For over a century of hegemony of fossil fuels in the car: mainly petrol and diesel. However the automobile sector moves voluntarily, driven by the market (oil prices and consequently fuel) itself, or forced by government legislation (limits lower consumption and pollutant emissions), to new forms of energy that drive the cars of the future.
So timidly have developed other alternative fuels such as liquefied petroleum gas or natural gas, also fossil fuels, or bio-fuels, which are usually a mixture in different proportions of renewable fuel of vegetable origin and fuel petrochemicals. Currently electricity is running on multiple automakers as the alternative future with plug -in hybrid cars, electric cars, and electric cars hydrogen fuel cell.
In both cases we have an electric motor to drive the wheels
A couple of years ago and we put facing the electric car and plug-in hybrid car. It’s also a couple of years reviewed in two extensive articles situation of hydrogen car, especially electric car hydrogen fuel cell, first explaining its technology, after explaining its challenges.
Now we would like to facing the electric car and the electric car of fuel cell hydrogen, also using the occasion to briefly review the developments and advances that have occurred in both technologies at this time.
To begin, we should remember briefly and simply what we are talking about:
- An electric car, also sometimes called car “electric only” car “100% electric” or electric car battery is a car in which the wheels turn driven by a electric motor which gets the necessary energy accumulator which stores, usually a battery, but could also be a capacitor, and can be recharged again and again connecting the vehicle to a socket, conventional or specific current, or by inductive charging.
- An electric car of fuel cell hydrogen, which stands for Fuel Cell Electric Vehicle is a car in which the wheels turn also driven by an electric motor that gets the necessary energy from a not very large accumulator that stores (usually also a battery), and a fuel cell powered by hydrogen, which when combined with oxygen taken from the air, generates electricity on board the car is transferred to the motor or battery, as appropriate. In principle this type of car is not plug, although technologically possible and there are variants that are themselves (at least as a prototype).
We could also understand the electric car of fuel cell hydrogen as a series hybrid car, or as an electric car extended range, in which the extension system autonomy beyond what accumulates a battery, is a fuel cell that generates electricity during operation of the car, and complete accumulated in the battery to have more autonomy.
Although there are different fuel cells, for example ethanol or methanol, which now prevails in the automotive industry appears to be the hydrogen.
Advantages of electric cars
An electric car is cheaper than an electric car of fuel cell hydrogen. An electric car average, without any aid or subsidies, such as the Nissan LEAF, currently the most sold worldwide, battery property and the cheapest version (this is the official price “rate” including taxes, discounts or have not included aid for the purchase, although would have, and the price would be reduced).
Both locally and globally, the electric car is more efficient than a fuel cell car and a car with internal combustion engine. This is because energy consumption certified to travel 100 km is less in an electric car.
If we consider the overall consumption, which in a car combustion would talk about consumption “well to wheel”, i.e. understand that the total energy expended in reality a car is greater than strictly being spent running the car, for the electric car, we considering losses in generation, transmission, distribution, and battery recharge, we’re about 30 kWh / 100 km. To give us an idea, a car gasoline average is around 60 kWh / 100 km.
Lower overall emissions
Operating or electric car, or the car of fuel cell hydrogen emissions generated locally, i.e. do not pollute the air where circulating. But globally, that is, considering the generation of electricity, or hydrogen production, do generate emissions. Emissions are lower in the electric car because it consumes less energy. Let’s explain.
It is true that the emissions depend on the type of power source that has been used to generate electricity, as each has its corresponding emission factor.Generating electricity from coal is nonsense ecological level as causing the electric car generates more emissions even a car with internal combustion engine, and instead if the electricity is generated by renewable sources are significantly lower emissions.
Taking as a basis for comparison the same energy source to generate electricity with which the battery is recharged, or with which the renewable hydrogen produced by electrolysis of water is used, and thus having the same emission factor, the less energy consumed in the electric car means lower emissions.
When talking of global emissions of an electric car, several manufacturers have made in certification bodies and certification, such as the German TÜV, life-cycle assessment of their respective models, where not only is considered consumption car energy and emissions during use, but also for the generation of electricity, even by manufacturing and recycling vehicle end.
