Take a 2020 Tesla Roadster, with 620 mi range, remove the back seats & add a fuel cell & tank of hydrogen, could you drive New York to L.A.?


Jeffrey M K

Hydrogen is very energy dense; far more than gas. Fuel cells are getting better. "Depending on the type of hydrogen fuel cell, the efficiency ratio tends to average out around 60 percent of the total amount of energy being released by the process above. However, large-scale hydrogen fuel cells with molten carbonate or solid oxide for their electrolyte membrane can use both the heat and electricity produced for extra efficiency, getting as high as 85 percent." I think with a big enough supply of hydrogen and possibly removing the passenger seat as well it could be done.


Depends on the size of the fuel tank. If the Roadster can go 620 miles off of a 200kWh battery, then to go 2,790 miles, it would need at least 4.5 times that amount of energy, or 900kWh total. That said, the fuel cell system would only need to supply 700kWh of that because of the 200kWh battery. Hydrogen is about 33.3kWh per kg, so you'd need just about 21kg or 297L of liquid hydrogen if the fuel cell is nearly 100% efficient. But closer to reality would be, say, it's 50% efficient. So then in reality you'd need 42kg or 594L of liquid hydrogen to produce that 700kWh of energy. That's not very heavy. But unlike fuels like gasoline and diesel, it would take up a lot of space, and you'd need a thermal flask that big so it doesn't all boil out by the time you get part way along the journey. But still possible to fit in the rear seat area. Things don't quite pan out if it's compressed hydrogen. At 30MPa you'd need about 1,867L of storage capacity. The weight of the hydrogen would be the same, but that's a whole lot of space being taken up inside the vehicle, especially considering it has to be contained in a pressure vessel that's capable of holding that kind of volume and pressure. The pressure cylinder would also cause way too much weight, so it looks like liquid hydrogen is your only option. Another concern would be the size and weight of the hydrogen fuel cell. But this doesn't have to be very big. You'd only need about 15kW continuous production to go highway speeds, and that size can be made quite small and compact in size. Conclusion: If you use liquid hydrogen in giant thermal flasks and a 15kW fuel cell, then yes. It would be possible to remove the rear seats, fit those in there, not overload the car's suspension, and have enough energy to drive from California to New York on a single charge and single tank full of hydrogen fuel.




You probably could but you might not make it all the way.


Hydrogen fuel cells have been massively overhyped ... it is why Elon Musk argues against them as a solution. So although doing what you suggest might get you the range, the question I'd ask is what would be wrong with just filling that space in the car with more Li ion battery? That would also work!


NY to LA is 2,790 miles. i would guess no.