Hydrogen against electric, who is more efficient?

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Honda FCX Clarity

for years manufacturers have abandoned the use of the hydrogen as an alternative fuel for the internal combustion engines of conventional -primarily designed for use in gasoline – and prototypes that are coming out not opt for that solution. BMW and Mazda, for example, had prototypes that worked as well.

But no, the future of the hydrogen does not pass for use in engines of internal combustion, since the efficiency of the process is limited by the Cycle of Carnot, and it is a waste of energy. It leaves more to account that the internal combustion engines using synthetic fuels or gas.

The best use that can give the hydrogen is to wrap it in fuel cell. These devices mix the hydrogen stored in pressure tanks with the oxygen present in the air, giving rise to two products: electricity and water vapor. Therefore, they are cars zero emission, as the electric.

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Volkswagen Golf HyMotion Concept

In fact, electric cars and fuel cell hydrogen are extremely similar, because in both cases they use electric motors to the movement of the car. The most important difference between one and the other is from where does the electricity to feed the engines.

  • car Into a hydrogen fuel cell, the energy is generated on board, by mixing hydrogen and oxygen
  • In an electric car, the energy has been obtained from external shape, and the chemical reaction of the elements of the batteries give rise to electricity

The stack of fuel have to refuel, and the batteries have to recharge.

The main advantage of hydrogen is that it allows a stopping time very short to recover energy, while the electric needs more time. Now, the electric is gaining in a very important aspect: the total amount of energy used is smaller, so that makes more sense from the economic point of view.

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performance Difference between fuel cells and batteries electrochemical – Credits: Phys org // Ulf Bossel

In the graph, we can see the difference. We start with 100 kWh of energy obtained from renewable way, that is to say, without generating polluting emissions or carbon dioxide (CO2). Of those 100 kWh we are going to see how much energy we can put at the service of electrical motors, and convert it into useful motion.

The electric car has a high efficiency once the energy is already on board, but did not reach there by science infused. You lose 10% of the energy through the electrical network, and the process load has a loss of approximately 15%. Both losses result in 69 kWh useful for engines.

In contrast, the fuel cell stack also has a few losses, especially when you convert fresh water into hydrogen using hydrolysis. In the second place, the large loss occurs when you convert the hydrogen resulting in a product transportable, easily and securely, either by compression or liquefaction. In the best case, will be 23 kWh useful to move the car. According to this chart, the process is the triple of efficient electric.

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Mercedes-Benz B-Cell prototype fuel cell stack of Daimler

By that of contrast, another author’s figure in a 30% performance gain for the electric, not a 300%. In any case, using a fuel cell is a process less efficient and wastes more energy. Therefore, if we are thinking in the best performance, and less energy expenditure overall, there is to bet more for the electrical than for the fuel cells.

Both the batteries as the fuel cells suffer from a degradation of their components and have a limited useful life

In two previous articles, we saw the advantages and the disadvantages of using hydrogen. And gives that to think that three manufacturers were putting strongly for the fuel cells -Toyota, Hyundai and Honda – have announced in recent weeks a intensification of their mobility programs electric.

Part of the work is already done, to go from fuel cell to batteries means changing a few components, but the rest are still common. To this day, the fuel cell stack is very expensive, and the fuel is also a, while the electric ones are a technology already on the street, and within the reach of many pockets. Hydrogen can not say the same thing, starting with the commercial offer.

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In my opinion, you are not going to impose a model in front of the other. The electric ones are the most suitable for short and medium distance, but the hydrogen will continue to be the best idea for the long haul. Surely the weight of the electric will be higher than that of the fuel cell stack, at least while the latter are not competitive in costs.

Toyota will continue betting on the hydrogen fuel cell the Mirai and the future Lexus of hydrogen, but intensifies its efforts on plug-in hybrids. For its part, Hyundai brings this year to market the IONIQ (hybrid, plug-in hybrid and pure electric) and will have a SUV full electric in a few years. Honda will not stop focusing our efforts on the FCX Clarity, but the same car will also have version 100% electric.

Other manufacturers working on fuel cells include General Motors, or Daimler, are also developing programs of electric motors, and will be put on the market more models in a short time. None of the manufacturers mentioned waiver of the fuel cell, but those who bet only for this technology tend to be zero. Those who bet on several horses winners will have more opportunities in the future.