(ANSAmed) - ROME - The most innovative solar energy plants have futuristic forms. The solar plants of the future, with their mirror-dishes and towers that collect energy, look like a scene from a science fiction movie. One of these installations will be built in Africa as part of the 'Desertec' project. The twelve interested companies and the 'Desertec' foundation signed an agreement on the project in Munich on October 30. The website of NewScientist shows some photographs of four possible types of solar plants to be used for the project, explaining the advantages and disadvantages of each type. - The American National Solar Thermal Test Facility in Albuquerque, New Mexico, was built using giant solar disks that reflect sunlight to an arm at the centre of the disk. At the end of this arm, a receiver collects the heat. This layout offers the possibility to have the disk track the sun. It is also able to operate at very high temperatures. A modular structure, it is easily expandable and doesn't require much water. It cannot store heat on the other hand, so it will not supply energy when the sun is not shining. - The Sanlucar la Mayor plant in Seville, Spain, known as PS10 and built by the Spanish firm Abengoa Solar, is designed as a giant 'monolith' that collects the rays of sunlight reflected by 624 rotating mirrors. The tower is 115 m high and contains a receiver and a turbine to produce power. This plant also operates at high temperatures, and it does store energy. It also requires an enormous quantity of water on the other hand. Another disadvantage is, that only very large plants are efficient from a financial viewpoint. - The plant in Bakersfield, California, known as Kimberlina and built by Ausra, is a giant field of solar panels. The panels heat water and the vapour that is formed moves turbines producing up to 5 Megawatts of power. This type of installation is relatively cheap and can be adapted to store energy. They are also less efficient and require much water. - Nevada Solar One, in the Nevada desert, is a giant dish that produces 64 Megawatts of power, enough for 14,000 households. Built by the Spanish Acciona, Solar Power includes 760 dishes with 182,000 mirrors that focus the rays on pipes filled with oil which heat up and produce steam from water. The system is commercially available, it stores heat and therefore also supplies energy when the sun is not shining. It also needs large amounts of water on the other hand. (ANSAmed).