Albany Solar Farm, page-11

There's a plant like this being evaluated for the Spencer Gulf. Whether there'll be the need for a salt barrier will depend on the geology of the site I guess (porosity of the rocks etc). If the area is just sand hills/dunes then yes it could be a big issue, but I'd guess it's pretty solid rock if it's able to support wind turbines. Albany itself looks like it's built on granite - pretty solid and impermeable, and the Sandpatch coastline looks lie it's pretty rocky (and would get a hell of a lot of salt spray from the roaring forties so the local vegetation must be pretty salt-tolerant.)

https://www.energyaustralia.com.au/about-us/energy-generation/energy-projects/pumped-hydro