This article is the first part of a three-part piece that will provide an in-depth analysis of the ban on the use of combustion engines.
On 12 June, Deputies adopted an amendment which had already been approved in committee on 29 May, providing for a ban on the sale of “new passenger vehicles and light commercial vehicles using fossil fuels by 2040″. In other words, sales and resales not just of 100% combustion vehicles, but also hybrids with combustion engines, will be forbidden from that date on. For the time being, heavy goods vehicles seem to be spared by the measure.
This ban seems to have been widely well received by the public, which appears to believe, as do a majority of parliamentarians, that alternative propulsion vehicles, mainly electric, will be a perfect substitute for the combustion engine in 21 years’ time and will reduce certain emissions believed to be pollutants. But is this assumption realistic?
Strengths and weaknesses of electric vehicles
On paper, the electric car is great, but…
Anyone who has had the pleasure of driving an electric car would like this to be true, but we will see that it could hardly be less so, and that legally prohibiting vehicles using internal combustion engines (abbreviated as ICE) is surely the worst way to direct the industry towards the development of cars that consume less fossil fuels.
On paper, the electric vehicle (EV) is attractive: the engine produces no emissions in situ, it is silent, its constant torque makes it a pleasure to drive, the engine is vastly more simple mechanically than today’s combustion “gas factories”, and it will be easier to maintain as soon as enough mechanics are trained up. Everyone who has tried an electric vehicle sings the praises of the driving experience.
In addition, the engine efficiency of an electric motor/transmission unit is between 60 and 75%, while a combustion motor/transmission unit has an overall efficiency of between 15 and 20%. To put this into another numerical context, this means that to move the same weight over the same distance at the same speed, takes 3 to 4 times more energy for an ICE than an EV. That becomes very attractive if we confine ourselves to looking at a superficial analysis of the two modes of propulsion.
But the reality is much more subtle. From the point of view both of the vehicle itself and of the energy production and distribution system, the disadvantages of electricity outweigh its advantages, and the foreseeable rate of improvement of these technologies does not make it possible to be certain that all these shortcomings will have vanished by 2040.
The Achilles’ heel of electric propulsion: the battery!
If the powertrain of an EV is unbeatable compared to a combustion engine, the EV has one huge weakness: its power storage!
The “energy density” of current fuels is about 45 Megajoules (or 12.5 kWh) per kg. In comparison, the best current Lithium/ion batteries (the best technology available today) have an energy density of 0.5 to 0.6 MJ/kg (figures for the Renault Zoe and the most expensive version of the Tesla S respectively). This means that one kilogram of battery is capable of delivering 75 to 100 times less energy than one kilogram of fuel. If we look at volume rather than weight (both criteria are important in car design), the ratio is slightly less unfavourable to electricity, in the range of 1 to 40.
Even taking into account the 3 to 4 times greater efficiency of the electric powertrain, a fossil fuel tank can deliver 20 to 25 times more energy to the wheel of a car than the same weight of a properly charged battery. This is why a Tesla, champion of the electric vehicle range, has to carry over 600 kg of batteries to enable a real range of 400 km (real range and advertising range are two different things…), and weighs in at over 2.6 tons.
The battery, a not-so-simple component!
But the battery issues do not end with their total energy capacity. First of all, not all the electricity from the battery is used to run the electric motor. As in any car, power is also necessary for the heating, air con, and so on. The EV is not at a disadvantage here compared to the ICE, but with equal usage time, given the issue of low storage capacity, these functions are more detrimental to the autonomy of an EV than an ICE.
Current battery systems are complex. This diagram shows how to switch from an individual component to a battery system:
For a battery to work properly, all the components have to work together, the cells have to be drained at more or less the same speeds, it has to be able to sense its charge level, etc. The management of this balance is so complex that a battery needs an onboard “Battery Management System” or BMS, which ensures that all battery cells discharge or recharge at approximately the same rate, that the batteries do not overheat, etc. This BMS adds further weight to the battery, reducing its mass density. It consumes some of the stored electricity on itself, although the performance of the best BMSs has apparently made great progress in recent years.
BMSs are put to the test time after time. As a result, the battery’s discharge-recharge cycles reduce its capacity over time. Tesla estimates that the capacity of its battery systems will be reduced by 30% after 5 years, despite the care taken by the BMS to “even out” the charging cycles, reliant in particular on the quality of the charging stations. Worse still, a “conscious” driving style increases this tendency of batteries to wear out prematurely.
