Promote? Trying something out and finding that it works is not much of a promotion. The entire aviation sector, both commercial and military, is looking for sustainable, low carbon or zero carbon fuels for thereby lies long term survival. Anything that points that way is useful. If the UK can develop an indigenous industry manufacturing said fuels, so much the better.

https://www.oref.co.uk/orkneys-energ...3%20%26%202014.

Orkneys net exporter of wind generated power they were having issues putting in the grid to deal with it.

From you link, it seems the lack of grid capacity in Orkney is limiting the installation of more power turbines at present. That is not an argument for not making fuel from wind or tidal power. Interestingly, the Surf & Turf project in Orkney is using excess generating capacity to manufacture hydrogen that is used in other projects, such as powering one of the inter-island ferries. In fact I missed any mention Zero Petroleum in the link you furnished.

Yes, promote. What else would you call an aircraft photographed with Zero Petroleum and RAF decals being flown over Kemble airfield by an RAF Gp Capt wearing an RAF flying suit other than promotion? Trying it out to see if it works? LoL, just as well for him that it does then!

Civilian registered aircraft - registered to Kemble Flying Club. RAF logo tick, but RAF decals no. Also Zero Solutions logos. If I were to guess i would say there is a degree of sponsorship going on.

Interesting comment. Who would be sponsoring who?

Well, if I were to guess, the aeroplane.

Sorry, old boy, not quite getting your drift. There are four possible parties involved here; Zero Petroleum, The Royal Air Force, Kemble Flying Club, and now the aeroplane? The Ikarus C42 with its Rotax 912UL engine? Are you saying that airframe and/or engine manufacturer has a dog in the race?

Seeing as we are guessing, wouldn't the more obvious culprit be Zero? Whoever you might mean, I doubt it is the RAF, who are fast clearing out whole fleets in back to back fire sales more akin to flogging the family silver than investing in wonder technologies. In any case even if it did have two brass farthings to its name, isn't sponsoring commercial companies somewhat frowned upon? Or is that what is meant by "cutting through the bureaucracy"?

It does seem that G-KFCA's new fame is being exploited to the utmost though :-
https://kembleflyingclub.com/

So who is the sugar daddy here, and who or what is trousering its largesse? Genuinely interested.

I am only speculating but from experience, owning and operating a fleet of club aircraft is not cheap. I did it on more than one occasion in the RAFGSA. If someone had come to me and offered to sponsor one of my airframes and the rules allowed it, I would have bitten their hand off and would have happily put their logos on the aircraft.
I stress, speculation on my part.