The base question of the problem is here. Another related question here.

Additional to the material of the rope, I also need to be able to deal with the said rope when lowering the kite, when the fun gets to an end.

Rolling a few tens or hundreds of meters by hand, might be doable. Rolling a few kilometers of rope by hand, should be a serious physical challenge, I guess.

Additional to the rolling itself, some actual force might be needed to lower the kite, as it might not want to come down. Which complicates the problem even more.

Of course, one solution is to have an entire team of people on the problem - which is far from what I have in mind.

The other solution is to have some kind of help (mechanism?) to help me deal with the problem.

I had an idea about using the wheel of the car for this purpose, but it has several drawbacks. The main con reason is safety related - it is plain dangerous. Also, the car might not be allowed at the site of fun.

I also amused myself trying to find a way to use an accumulator-powered electric screw-driver. The main issue is that it is asymmetrical, the screwdriver being on only one side. And will the accumulator have enough energy? It seems that at least 2 people would be needed in this case also.

Having an entire setup with combustion engines and gears is cool (and more suitable for the Engineering site), but I had in mind something more like "crafting hack". That is why I added the question here. It also does not really fit in the Lifehacks site, unfortunately.