I am surprised that there has not been much discussion on kites as a dynamic positioning system. They are more economical than sails on the scale needed for a seastead…
yes they have been small scale tested – but not yet widley adopted – although their fuel saving properties seem to be quite impressing.
The system of launch / recovery is a quite complicated mecanics that does not come cost and maintenance free – also you need a computer controlled winch in constant movement to keep it flying, the UV deterioriation on fabrics, wear and tear will assure a short lifetime of the sistem – what means a high cost of operation.
The fact that although commercial sales are open – no commercial fleet has adopted the sistem yet, seems to point in the direction that they perfer to deal with the fuel costs instead of dealing with the operation cost and complications of a kite.
Ships are high operation cost and high maintenance cost sistems a cost of operation of 80.000 USD /day is a normal feature – so if they can not afford to fly kites as we speak on a large scale – i doubt a seastead that has to be a ultra low operation cost sistem by nature of its business can use them sucessfully.
On the other hand – we should probably keep an eye on how kite sistems develop in the future – interesting developments may always come up…
The most promising use would probably be a deeploaded seastead of the semisub or plate type that would offer very little wind profile – so it would move 95% with the current. If you place it in a gyre for lazy station keeping – you might have kites to fly just a few days a month for minor course corrections. A kite sistem could last decades this way.
At high altitudes the wind is usually much greater. Floating/flying wind generators are possible but the possibility of a cable breaking and cutting a huge line in the landscape below has kept them from being used.