3 ms·
What kind of energy density? There is energy density by volume (where it matches batteries, when you ignore all the stuff you need to keep hydrogen at 700bar s
by spott 3y ago
What kind of energy density? There is energy density by volume (where it matches batteries, when you ignore all the stuff you need to keep hydrogen at 700bar safe), and energy density by weight (where it wins pretty handily against pretty much everything).
- dieselgate 3y agoAm not historically familiar with this topic though the attached paper above shows a comparative figure of Specific Energy in terms of Wh/Kg at both 5k and 10k psi Edit: interesting to do the conversion and realize 700bar is just over 10k psi - misunderstood the parent comment regarding "700bar safe" Edit2: further interesting to note how the 5k compression of the hydrogen has _higher_ Specific Energy density than 10k due to _decreased_ pressure vessel requirements
- Retric 3y agoJust be careful with Hydrogen energy density as there’s a huge range of non obvious issues. Compressed you lose a great deal of energy converting it to kinetic energy and weight due to the containers + engines. Fuel cells also need electric motors and ideally a hybrid battery. Cryogenic fuel looks great until you need to have it sit around unused. Embrittlement, volume, cost, and a rage of safety hazards make it unappealing for aircraft or ships. So, my guess is the ideal long term solution barring “super batteries” is some sort of synthetic hydrocarbons that uses atmospheric CO2 but we are a long way from viability there.