<i>> The mirror was designed by Bozani with the help of engineer Gianni Ferrari, and cost about €100,000...</i><p>First reaction: why would a mirror cost this much?<p><i>> 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.</i><p>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...<p>Totally worth it, and what a cool project!<p>Relevant: <a href="https://en.wikipedia.org/wiki/Heliostat" rel="nofollow">https://en.wikipedia.org/wiki/Heliostat</a> ("Aziz, Light!")