These figures are from Wikipedia https://en.m.wikipedia.org/wiki/Energy_density
The fundamental problem is weight and volume of alternatives. Example Nissan leaf 40Kwh battery 303kg
Hydrogen.
6.8MJ per Kg
High-pressure tanks weigh much more than the hydrogen they can hold. The hydrogen may be around 5.7% of the total mass,[19] giving just 6.8 MJ per kg total mass for the LHV
assume 700 bar has cylinder 9800 PSI
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Diesel
45.6 MJ per Kg
Batteries. (lithium-ion battery)
0.875 MJ per kg
1kg of diesel has the same energy as 50kg of batteries or 8kg of hydrogen at high pressure.
Assuming 25% conversion rate for diesel IC engine under load.
1Kg diesel when used in IC engine is equivalent to:-
12Kg of batteries
2 to 3 kg of hydrogen. (Assumed 80% conversion rate H2 to electricity)
The fundamental problem is weight and volume of alternatives. Example Nissan leaf 40Kwh battery 303kg
Hydrogen.
6.8MJ per Kg
High-pressure tanks weigh much more than the hydrogen they can hold. The hydrogen may be around 5.7% of the total mass,[19] giving just 6.8 MJ per kg total mass for the LHV
assume 700 bar has cylinder 9800 PSI
[/URL]
Diesel
45.6 MJ per Kg
Batteries. (lithium-ion battery)
0.875 MJ per kg
1kg of diesel has the same energy as 50kg of batteries or 8kg of hydrogen at high pressure.
Assuming 25% conversion rate for diesel IC engine under load.
1Kg diesel when used in IC engine is equivalent to:-
12Kg of batteries
2 to 3 kg of hydrogen. (Assumed 80% conversion rate H2 to electricity)
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