The heliostats in solar power plants consist of several mirror modules that reflect the solar irradiation to a receiver on the top of a solar power tower. They are slightly concave and track the sun biaxially. The highest concentration of radiation is reached when the heliostats are placed in a position where the sunlight is reflected to the focus of the solar receiver. The result is a solar radiation with a concentration level that is approximately 1000 times higher than natural solar radiation.
The heliostats stand for about 45% of the total investment costs of a solar power tower. Therefore, an important objective is to reduce the costs for their production and operation.
In the research made independently by DLR, as well as in the cooperation with heliostat producers, the following aspects are important to consider in order to reduce the costs: