- The Endesa Foundation collaborated in the lighting for the tower of the Virgin Mary, a project that was able to overcome great technical challenges thanks to innovation and the latest technologies.
- The whole tower has LED lights that consume up to 10 times less than those of the conventional type.
- The light temperature of the star is cooler than that of the rest of the basilica, and similar to that of the stars, a difference that has a double objective: Conceptual and artistic.
Yesterday a new star was lit in the city of Barcelona, the one that crowns the tower of the Virgin Mary in the Sagrada Familia. The Endesa Foundation collaborated to make the lighting project for the tower terminal possible, including the star itself, an authentic engineering work of great technical complexity that is also efficient from the energy point of view, whilst still maintaining its conceptual and artistic objective.
The star consists of twelve points and a central core that is a dodecahedron out of which spring the twelve pyramids, which constitute each point. In this dodecahedron there are twelve spotlights, each focussed towards one of the tips. Each spotlight is composed of twelve lamps or beams of light: Eight round the perimeter in the form of a circle, and four centrally placed in the centre of this circle. While the perimeter lamps have a wider beam to light up the interior of the pyramid, the four central lamps project a much narrower beam of light that should reach the end of the tip of each pyramid.
Innovation, efficiency and sustainability
All the lighting in the tower uses this technology. The use of LEDs enables energy consumption to be up to 10 times lower than it would be if lamps or spotlights with conventional technology were used. In figures, the power of each tip is 43 W, so if we multiply this by the twelve tips, we are talking about a total power of 516 W, the same that would be used by a standard blender.
Another highlight of the lighting project is the hue of the star, slightly brighter than the rest of the basilica. The chosen colour temperature, 4,000 kelvins, is more artistic and more conceptual. From the artistic point of view, as the basilica is made of stone, it needs to be illuminated with a warm light of 3,000 kelvins. To get the star to stand out from the monumental complex and differ from it, it really had to have a whiter tone, which also blended with the colours that can be seen on the shaft (ranging from blue to white if you follow the structure from bottom to top). So we have a white star, because stars are white. The colour temperature of stars depends on their physical temperature and these range from the most bluish tones (like the Bellatrix star, at 25,000 kelvins) to the most reddish tones (like Betelgeuse, which barely reaches 2,000 K). Leaving stars to one side, 4,000 K would also be the equivalent of the colour temperature of a mercury lamp.
The challenges of a luminous star located at a height of 130 metres.
It is worth remembering that the star is located at a height of 138 metres; taking into account that it is an ornamental body of glass and steel, it is a considerable height and that leaves it very exposed to weather conditions. This is why its design and final materials had to be decided after passing a number of tests. This led to the transfer of one of the twelve tips with one of the twelve spotlights to a laboratory specialising in ray-proof materials and they were subjected to the discharge of a lightning bolt before the final version was reached.
Another condition that was taken into account was the temperature at which they need to operate. So during the day when the temperature is at its highest, the structure and the spotlights are prepared to be able to withstand temperatures of up to almost 80 ºC when turned off. It should be borne in mind that, being a glass body and despite the ventilation systems in place, it is still very much like a greenhouse that concentrates heat on the inside. At night, to undertake checks with the spotlights turned on, 42ºC was taken as a reference, the maximum temperature recorded in Barcelona in a single night. As a result they were designed to have an operating regime of 50 ºC, that is, to reach this temperature inside while switched on.
Fluid dynamics studies were conducted to see the temperature and humidity ranges commented on and, from these data, the most appropriate technology and spotlights could be selected to be able to work under these conditions. In this regard, despite the existence of certain architectural extraordinary elements in glass and steel, the basic reference for construction were the indications made by Antoni Gaudí himself, who made it clear how everything should be and how his project should be defined.
Another highlight of the lighting project is that it is digitalised. The spotlights have sensors that are incorporated into the general control system for all the lighting in the temple. So if certain parameters are exceeded or any of the spotlights does not operate in the way established, an alarm will go off and action can be taken immediately. They are not only monitored, they can also be remotely controlled.
All this system was already incorporated inside the star at the time it was lifted up with a crane and fitted on 29 November and it now crowns the top of the tower. Special connectors were created to connect the star to the power supply that went up from the tower with the use of easy-to-use plugs. The person who connected the star on the 29th had been trained at ground level, so as to be able to make the connections as quickly as possible. This person was trained in work at a high altitude as well as in electrical concepts and once the star was placed, had the privilege of being able to literally plug it into the current from the inside.
Right from its beginnings in 1998, the Endesa Foundation has contributed to the illumination of major architectural works in Spain as a result of the conviction that providing electricity and light is a unique way of enhancing and highlighting the importance of our heritage. There is a list of 700 illuminated works, distributed throughout Spain, including Medina Azahara (Córdoba), the Basilica of Covadonga (Asturias), the Chapter House of the Cathedral of Toledo, the Cathedral of Santa María (Vitoria) and many others
The lighting processes not only comply with the common sustainability and energy efficiency criteria shared with Endesa and the Enel group, they also capture and multiply the beauty of the monument by providing a new artistic view of our common past and projecting it into the future.
About the Endesa Foundation
The Endesa Foundation's projects highlight the enhancement and preservation of our past through common historical heritage and promote the present and future of our society through innovation and close collaboration with other entities in the third sector. With more than 20 years' experience, the Endesa Foundation helps to shed light on the talent of the most vulnerable groups and sensitivity with regard to their demands in order to progress towards a society with more opportunities for everyone.
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