Oh dear. Maybe I should be clearer. 1) The scale of the existing kerosene system is a liability to your scheme such as it is, not an asset, because both need t

Oh dear. Maybe I should be clearer. 1) The scale of the existing kerosene system is a liability to your scheme such as it is, not an asset, because both need to exist in parallel. You cannot reuse it. Costs are additional for any transition period, and can easily be high enough to make transition impossible. 2) The scale of the kerosene system is thermodynamically irrelevant. The relevant scale problem is that you need double-digit gigawatts available to planes on demand and on-site. That's the whole game. Where you put the solar, wind, or nukes to make that happen is your problem, not mine, but I can guarantee you that transporting XXGW into a single site over transmission line starts to look silly. "Do it at a thousand places on the grid" is a non-starter. That's why I gave you the benefit of the doubt and assumed that on-site was naturally beneficial for your scheme. My mistake, it won't happen again. 3) However you do this, you are doing this in addition to the power generation capability of the rest of the grid. I've talked about one airport. Taking the UK as a whole you need to have a proposal which, give or take, doubles electricity generating capacity for the entire country. That needs more than a dismissive "not a novel observation" jibe. The scale of that challenge means that it's on you to propose how to achieve that as part of the scheme. You have not made such a proposal, rather you prefer to accuse me of misplaced outrage and dishonesty when you have failed to clarify a critical part of your idea adequately. You're handwaving about manual work and implying, I have to assume, that one can take the vast flow of money currently spent on manual labour and use it to bulldoze any inconvenient laws of physics which happen to get in the way. I wish you all the best in that particular endeavour. 4) Either you generate H2 on-site with huge amounts of equipment, or you pipe from elsewhere at pressure. In the former case "drop the equipment where you need it" takes vast tracts of land next to the airport, as I pointed out, in addition to the space the airport already takes up and in competition with the housing (or whatever) that's already there. In the latter you manage high-pressure hydrogen over considerable distances. It's just not true to say there's no difference. Elsewhere you've tried to dodge this dilemma, but you do actually need to pick one. You can't say that the storage and transport problem is fine because you can generate on-site without acknowledging the amount of space that takes up, and you can't restrict piped supply to low pressure because of the sheer quantity of H2 you need to transport. We're done here. The scheme's not practical, you've got no adequate response to the problems with it, and I'm past caring any more.