Salt, the common name for the compound of sodium (Na+) and chloride (Cl-), along with water, cereals (bread) and meat of domestic animals, constituted the main commodities of human society in its infancy [Baas-Becking 1931].
Originally, salt was used to supplement the human nutritional needs. However, when its significant food preserving property was discovered, salt became one of the most important commodities for centuries, comparable to the importance of oil in our times.
Humans must have initially found salt, where it can be still found, that is in coastal rock concavities or lagoons, where seawater gets trapped and deposits salt by solar evaporation. It can be reasonably deduced that, after a long period of observation and knowledge building, humans eventually copied nature and began producing salt, in quantities that met their growing social needs.
Producing salt in single basins (ponds) such as coastal rock concavities or lagoons, by solar evaporation of seawater, constitutes the first method ever used by man to produce solar sea salt. We define this method as the first step of the Solar Sea Salt production process evolution. The optimization of this process in terms of quantity and quality of the produced salt, eventually led to the creation of an integrated coastal saline ecosystem! The current Solar Saltworks!
Production of salt from seawater involves the selective recovery of pure NaCl, free of other soluble or non-soluble salts and other substances. To this end, condensation of seawater by solar evaporation results in the fractional crystallization of all contained salts; a process based on their varying solubility in seawater.
Current Solar Saltworks are multi pond systems. They consist of a system of interconnecting lakes in series, properly designed and constructed. The seawater enters (by tidal action or pumping) the first lake in the row and appropriate control gates regulate its flow into the lakes system. The incident solar radiation, assisted by the wind action, evaporates the seawater and develops a salinity vector in the lakes that results in salt crystallization in the latter lake in the row.
Thus, the pond system of Solar Saltworks consists of two main groups. The Evaporation Ponds, where the seawater is concentrated up to the saturation value with respect to NaCl and the Crystallizers where salt is produced.
The annual capacity of Solar Saltworks varies from some hundred to some million tones of salt, depending on the area used and the prevailing microclimate in the region. In seasonal Solar Saltworks the produced salt is harvested once every year and it is stored in open outdoor piles.