It is always difficult for me to understand why otherwise knowledgeable persons fail to understand that hydrogen based power sources must be considered STRICTLY like a battery now.
Some day, we will have 4H>He and at that time we can really talk about it as an energy SOURCE, but that day is not going to come in my lifetime (though D+T>He conceivably may if I live looong)
4H>He & D+T>He may not be as far off as you expect............