Life span of an air compressor has numerous variables. With the right air compressor and size of airline one can push air to a diffuser 1000-2000ft. That air compressor (rocking piston 1/2hp) can then produce twice the amount of air volume compared to the solar one (single head) you listed above. Plus in a 1/2 acre pond the air diffused aerator with the right diffuser system would only have to run 3-5 hrs per day in an average 0.5 ac, 12 ft pond. What is average - a pond not surrounded by trees, decent wind exposure, not full of submerged weeds, not highly eutrophic with average water clarity around 3-4ft.