Thank you Artur for your illustrative answer that mentions at least two positive points of hydrogen based vehicles.

The answer of this question depends on many factors. Let me start by saying that the driving unit in Battery Electric vehicle is battery while driving unit in hydrogen electric vehicle is a Fuel Cell. (Its important to mention the driving unit because the infrastructure of battery electric vehicle and Hydrogen electric vehicle are different which makes a lot of difference). If you want to compare the efficiencies of batteries with fuel cells, there is no way you can compete with batteries (FUEL CELL 50% and Batteries 95%). When it comes to economics, fuel cell is cheaper than current batteries, but if you consider the fuel, hydrogen is costly compare to the fuel of batteries (Electricity). This is an opinion of a researcher but if you want to know what big companies are thinking. Read the excerpts of a survey below

KPMG surveyed almost 1,000 senior executives from “the world’s leading automotive companies” and found that 62% of them believe battery-powered electric vehicles (BEVs) will fail due to infrastructure problems.

An even stronger majority, 78% of them, believe that fuel cells hydrogen is the future of “zero tailpipe emission” driving. In my opinion, the reasons are political.

I read an article about this subject. It says that electrical cars are more efficient

Please check the link below

https://tonyseba.com/toyota-vs-tesla-can-hydrogen-fuel-cell-vehicles-compete-with-electric-vehicles/

Good luck in your research

Thank you Umair for your excellent answer which assesses the batteries in comparison with fuel cells for powering electric vehicles. Please note that my question is about the comparison of electric vehicles as compared with vehicles that use hydrogen fuels for supplying internal combustion engines i.e. burning compressed hydrogen not using it to produce electricity via fuel cells. By the way, I read a recent industrial report which claims that the efficiency of some fuel cells >70%

Thank you Ehab for sharing the report which compares batteries and fuel cells for powering electric vehicles. It seems that the my question in not sufficiently clear because you and Umair thought that the hydrogen vehicles refer to fuel cell powered vehicles. I am asking about electric vehicles in comparison with internal combustion engines powered with hydrogen for thermal energy production.

The following report is relevant to my question. In addition, modifications of the pure hydrogen for producing hydrogen based fuels have been published by many authors.

https://www.forbes.com/sites/quora/2017/06/27/why-are-car-manufacturers-ignoring-hydrogen-engines/#4e402d8e4027

Hydrogen is very hard to store and transport. Electricity is relatively simple to do both. H2 has very low energy density (J/m3 in the tank), but can be stored as a metal hydride for a higher density but much higher mass.

The article compares a 20 gallon fuel tank to a 1/3 m3 hydrogen tank at 250 bar. Lets assume that is a glass lined steel tank - the glass may keep the steel from becoming embrittled by the H2. The 87 gallon hydrogen tank at that pressure would mass about 100 kg of high strength steel (plus whatever protection it needs against crashes). And it would hold about 7 kg of H2. The 20 kg gas tank would mass about 8 kg, and hold about 65 kg of fuel. So, same order of magnitude of overall mass, but takes up 4x as much space. And is a much more expensive tank.

No, stay with liquid fuels - much higher energy density, once the container is considered.

Thank you Douglas for your answer. You said 'Hydrogen is very hard to store and transport', please explain. Didn't we already have nature gas technologies for storage, and transport of natural gas? Is not possible for similar technologies to be used for the hydrogen? Could you also please consider to compare the hydrogen with batteries rather than natural fossil fuels?

Hydrogen gas is highly reactive and highly mobile. It will pass through (and potentially react to) plastics, dissolve in metals and cause embrittlement - pipe goes bang. It exists, for all intents and purposes, only in a gaseous phase, so you can't transport a liquefied version (like natural gas or propane). About the only way you can contain it safely is some kind of glass-lined steel pipe. A dent in the pipe would mean throwing it away and starting over - that's expensive for a gas tank.

I see there are carbon fibre tanks designed to contain very high pressure hydrogen that cost in the order of $20/kWh stored, and have an energy density of about 0.8 kWh/kg, when operating at 70 MPa.

Lets compare that to lithium batteries. In the order of 0.15 kWh/kg, and maybe $330/kWh stored.

Surprising to me, that means the containing H2 is significantly cheaper than the storage of electricity. I guess that's why they have Ballard Fuel Cells.

But what does it cost to compress to 70 MPa? How about just to 25 MPa (250 bar)? What do you do with the waste heat from compression? When it is being used, do you use the expansion of the gas to provide air conditioning? How is the H2 generated? What would the system efficiency be? Inquiring minds want to know!

Say we start with water, split out H2, compress it to 25 MPa in a multi-stage compressor. Lets assume we start at atmospheric, and the water splits at 75% efficiency (the rest goes off as evaporation). PV^(7/5) is a constant for a uniform mix of a diatomic gas, and I'll use a cubic meter for easy math. 100 kPa * 1m3^(7/5) = 100 kNm^1.4. I compress to 25000kPa and it becomes 19 litres, and the temperature becomes 1450 K. You have to dump 1.5 MJ as heat, while the hydrogen stored will contain about 11.6 MJ. Assuming the compressor is about 50% overall efficiency (I think that's high, but OK), Then we start with 29.7 MJ going into the electrolysis, with 11.6 MJ chemical energy available. We'll say 60% efficiency for the fuel cell, for a total output of about 7 MJ electricity. That's 39% system efficiency.

Start with 29.7 MJ of electricity in, to get 19.3 MJ of energy in the tank, with a final output of 11.6 MJ, plus costing for the solar panels ($13000)compressor ($1000), fuel cell ($500), and tank ($120). For 7 MJ per day of portable power. Something well over $2000 per MJ/d.

Compare to 7.7 MJ of electricity into the batteries, requiring solar panels ($3500), and batteries ($5000). For 7 MJ per day of portable power. $1200 per MJ/d.

Well, that was fun. In the end, I still think the extra complexity of a hydrogen economy is not worth the cost.

Thank you for valuable analysis, but the fair economic comparison between the systems you mentioned should consider some other issues, such as:

1. Lifetime of components. For example, in 25 years, the batteries are expected to be replaced about 8 times. In addition, I am not sure that there is a preventive maintenance strategy that can contribute in increasing the lifetime of the batteries.

2. It is known that the costs highly dependent on the industry volume. Therefore, all the mentioned costs may be highly reduced if the hydrogen system are widely adopted and utilized.

3. The bulk energy storage using hydrogen is much more technically feasible in comparison with batteries. In addition, in power grid applications, transmission of the bulk energy stored in an electrical form will cause energy waste and additional costs that may be reduced by using the hydrogen as an energy carrier then utilizing it as desired as close as possible to the load location. This is provided that the hydrogen is produced through electrochemical process via electrolyzers or thermal process via, for example, nuclear energy.

IC engines regardless of fuel source are horrible in efficiency most hydrogen engines run in a modified gasoline engine typically are 20-25 % efficient and in a research engine run very differently by Sandia they got to about 40% efficiency - aboutt he same as diesel. Electric battery cars are about 90 % efficient. Hydrogen leaks more easily than even gasoline as well. Batteries now last 10 years so component life is not much different. Hydrogen fuel cells are 40-60% efficient (due to the large parasitic pumping of gases) but they are still expensive even compared to a battery. If current projections come to pass by 2022 we will have electric cars with 500 mile range so it is likely as long as the batteries get better that electrics will win out (and this does not appear insurmountable particularly with solid state batteries). In addition everyone has electricity at home to feed their car with - there are only a handful of hydrogen fuel stations out there today.