Thanks for your comment.

You are right about the difference between comparing the bulk properites of energy storage materials and their overall system impact.

For this reason, rather than try and decide what should or should not be included in the system comparison, after the bulk properties were compared, a comparison of equivalent enitre vehicles was done, showing that at light duty passanger car scales, the net result is a moderate advantage for hydrogen in mass, and similar practicality for volume. As noted, the mass advantage for hydrogen gets significantly strongly as vehicles get larger, and larger vehicles tend to not have as serious volume constraints.

Regarding your comment about the shape of batteries vs. tanks, we previously sponsored R&D by Otherlab https://www.otherlab.com , which spun out into the company Volute: http://voluteinc.com on hydrogen tanks that are long and skinny, and can be folded like chains of hotdogs to conform to intricate spaces in vehicles as you say. Interestingly, long narrow diameter cylinders actually perform better than short large diameter cylinders, though the former are more complex.

Most BEV manufacturers have gone to putting batteries as low as possible in the chassis because they weigh so much, and a low center of mass is desireable. This is less of an issue with hydrogen, particularly with novel tanks.

Thanks again for your insightful comments.