red line on the chart above) is likely to peak around 2025, and by 2030 would likely reduce by 6% per year straight line.\\ \\
The RMI (Rocky Mountain Institute) has now produced a September 2023 X-change report “Cars – the end of the ICE age” which adopts a similar approach to my spreadsheet above, but is much more thorough. It covers both BEV and PHEV sales, analyses the S curve calculations in the major vehicle markets, and discusses the use of different types of S curves. Its conclusion is that 2030 global plug in EVs are likely to be between 62% and 86% of light vehicle sales. It is recommended, particularly for the discussion.
Norway will ban sales of new fossil fuel vehicles from 2025. Thus, it has the most advanced BEV sales transition worldwide, with BEVs representing over 80% of new vehicle sales in Q2 2023. The Norwegian light vehicle sales figures suggest PHEV sales will be squeezed out as total EV (= BEV + PHEV) sales approach 100%.
Norway’s vehicle sales over time are in this chart in the Insideevs “Guide To Global EV Sales In 2022” article.
Note that the chart above is for BEVs only, while the BNEF forecasts below are for BEVs+PHEVs.
BNEF (Bloomberg New Energy Finance) generally has the most aggressive forecasts for green technology adoption among the commercial research and analysis firms. However, as can be seen from the chart above, BNEF has had to uplift its EV sales projections very considerably over the last seven years.
There is a good chance the BNEF process of gradually uplifting forecasts is not yet complete. In particular, you would expect EV sales penetration to approach 100% BEV sales in a reasonable period, while the BNEF 2023 forecasts for 2040 appear to approach just over 80% instead, in a much more lengthy period.
A 2019 CleanTechnica article explains why BNEF EV transition projections was even then seen as ultra conservative. Suffice it to say that a lot of analyst estimates still assume that today’s constraints will apply to the production of EV batteries in the future, which is then assumed to constrain EV production and sales.
From the Materials section above, sodium ion battery production will likely eliminate gaps in battery availability to support growing EV demand. Thus material substitutions would allow the EV market to be driven primarily by demand, and not by materials in short supply. Doubtless there will be one or two speed bumps along the way (such as automotive chips in 2022). But materials restrictions, and other supplies restrictions, are expected to occur only temporarily.
Thanks to battery price reductions and BEV production efficiency improvements, BEVs sticker prices will almost certainly be lower than those of comparable fossil fuel cars by 2026. Why would anyone then spend more money to buy a new, higher-cost, fossil fuel car instead of a new BEV?