I believe that hydrogen is being looked at a bit, but it presents some significant safety concerns since it needs to be compressed pretty substantially to get g

I believe that hydrogen is being looked at a bit, but it presents some significant safety concerns since it needs to be compressed pretty substantially to get good energy densities. It's my general impression that the safety concerns outweigh the usefulness for the time being. Right now, my organization is focused on a number of hybrid electrical approaches with the main goal being to minimize losses by using the descent phase to charge batteries that are then used to assist in climb on the next flight. I haven't heard about the EasyJet proposal before. I'm looking for more info, but I can't find enough to form an intelligent opinion yet. Interestingly enough, it seems to be a YC backed company that's developing the vehicle.