Serve as an example the life-cycle assessment of the Renault Fluence ZE, the BMW i3, the Volkswagen e-Golf or Kia Soul EV. In all cases the conclusion is that, the electric car produces fewer emissions than a car equivalent gasoline or diesel. An electric car of fuel cell hydrogen, for now I have not seen any life-cycle assessment (but do not say it does not exist, eye).
Lower cost per km
We have calculated in other items from the cost per kWh of electricity bill, adding of course taxes. Compared to a car with gasoline or diesel, and compared to an electric car hydrogen fuel cell, the cost per kilometer due to energy consumption is lower in the 100% electric car.
As the price of electricity varies, is not the same recharge during the day with one-time fee to recharge overnight with rate of hourly discrimination, each car has a consumption depends on driving style, the efficiency of recharging can also vary according to the circumstances, and each power company may have a slightly different price, we must talk about a range of approximate prices.
It is easier to build electric cars with a lot of power, which in the case of electric cars fuel cell. Serve as shown in the Tesla Model S, the most powerful version has 539 hp (this figure is lower than the 772 hp that would result from adding the power of the front engine and rear, as is limited by the voltage and battery capacity).
Not talk about any prototype or exclusive car that few units are manufactured annually on request, but a car that is manufactured in series and flowing through the streets. In a fuel cell car hydrogen, as we shall see a little later, manufacturers are moving in quite minor powers.
It is easier to have the necessary infrastructure
Although the infrastructure of charging points in areas of public use has been growing slowly, if we look at quality as it is operational. However, while this is so, to use an electric car is enough to have on hand a conventional outlet of schuko and 16A where to plug the car.
If you have no garage certainly, the matter is more complicated. Today it would be impossible to move to a hydrogen car because it would where refueling.
Disadvantages of electric car
Overall autonomy is less
With few exceptions such as the Tesla Model S battery of 90 kWh, which standardizes 557 km, but you also, have to pay, autonomy currently approved in electric cars average trying to have a relatively affordable price moves generally between 160 and 300 km.
This autonomy is less than that of a conventional car of the internal combustion engine, and less than the autonomy of electric cars homological fuel cell hydrogen. The new BMW i3 and Volkswagen e-Golf will arrive after summer have seen their autonomy to 300 km, and in one or two years come new models with autonomy over 400 km, among others as the Chevrolet Bolt or Tesla Model 3 (when a fact include it, for now we are left with these figures).
You need more time to recharge
If we recharge at home, depending on the capacity of the battery electric car, installation and power recharge fully recharge an electric car can take between 4 and 12 hours. If we think that the car can be recharged overnight while parked, it does not seem such a serious problem.
Away from home in points fast charging or super-fast, a recharge may require 30 to 60 minutes. Although less time, still more than what it takes to respostar at a gas station or a hydrogenation. For now there are no more options, as the quick -change system battery that seemed so interesting and promising to “recharge” in just a minute and a half and continue the journey, in practice does not exist.
Some, like Better Place, were ruined because there were very few models compatible electric cars with battery changing system, and very few customers who will use the service and allowed to make the business model profitable. Others, like Tesla Motors, because they say there is not enough demand among its customers, and now have a single station quick – change battery, and it is still in a pilot phase and does not work as fast as promised.
Drivers need to change their habits
For some drivers, a car is less than the 800 to 1000 km of autonomy that some current diesel is too big a change. Planning travel and stops to recharge or battery dosing and drive more efficiently not convince others. For many having to wait hours to recharge the car is a drawback that they are unwilling to accept. The habit of refueling almost anywhere in 5 minutes in a service station is entrenched. All this slows down a lot when buying an electric car.
Extreme temperatures affect more to autonomy
With very low temperatures, the range of an electric car is considerably reduced-due to the heating of the cabin, but also to self – heating of the car battery to have a proper operating temperature.
Very high temperatures can also affect performance in some models, not only because the air conditioning in the passenger compartment is an important consumption, but because the cooling system battery also consumes battery power itself, although usually noticed its effect unless with the cold.
