- Two solar desalination technologies have received extensive testing in the GCC countries: namely, the solar-thermal MED process and the solar PV-RO process. The solar-thermal MED demonstration plant which was built in Umm Al Nar near Abu Dhabi city has been in operation since 1984 and is still working at full capacity producing 120 m3/d of desalinated water using seawater [12]. The thermal energy required by the MED evaporator was provided by a solar thermal collector field of evacuated tube collectors having an area of 1,862 m2. The plant has shown a high degree of reliability and maintainability. The economics of this technology was shown to be favorable in many remote areas where the cost offossil fuel is high