This is also sometimes confusingly called "sea salt". It is not, however, the same thing as the sea salt found in food stores. Most importantly, it is *not* food grade. It's main purpose is for use in water softeners, sold in 40 pound bags. The reason it is called "solar" and sometimes "sea salt" is that it is produced by evaporation of sea water in large ponds in various arid areas of the world. This salt type is not purified and still contains the desiccated remains of whatever aquatic life might have been trapped in it. Those organic remains might react with the proteins in the foods you are attempting to preserve and cause it to spoil. Use canning salt instead.
Solar salt is being tested in energy conservation and preservation of energy that is generated by some renewable sources as an alternative to batteries. Salt is stored in underground stainless steel containers, and is melted with the excess peak power to a high heat. That heat can (by utilising thermodynamics) be saved for hours and then reused in generators (slowly dispersed during the night or windless periods) upto a time period between 6-24 hours. Can also be utilized to produce cooling effect in large buildings.