Energy saving in tunnels lighting using shading structures

This paper introduces a constructive proposal to save energy in tunnels lighting using shading structures. These structures aim at the reduction of sunlight levels at tunnels portals. Accordingly, such sunlight reduction will reduce the artificial lighting requirements at the entrances and exits and hence provide further energy saving without additional smart intervention using control methods. The aesthetic appearance of shading structures needs to be considered without sacrificing the traffic safety requirements. The energy saving in addition to initial costs reduction render shading structures as a good candidate for permanent installations with low maintenance requirements compared to conventional lighting installations. Our proposal could be applied equally at the design stage of new tunnels and underpasses, or as a retrofit for existing roads structures to turn them into green energy facilities. Renderings and payback calculations predict flourishing future for the proposed tunnel lighting energy conservation by shade structures. This study shows that up to 50% saving in the lighting electrical load can be achieved.