Think about the logistics of mechanical aeration, when compared against pneumatic aeration. Mechanical means moving parts, and the transmission of force required to do the work from surface down to near the bottom....in an underwater environment. Moving parts require adjustments, maintenance, and eventually repair or replacement. Pneumatic aeration involves a flexible hose, and some plastic and flexible membrane diffusers..no moving parts, and if maintenance or repair is needed you simply pull the diffusers to the surface and get after it.
I do think that surface aeration might hold promise for windmill application.
I'm also still sayin' the stirling cycle powered compressor holds promise for aeration!
