Well that depends on how equipped you are. One cool thing about compressors is you can straight up connect a PV directly to a compressor with no voltage regulators or anything. So if you have a simple setup like that, I can see cost effectiveness in storing ice. But if you already have batteries, and thus voltage regulators and all the intermediate components to make that possible, then I would agree… I might rather store it in lead acid batteries as that would be more versatile.