With a low state of charge of the battery power is reduced
Although not as common, and many drivers do not reach this situation, do not overlook that despite the theoretical maximum power of the car, when the state of charge of the battery is very low, the power that can give the engine is reduced.
The useful life of the battery limits the car
In recent years they have been making advances in the chemistry of lithium ions, the most commonly used today in electric cars, resulting in greater wear resistance effect of cycles of loading and unloading and by heat. Yet there is no doubt that right now the limiting of the life of an electric car is the battery factor, which after some time will need to change. Manufacturers already planned, such as Nissan, and depending on which cases must take into account its cost in vehicle maintenance.
You may also like to read another article on Blog-Collector: i NEXT, the first electric autonomous BMW car, will arrive in 2021
Advantages of electric car hydrogen fuel cell
In general the advantages and disadvantages of electric car hydrogen fuel cells are usually reverse the electric car, although in some respects tend to equal those of each other gradually.
Overall autonomy is greater
Autonomy approved in an electric car hydrogen fuel cell is situated between 500 and 650 km, much like a conventional gasoline car. Not to be confused between the different approval cycles, more or less optimistic or more or less realistic, they are yielding different autonomous. For example the new Honda Clarity Fuel Cell, which replaces the old FCX Clarity, homologated in Japan to 750 km of autonomy, but in the US accredits 502 km.
The Hyundai ix35 FCEV 594 km homologated and Toyota Mirai 650 km. The particularity of the autonomy of cars hydrogen fuel cell is that its autonomy depends on the amount of hydrogen that has been introduced in the tanks, and this depends on the pressure that can be compressed.
The maximum range is obtained with accumulated 700 bar hydrogen pressure, about 690 times atmospheric pressure. If hydrogen is introduced under pressure, to 350 bar, autonomy is to be halved, and we were about 250 to 325 km. Not all hydrogen refueling stations can compress 700 bars, so must be taken into consideration.
It can be refueled in under 5 minutes
In addition to autonomy, certainly the great advantage of hydrogen cars is that you can fill up very fast with a jet of hydrogen in a time of 3 to 5 minutes, without involve a demand for electric power installed very high, as would happen in the case of superchargers, and unworn faster than desired service life of the battery.
Drivers do not have to change their habits
While this may seem a banality, because the human being is a creature of habit, in the end it turns out that is more important. Many drivers do not want to change what they have been doing all your life, do not want to have to wait to have its heavy car, or do not want to have to plan a trip with an intermediate stop where there is enough time to recharge the battery.
Sometimes they cannot because they do not have a parking space where to plug in an electric car, and the only option that they are used is to go to refuel at a service station. The idea of not having to change the current way of using and refueling cars, seduces many drivers for these cars.
Extreme temperatures do not affect both the autonomy
I commented on one occasion an engineer from Hyundai that an advantage of electric car of fuel cell hydrogen is that unlike what we were saying before the electric car 100%, no matter how extreme they are the temperatures barely notice changes in performance of the car, nor is there a significant change in their autonomy.
Disadvantages electric car hydrogen fuel cell
Higher purchase price
We saw above what the price of an average electric car. Today an electric car of fuel cell hydrogen is very expensive, and far more expensive than an electric car, though manufacturers strive to lower its price and promise that in the future will be more affordable. The fuel cell above all, rare and precious metals, and hydrogen tanks to withstand very high pressure, they are the main culprits of their high manufacturing cost.
The average consumption of a car Hyundai ix35 FCEV as is 31.3 kWh / 100 km.But considering that you have to produce the hydrogen, compress it and transport it to a refueling station, the total energy consumed globally is greater, resulting in the order of 55 to 60 kWh per 100 km in a favorable case, but even more in worst cases, according to generate hydrogen. Manufacturers now do not usually give any figures, but for example in Hyundai itself recognized, without going into details, that the hydrogen car is less efficient than the electric car, and Toyota say that the efficiency of the Toyota Mirai is the order of 50%, while an electric car is around 70% (not without much detail).
