Solar desalination
Solar desalination is a desalination technique powered by solar energy. The two common methods are direct (thermal) and indirect (photovoltaic). History Solar distillation has been used for thousands of years. Early Greek mariners and Persian alchemists produced both freshwater and medicinal distillates. Solar stills were the first method used on a large scale to convert contaminated water into a potable form. In 1870 the first US patent was granted for a solar distillation device to Norman Wheeler and Walton Evans. Two years later in Las Salinas, Chile, Swedish engineer Charles Wilson began building a solar distillation plant to supply freshwater to workers at a saltpeter and silver mine. It operated continuously for 40 years and distilled an average of 22.7 m3 of water a day using the effluent from mining operations as its feed water. Solar desalination in the United States began in the early 1950s when Congress passed the Conversion of Saline Water Act, which led to the establishment of the Office of Saline Water (OSW) in 1955. OSW's main function was to administer funds for desalination research and development projects. One of five demonstration plants was located in Daytona Beach, Florida. Many of the projects were aimed at