It would make sense that in the City of Light, innovative lighting technology has taken center stage at what's perhaps the most revered — and highly trafficked — historic monuments in all of France: Notre Dame de Paris.

Following the addition of nine new cutting-edge — and one would assume Quasimodo-approved — bells brought in to celebrate the 850-year-old tourist magnet’s birthday in 2013, the imposing Gothic cathedral that looms over Île de la Cité has now been treated to a massive incandescent swap-out involving the replacement of old, inefficient bulbs with 400 state-of-the-art LED luminaires. I suppose you could now refer to this famous gargoyle-clad cathedral on the banks of the Seine as Our Lady of the Light-emitting Diodes.

While some may argue that part of Notre Dame’s charm came from its gloomy, atmospheric interiors, which required a bit of eye-straining and jostling in order to view things properly, the LED makeover, carried out by Philips, is meant to better showcase what the millions of visitors descending on the cathedral each year have come to see: the awe-inspiring 13th-century rose windows and vast display of religious iconography and artwork including, of course, the Virgin and Child statue. Philips describes Notre Dame’s new efficient and, perhaps most important, inconspicuous, lighting upgrade: “Never dazzling, sometimes powerful, and always warm, this light creates a reverent atmosphere while still emphasizing the architecture.”

Positioned above the north and south doors, more than 50 meters from the rose windows, two completely invisible 250W spotlights direct their beams onto each rose window, revealing the delicacy of the sculptures. This lighting gives the impression that the stained-glass window itself is radiating light, without altering the monument’s exterior appearance, since the light is only visible on the inside.

In addition to better spotlighting numerous architectural details and art throughout Notre Dame’s interior, the Archdiocese of Paris will enjoy magnifique energy savings: with a new installed capacity of 30 kW down from the previous 140 kW, the new LED system offers improved energy efficiency of 80 percent. In the nave alone, lighting-related energy consumption has been slashed by a fifth according to Philips. Plus, given their lengthy lifespan of 13 years at 10 hours per day, the bulbs will cut back on maintenance costs and the manpower required to do frequent switch-outs.

Notre Dame cathedral lighting

Notre Dame cathedral lighting

Tied to a computerized touchscreen control board, the luminaires are also dimmable so that the “vibe” within the cathedral can be adjusted to better reflect whatever activity might be taking place at a certain time. Explains lighting designer Armand Zadikian: “The Cathedral has two roles, a religious one and a cultural one, with religious ceremonies, visits (almost 14 million visitors in 2013) and concerts. The new lighting was therefore designed to allow different atmospheres to be created depending on these activities."

Plan on visiting Notre Dame for the first time or on a return visit? When you’re done picking your jaw off the floor after you first walk/are pushed in, do take a moment to acknowledge the almighty power of the LED.

And if you prefer to worship at the alter of The Home Depot, Philips’ revolutionary SlimStyle 60-watt equivalent LED bulb is now available at the retailer for $9.97.

Notre Dame cathedral lighting

Notre Dame cathedral lighting

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Matt Hickman ( @mattyhick ) writes about design, architecture and the intersection between the natural world and the built environment.

In Paris, 14th-century cathedral gets 21st-century lighting retrofit
France's most visited house of worship, the Notre Dame Cathedral, just seriously slashed its energy bills with the addition of 400 LED lamps.