Pretty clever idea. Sadly uneconomical when compared to desalination because I love the idea of iceberg calf hunting. Ripe for a novel Moby Dick - The target is already a large white object. Call me Icemael.

Got a bit of a Cold War era pykrete like project feeling.

Given enough solar/wind/battery power i do wonder if a desalination plant could run pretty cheaply. A quick chat with ChatGPT tells me it should be feasible. Roughly investing around 1 billion dollars and around 40 million per year for keeping it run producing around 100.000 m³ per year. Cost price of the water would be around $0.20 per m³. Could run for more than 25 years.