I would recommend vertical turbines as being an economical solution for seasteading.
My thoughts about windmaills are to maximise benefits while reducing materials used and energy expended. To this end, I would place an “archimedes screw” on the turbine axis to lift water into a storage cistern. During periods of low energy availabilty, it is simple to release some of the stored water to generate electricity (microhydro).
A Newscientist article [fighting fire with a steam machine – 06 March 2004] describes a fire fighting hose nozzle that doubles up as a “engine” (method of propulsion). It is powered by steam so that sunlight and seawater, two abundant resources for seasteaders, can provide a ‘free’ (neither economic nor environmental cost) technique to move around the oceans. The ‘motor’ has no moving parts and seems to be cast in one piece – minimal maintenance and easy replacement.
I have just read “Sea Energy Agriculture: Nature’s Ideal Trace Element Blend for Farm, Livestock, Humans” by Maynard Murray, MD . This book suggests that seawater (within some specific criteria) can be diluted to 9% with fresh water, NEVER distilled water, to provide the perfect hydroponics solution for superior agriculture results.