Actually, it can actually be more efficient depending on your climate. If you have cool nights and hot days, you make the ice at night and take advantage of it already being cool, and that makes up for the larger temperature drop to below freezing. This is harder if you want to be solar powered, as you must make your ice in the morning when it is warmer. Some Ice Bear solutions get a bit over 100% efficiency.Ice storage is mostly a commercial thing and has been around for quite a while. I don’t think I’ve come across any residential installations. They’re more complicated and overall less efficient, as they require additional equipment, pumps and water treatment. That said, they might have a place in homes in the future.