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Comment by eh_why_not | Hacker News Reader

> The mirror was designed by Bozani with the help of engineer Gianni Ferrari, and cost about €100,000...

First reaction: why would a mirror cost this much?

> Eight metres wide and five tall, it reflects the sunlight for six hours a day, following the sun’s path in the sky thanks to a software programme that makes it rotate.

Also saw elsewhere that the reflectors are made of steel. So a giant, software-controlled, motorized structure, reflecting just the right amount of sunlight to a precise location, sitting out there in the elements...

Totally worth it, and what a cool project!

Relevant: https://en.wikipedia.org/wiki/Heliostat ("Aziz, Light!")

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The hardware may cost very modestly. But consider the salary of the people who designed it, built it, transported it, and installed it. These must be several pros, working on that full-time, at a salary near the competitive level (even if they agree to take a hit out of being charitable). Much of that salary would go to the taxes.

I began designing a kirigami-based orientable "parabolic" mirror-mesh with the goal of creating an affordable solution. My primary design objective was to minimize the number of actuators relative to the number of "pixels" in the mesh, enabling me to control the position of the focal point using just a few servomotors. The project originated as an exploration of redirecting sunlight onto plants by mounting these mirror meshes on my house walls, though I did not complete the design.

The actuating system I developed can tilt pixels in a row at an angle proportional to their distance from the mesh center. This approach creates a "focus parabola" rather than a precise focal point—which would require actuators to tilt pixels according to an arctangent function relative to their center distance. Despite this limitation, I believe the design remains viable for my intended use, notwithstanding the significant incendiary risks involved.

While this approach might not be suitable for the scenario discussed in the article due to wind conditions and the need for a flat surface, it offers advantages over costly hydraulic systems. The mesh could be rolled up and transported in a bag, providing a potentially more portable alternative.

Interesting. It's hydraulically controlled -

https://youtu.be/kWiilCH1AO0?si=PxE3UuB9DE9sB0Hq&t=124

Norway's Rjukan seems to have implemented it better

https://www.youtube.com/watch?v=1PbAsci1D0k

"It's a Ferrari!"

"It's a steel box!"

This reference was such a classic for years after the release of the Fifth Element!

my thought was the opposite: "only EUR 100k for a giant sun tracking device mounted above a village? Maybe Montgomery Burns' idea of doing the same thing in reverse wasn't so ludicrous after all..."

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