Producing Hydrogen and Ammonia requires to put energy including a level of inefficiency.

For Hydrogen by electrolysis of water

• Theoretically 39.4kwh/kg of Hydrogen (specific energy)
• Currently about 50kwh/kg (source)
• 41.5 kwh/kg of Hydrogen based on hysata 95% currently maximum efficiency which includes some external heat absorbed as the process is endothermic (source 1, source 2)

For green ammonia (NH3) using green Hydrogen and exluding Nitrogen production: 17kg of ammonia can be produced using 3 kg of hydrogen

• Theoretically 6.95kwh/kg of Ammonia
• Currently about 8.82kwh/kg Ammonia
• 7.3 kwh/kg using hysata current maximum efficiency