Higher global emissions
As explained above, requiring more energy both locally and globally for 100 km, it is also generated more emissions (is directly proportional to the emission factor of power source has been considered). We must understand that hydrogen is not an energy source but an energy vector, carrier or carrier (in English). That is, to have hydrogen to refuel a car fuel cell must be produced, and in the process more energy than it then contains and we will return the hydrogen obtained, since in the process there are losses consumed.
If one considers that currently about 95% of hydrogen is produced in hidrogeneras plants from fossil fuels, natural gas mainly, cannot be considered that hydrogen is renewable, even not the vehicle is zero local emissions.
Cost per km more
Perform 100 km with an electric car of fuel cell hydrogen is considerable more expensive than an electric car, and depending on what cases even more expensive than a car with gasoline or diesel. Produce hydrogen is currently not cheap because it has to pay the cost of raw materials and energy consumed. If produced by electrolysis of water, so that it is renewable, it is even twice as expensive as by reforming natural gas. That is why they are researching and developing new methods of hydrogen production, cheaper, or renewable, or both at once.
Cars with less power
The Toyota Mirai has a power of 154 hp, the Hyundai ix35 FCEV has 136 hp, and the new Honda FCX Clarity has 140 hp. The limitation is the hydrogen fuel cell, because the more powerful, bigger and face it. Also the propulsion battery is small and does not have much buffer or reserve power limits the maximum power.
One option, if you do not want to opt for a larger stack, is to opt for a larger battery that would meet the instantaneous demands of specific peak power, but then we would be taking up even more space in the car, adding more weight and further increasing the cost , so the current manufacturers follow all basically the same line and electric car concept fuel cell hydrogen.
It is difficult to have small cars
Due to the technical complexity of an electric car fuel cell, all components must include the vehicle (motor, control unit and converter, transmission, battery, fuel cell and hydrogen tanks), and in particular the volume occupied by hydrogen tanks for the moment throwing cars manufacturers are usually quite large. The Honda Clarity Fuel Cell measures 4.92 m long, 4.89 m measured Toyota Mirai, and a model not as large as the Hyundai ix35 FCEV measures 4.41 m. So far no smaller models, such as compact or utility, thus being reduced supply.
The trunk is usually smaller
Although it may be a contradiction, and although generally these cars are great as just explained, precisely because of the same reason, the space occupied by all components, especially hydrogen tanks, the trunk of these cars is often less than the similar electric cars. For example, the Toyota Mirai, despite its 4.89 m long, has a load capacity of 361 liters. For reference, consider a Nissan LEAF 4.44 m long is 370 l and a Tesla Model S 4.97 m long, has two baggage handlers and a total volume of 895 l.
Complex and costly infrastructure poor
If sufficient electric car with a relatively small investment to have a charging point and make do with work, things change a lot with the hydrogen car.
In some cases as in California, where the situation is more favorable, it is not so easy to find where to refuel. There are already marketing the Toyota Mirai and other hydrogen cars, and given the case that Toyota had to stop deliveries of the car, and even send tankers with hydrogen to dealers for customers to refuel.
For the truly useful infrastructure, it is also necessary that the docking station allows refueling at 700 bar, to enjoy more autonomy, and that hydrogen is of high purity, or the car may not work.
The investment required to install a hidrogenera is quite high, although this is relative and depends on how you can capitalize with use.
The reality of other countries like Japan is that hidrogeneras out a little more expensive. With this type of costs, it seems difficult that a business wants to invest in building a hidrogenera, with no guarantee that the investment will recover, or without subsidies.
Hydrogen is highly volatile and flammable
Although manufacturers design and build storage tanks of hydrogen to be very tough, and different security systems are included to detect hydrogen leakage for certain drivers may weigh against the electric car of fuel cell hydrogen, the hydrogen is highly flammable.
The life of hydrogen tanks and battery limits the car
The life of hydrogen tanks, at least one safety and regulatory question, is limited to 15 years. Do not forget that 700 bar pressure is a lot of pressure. The lifespan of the fuel cell has been improving gradually, and is not as limiting as before, but still is. For example brands such as Hyundai we explained that the fuel cell is estimated that its power is reduced by 15% after about 225,000 km of use.