Why Hydrogen Isn't Feasible at Fueling Our Cars

I thought it might be good to start with a little physics.

Assuming an automobile weighing 1,000 Kg has to drive up an 1 meter (3 feet) high incline, doing this within 10 seconds.

The energy required to do this task is: 1,000 kg x 1 m / 10 seconds = 100 kg-m/s or 1.33 horsepower. It also translates into 3,600 watt/s or 3.6 kWh. It makes no difference what type of fuel powers the car, as long as the 3.6 kWh amount of energy is provided for. From an economic point of view, all we want to know: What is the cost of available fuel to provide these 3.6 kWh?

Hydrogen (H2) looks like an attractive alternative to gasoline or oil from an environmentally point of view. The problem is, it is very costly to produce.

Electrolysis currently is the only commercially available method. To produce 1 kilo of hydrogen one needs an input of 39 kWh of electricity. This one kilo of H2 has the energy equivalence of 22 kWh.

At current electricity prices of 14 cents per kWh, the 22 kWh costs $5.46 or, 25 cents per kilowatt. But first, we have to convert H2 gas into electric energy in order to drive our electric cars. This involves gas fired power plants (42%), the grid (90%), transformers (85%).

This leaves a total overall efficiency of (30%), ccording to a study I published in my blog of 12/4/2019. This overall efficiency leaves only 22 x 0.3 = 6.6 kWh for the power plant to sell you. The true cost of the power plant producing electricity now is 22/6.6 kWh times $0.25 = $0.83 per kWh going to your meter.

Yet, the power company is only allowed to charge you an average of $0.14 per kWh. As one can see this is not a profitable business and without government subsidies, it will never be practiced.

In comparison, a gallon of oil has the energy equivalence of 40 kWh. At current prices of $1.19 per gallon (at $50 per barrel), one kWh will cost about 3 cents. Here, too, we have to include the cost of producing electric power from oil. Here, the efficiency too is about 30% as above. This gives the power plant an overall cost of $0.03 / 0.3 = $ 0.10 per kWh, at an reasonable profit margin.

Let’s assume a truck has a converted engine and can burn hydrogen directly without converting the gas into electricity as in the above example.

Let’s start with 1 Kg of H2 or 22 kWh of energy. Transportation of the gas might cost 10% leaving about 20 kWh equivalency. Assuming further, that the truck engine runs at 35% efficiency, which leaves the energy turning the wheels at 7 kWh.

Remember from above, the cost of producing 1 kWh of H2 was $0.25. this then makes the cost of 7 kWh = $ 1.75. This compares to using diesel oil at $3.00 per gallon where one gallon has 40 kWh energy equivalence. Using again 35% energy efficiency which leaves 40 x 0.35 = 14 net kWh per gallon or, $3.00 cost / 14 kWh = $ 0.21 per kWh at the wheel. It is obvious why truckers try to stay with Diesel oil.

The conclusion from all this is that one has to wait for a wide range use of H2 until a lower cost of production is available.

Dr. Hans Baumann, a former Corporate Vice President and founder of his company, is a well known inventor, economist, and author having published books on scientific, economic, and historical subjects. He is a member of the American Research Society and an Inductee of the Hall of Fame of Automatic Control, besides also being an honorary member of a number of technical societies. Read Dr. Hans Baumann's Reports — More Here.