I design pressure vessel for a living. At the pressures required for hydrogen, required vessel wall thickness goes up really fast as diameter increases. I comme

I design pressure vessel for a living. At the pressures required for hydrogen, required vessel wall thickness goes up really fast as diameter increases. I commented elsewhere about the weights required for a tractor trailer - to carry the volume required and maintain the same refill range, you'd need an 11,000kg cylinder to contain the hydrogen.