Ann: NZ Investor Presentation, page-67

compression/ storage rate is dependent on carrier molecules and temperature of storage. that's why hydrogen is seriously considered. It's ignition safe in ammonia carrier form when low energy densities are suitable and has 75% recovery after cracking. H2 is actually far more dense and efficient to use in planes over jet fuel, but requires cryogenic tanks to condense hydrogen to liquid form, costing energy. Even still, the energy recovery is still very good but requires fleet transport upgrades. upside is that much of this is offset at high altitudes due to energy differential, atmospheric temperatures at 35,000ft are -51deg C