Interview Michel Goutal

When we became aware of this project, right from our first look at the systems, the Historical Monuments Committee commenced a direct dialogue with Toshiba engineers in the pursuit of further improvements. We discussed viewing angles and the position of the lighting systems having regard to the building's architecture.
An interesting facet of LEDs is that they are configured in bars. A problem that occurred in the initial tests was a space between these bars which was rather conspicuous and gave a dotted line appearance. Toshiba made modifications to reduce the coupling between the bars until it was invisible. These major improvements produced perfect continuity and we now have light diffusion across the facades that achieves great uniformity compared with previous illumination systems.
The Louvre's architecture has large, linear cornices. Immediately behind the brightly illuminated sections are darker sections. Finding some very good angles during testing produced excellent uniformity of illumination over all facades and also resulted in an interesting colour temperature. It is not quite as warm as the previous system but still achieves an excellent result.
This technology will clearly grow as the lighting fixtures have a linear design which lends itself to installation on cornices. The units can also be fixed to low sloping roofs and illuminate while being masked by eaves or gutters. That makes it a very interesting solution.
There is no doubt that this project will achieve considerable energy savings. One direct result is the advantage of being able to use these illumination systems for a long time compared to the past. The illumination systems in most historical monuments are turned off relatively early in the evening. If we can realise energy savings we can also think in terms of cost savings but we can also consider extending the duration of illumination. It might be interesting if we could illuminate certain monuments for longer than in the past; say for example in the period between midnight and two o'clock in the morning.