Optimum Orientation of the Mini-Mirror Array
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The box of the MMA can be oriented freely in two dimensions, i. e. azimuth and elevation angle. For each position of the MMA in a heliostat field, a specific combination of these angles yields the best performance on an annual basis.
As an example,
Figure 7 shows the influence of the box orientation on the annual performance for a heliostat that is located 71m north and 71m east of the tower. The annual reflection efficiency shows a maximum at an azimuth angle of 251.5° and an elevation angle of 36°. This in a reference system where an azimuth angle of 270° corresponds to the box oriented south (east = 0°), and an elevation angle of 0° indicates a non-tilted horizontal box.
In the following calculations, the heliostat under consideration is always oriented to achieve optimum annual reflection efficiency.
