Today I saw a fluorescent tube fixture panel with 4 tube-slots, and it had individual reflector zones, making the mirrored surface look like it had 3 giant corrugations. This gave me the idea of corrugated parabolic trough mirrors that would have better flexural modulus allowing for thinner sheets of metal to be used, which would be important in a 100 mile x 100 mile area of solar that would generate the equivalent of US energy consumption. Aluminum is too weak and the ideal cheap material in my opinion would be aluminum clad carbon steel sheets, aluminum providing the corrosion resistance and mirror surface. You would stretch carbon steel coils into very thin sheets, then pass them through a molten aluminum bath under argon atmosphere, argon constantly leaking out at the inlet and exit ports from the bath, like argon constantly is blown during arc welding, then one side would be mirror polished, the sheet cut into proper sizes for a corrugation mold press and the paraboloid corrugation imprinted, then the whole thing would be anodized for increased wind blown sand resistance and reflectivity.
The corrugation would be like thus: Imagine cutting a parabolic trough into thin slices across its width, you would have say 1 inch wide U shaped paraboloid strips. Now when you tilt them say 30 degrees to the left and the other to the right, they would touch near the center, the bottom of the U and diverge at the edges, at the top of the U. Because of the focal point being in the tilted plane of the parabola, still at the same distance at 30 degrees offset, the parabolic trough tube would have to come in closer by the cosine of 30 degrees which is 1/2*sqrt(3)=0.866 the original distance. To fill the gap between the divergent edges near the top of the U, you would need triangular flat shapes, but with a parabola that has this same focal length so it focuses on the same tube. Same for the gaps between the bottoms of the Us.
While this would improve the flexural modulus toward the width of the parabolic trough, lengthwise, because of the accordion shape it may not be that strong and may need a rigid truss based backbone running along the length.
A similar idea could be applied to concentrator dishes. You would put dimples into the dish that would each have a closer focal length, but you would orient them so that they all focus on the same point. In between the circular dimples that look like the bottom of a coke can, or make the dish look like a golf ball with dimples, in between these dimples you would have undimpled flat spaces with the original focal point, but to avoid having 2 different focal points you could micro dimple these regions with the same curvature as the main dimples, just smaller surface diameter, and then so on, the spaces between the micro dimples with even more nano dimples, like a fractal. This way you would have a dish with much stronger flexural modulus allowing much thinner sheets to be used in its construction.
A google search comes up with corrugated tubes but not corrugated mirrors.