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I was with you until no hydrogen. While it is inefficient in compared to batteries, as long as it is being produced with carbon-neutral energy then there are ar
by eightysixfour 5y ago
I was with you until no hydrogen. While it is inefficient in compared to batteries, as long as it is being produced with carbon-neutral energy then there are areas where its kWh/kg ratio and comparatively rapid refilling are extremely beneficial.
- yholio 5y agoYou should take that kWh/kg figure with a kg of salt. You need a heavy COPV tank to store hydrogen under pressure, a 100 kg tank might store only a few kg of fuel, take 400 liter to do so, and be comparable with a 30l conventional fuel tank: https://www.fsec.ucf.edu/en/consumer/hydrogen/basics/documents/task2_gaseous_h2.pdf https://www.fsec.ucf.edu/en/consumer/hydrogen/basics/documen...
- eightysixfour 5y agoSure, and using it for small vehicles seems like the worst place to use them. I'm thinking more about vehicles that need significantly more fuel - diesel electric trains, container ships, airplanes, etc. It won't work in all of those situations since hydrogen is so hard to manage, but there are a number of applications where batteries are not the right answer yet. Battery weight is going to scale close to linearly with capacity, hydrogen tank weight should not.
- ncmncm 5y agoLH2 tanks on aircraft, insulated with aerogel, can be very light. But the extra volume will mean a need for new airframes. Trains and ships, and maybe trucks, will do better with ammonia. The tanks are bigger, but those have room, and existing engines can burn ammonia with just changes to plumbing.