By far the largest ongoing costs of a thermo-solar power plant are the maintenance, cleaning and repairs of the solar mirrors. Tower power station The picture shows very impressively how enormously time-consuming and water-wasting the cleaning of thousands of heliostats of a tower power plant is. In addition, there is the constant repair work on the complicated electromechanics of each individual mirror. Trough power station The large sensitive parabolic mirrors are particularly difficult to clean. The picture clearly shows the problems caused by the filigree holder of the glass receiver tube. Many kilometres of mirrors have to be cleaned in this way without bending the sensitive mirror substructure. The water consumption is immense, especially where there is hardly any water. SOTA-DOMUS Fresnel power station The flat structure of the Fresnel fields can be seen very well here. At night, the linear mirrors are rotated by 180° and turned into the night position. In this position, they are cleaned fully automatically overnight by a cleaning robot and the reflectance is scanned at the same time. Any damage is immediately detected and the mirror can be replaced in a few simple steps. This ensures that the solar system always maintains the highest efficiency. The cleaning and monitoring robot uses extremely little water, as the water is purified in the robot and used in the cycle. The huge mirror field is operated fully automatically, the cost advantages compared to the tower and trough power plants are immense.