Equally annoying, the frequent use of “fast” charging (which is still much longer than filling a petrol tank) also degrades the battery capacity over time! In other words, “refuelling in a few minutes” with an EV is a long way off, and this, alongside price, is the main obstacle to consumer acceptance of the EV.
Another concern: all drivers have noticed that in cold weather, their vehicle’s range decreases: not only does the vehicle have to be heated, but in addition the chemical reactions that are the source for the battery’s energy are diminished. Another handicap, the EV is about 50% heavier than its combustion equivalent of the same volume, which slightly reduces its advantage in terms of efficiency.
In short, the reduction in performance of the electric motor-battery combination is much greater over time than in the case of the internal combustion engine, which certainly loses a little in efficiency as it ages, even if it is well maintained, but whose energy reservoir demonstrates constant performance!
The battery: huge direct and indirect costs!
The use of rare materials in batteries and high-performance electric motors is regularly highlighted by the media. The journalist Guillaume Pitron has written a well-documented book (link) on the subject, showing that mining these minerals causes major ecological and social disasters… But very localised and a long way away from us…
The scarcity of these materials has another particularly problematic effect: batteries are very expensive. A battery pack with full BMS now costs more than 200 Euros per Kwh (It is difficult to find reliable figures, because some pro-EV publications mention lower costs but only include the cost of actual cells, which is an economic calculation unworthy of the name). Despite a continuous decrease in this price in recent years, a 40 kWh battery (such as the Zoe) still costs more than 8,000 Euros, which explains the very high purchase price of this vehicle, and the fact that all states that want to promote electric vehicles have to subsidise it heavily. And despite this state aid, the market share of electric vehicles remains negligible, at around 1.5% in France.
The electric vehicle is not the only problem. So is the network and production!
The situation is no better on the electricity production and distribution side. In countries where nuclear does not play a large part in energy generation i.e. almost everywhere, the increase in the efficiency of the electric powertrain is offset by the relatively low efficiency of thermal power plants, i.e. about 40% for a modern and well-maintained plant. This figure is likely to be significantly lower in a country where energy producers do not have the capacity to invest in the latest technologies.
As a result, fuel that is not burned by the ICE is burned upstream at the plant. If the costs of producing and distributing electricity and fuels are included in the efficiency equation of the propulsion chain, the advantage of the Electric Vehicle decreases. The American Physical Society indicates that in terms of primary energy use for driving (not including its manufacture), the EV is 1.6 times more efficient than the ICE, which is decent, if not as exciting.
Will we have enough power plants?
And what about the amount of electricity needed to power all these EVs? If tomorrow, all ICEs were replaced by EVs in one fell swoop, to achieve the same transport requirements (13,000 km/year per vehicle plus road freight transport), a rough calculation shows that electricity production would have to be increased by about 30%, or something of the order of 160 additional Twh.
Currently, France consumes 50 Million M3 of road fuels annually, or 50 billion litres, or about 490 TWh to move passengers and freight. Taking into account the best engine efficiency of the electrical system by a factor of 3, 160 TWh of EV power requirements would be required if the entire fleet was replaced. France produced 550 TWh of electricity in 2018, so this production would have to be increased to 710 TWh, all other things being equal.
Of course, in 2040, there will still be many ICEs left in service, so the need for additional electrical TWh will not be as high. On the other hand, travel demand is likely to increase, simply because of population growth. In any case, a significant increase in electricity production will be necessary.
However, our governments do not want to INCREASE but DECREASE our energy production and are talking about not renewing our nuclear fleet, and in any event plan to reduce its share of our energy mix to 50%, leaving 30% of production to intermittent renewable energies! And of course, if we need electricity at night, we had better not rely on solar energy to provide it.
As for wind power, well… in the event of lack of wind, which is not such a rare occurrence at night either, it will require power plants (fossil, since nuclear power will be reduced!) to provide back-up… Or batteries! But the inadequacies of these technologies, already glaring as regards vehicle propulsion, would be even more so if required to store the gigawatt hours of production from windy periods and return them to the grid in good condition in periods of low winds. The technological stalemate is stark.
There is therefore a contradiction, or even an inconsistency, between several decisions recently enshrined, or in the process of being enshrined, in French law. Under these conditions, it is not clear how the power needed to supply an EV fleet will miraculously be secured by 2040.