MinWaterCSP project has developed a new generation of mirror cleaning solution for solar thermal power stations, which can save about 25% water

The cleanliness of the mirror surface of the light field reflector is crucial for the focusing effect of the solar thermal power plant, directly affecting the efficiency of solar thermal conversion and the final power generation of the power plant. Therefore, mirror cleaning is an important part of the operation and maintenance process of the solar thermal power plant that cannot be ignored. Most of the world's solar thermal power plants are built in deserts and arid areas with high DNI values, so how to ensure mirror cleanliness while conserving water resources as much as possible has become one of the key issues of concern for operators.

The cleanliness of the mirror surface of the light field reflector is crucial for the focusing effect of the solar thermal power plant, directly affecting the efficiency of solar thermal conversion and the final power generation of the power plant. Therefore, mirror cleaning is an important part of the operation and maintenance process of the solar thermal power plant that cannot be ignored. Most of the world's solar thermal power plants are built in deserts and arid areas with high DNI values, so how to ensure mirror cleanliness while conserving water resources as much as possible has become one of the key issues of concern for operators.

Due to the significant differences in natural conditions among the project sites where each solar thermal power plant is located, the cleaning frequency and plan for the mirror surface should depend on the power plant itself and the project site. Generally speaking, there are two common solutions for saving mirror cleaning water worldwide: 1. By improving hardware and software conditions, the goal of reducing water consumption can be achieved; 2. Improve cleaning efficiency and shorten cleaning cycles.

Recently, with the support of the MinWaterCSP project, ECILIMP Termosolar from Spain has developed a new generation of cleaning solutions that can be applied to tower type heliostats and trough type parabolic mirrors, maximizing water usage and ensuring mirror cleaning effectiveness. At present, the scheme has been validated in solar thermal projects in Spain and Morocco.

It is reported that ECILIMP Termosolar has developed HELIOS&CURVE cleaning solutions for tower type heliostats and trough type parabolic mirrors. HELIOS has now been updated to two versions: HELIOS B: 4WD (4-wheel drive) version with a water tank capacity of 10.000 liters; HELIOS B plus: 6wd (6-wheel drive) version, with a water tank capacity of 15.000 liters.

These two versions can clean more than 200 heliostats per shift and use an intelligent cleaning algorithm to calculate the exact amount of water required based on the cleaning coefficient before cleaning. In addition, HELIOS can always automatically maintain a vertical position with the ground, ensuring that the cleaning equipment operates in good working conditions.

CURVE is currently the best cleaning solution for trough parabolic mirrors. It also adopts intelligent cleaning algorithms, which can optimize water consumption to the maximum extent and cover the surface of the parabolic trough 100%.

The calculation results of the above two schemes show that the HELIOS&CURVE scheme can reduce the use of spray tools by 25%, and the average water consumption is 0.65 liters/square meter; By reducing the use of brush tools by 35% (the average water consumption of brushes is 0.45 liters per square meter), the goal of reducing the amount of water used for mirror cleaning by 25% has been achieved.