The new design proposes that the mirrors are arranged in a pattern similar to the spirals on the face of a sunflower. With this pattern, the researchers say, the land used for the solar field can be reduced by 20 %, because it is very compact. “Concentrated solar thermal energy needs huge areas,” Alexander Mitsos, Rockwell International Assistant Professor, says. “If we’re talking about going to 100 percent or even 10 percent renewables, we will need huge areas, so we better use them efficiently.” The current layout mirrors are arranged in concentric circles around the tower, whereby the circles are staggered, to minimize shading between them. However, shading with the sunflower pattern is even lower and therefore increases the efficiency of the solar field. The florets of sunflowers are arranged in a spiralling pattern, known as the Fermat spiral that appears in many natural objects. Each floret is turned at an angle of 137° with respect to its neighbours.
The cost saving potential of this arrangement is quite huge, since the solar field is one of the most expensive parts of a CSP plant. It stands for about 30 % of the total investment of a power plant.