Imagine living in a village Italian nestled in the middle of a mountain valley on which, in winter months (for about 80 days a year), the sun never shines. What would you do to still have natural light in the town? It is the question that the inhabitants of Viganellaa fraction of Borgomezzavalle which rises in the Antrona Valley, in Piedmont. Think that its inhabitants have found the solution to the problem by building a large mirror on the upper part of the mountain side which rotates in such a way as to bounce the sun’s rays up to the town square. Viganella was thus able to change the “natural” lighting of its territory. Let’s delve deeper into this curious and ingenious idea.
The hamlet of Viganella and exposure to the sun
The small town of Borgomezzavallein the Piedmontese province of Verbano-Cusio-Ossola, includes an even smaller fraction, that of Viganellawhere they live just under 200 people. Like many others in Italy, this hamlet is located in an area with less than favorable conditions, halfway up the slope of a narrow, dark valley. But what makes Viganella’s case certainly more curious are the characteristics ofexposure to the sun. The small village, in fact, between mid-November and the first days of February always remains in the shadow: the position halfway up the hill, under the steep slopes of the mountains, does not allow the sun’s rays to directly reach the town in the coldest months of the year.
Every year, therefore, the inhabitants of Viganella must expect more eighty days of darkness. Obviously we are not really talking about darkness, as in the case of the long Arctic nights but, simply, the small hamlet, for geographical and astronomical reasons, remains in the shadow of the surrounding mountain walls in that precise period of the year.
Viganella’s mirror: how much it cost and who designed it
There solution to overcome this problem is rather recent, in fact it dates back to 2006and it is as “simple” as it is brilliant. A large rectangular reflecting steel mirrorwith a surface area of 40 m2 and a weight of approx 11 quintalswas transported by helicopter to an altitude of 1050 m and positioned on the same slope on which the village is located. Supported by an imposing base of iron and reinforced concrete, this “artificial sun” is therefore found in an elevated position, on the vertical of the same hamlet of Viganella, 500 meters above the roofs of the houses. The solution was designed by the architect Giacomo Bonzani and it cost approx 100,000 euros.
The position of the mirror was determined based on attention topographic analyses, climatic And astronomical and the reflecting surface rotates slowly to follow the movements of the sun and always reflect the light towards the same position: the square of the small town centre.
There maintenance of a structure of this type is predictably a lot complex and the costs are high. For these reasons the Viganella mirror has not always managed to remain in operation to guarantee adequate “sun exposure” even in the months in which the hamlet is in the shade.
There media resonance of the project was remarkable: reports and articles were broadcast by television networks and newspapers all over the world: from Al Jazeera al New York Times and initiatives similar to those of Viganella have also been put into practice in other countries, such as for example in the Norwegian city of Rjukanlocated in an area with a morphology similar to that of the Piedmontese hamlet and today illuminated by three different mirrors.
