Installation of solar panels in the surroundings of tunnel portals: A doubletargeted strategy to decrease lighting requirements and consumption

Abstract

The optimization of the lighting installations in road tunnels has become a matter of the highest concern due to their high consumption in energy, raw materials and financial resources. In addition, they have complex maintenance and high environmental impact due to energy production and manufacturing processes of projectors, wiring and electrical devices. Although the use of solar panels is widely spread in all kinds of infrastructures, they have never been proposed with an intention different from producing clean energy from the solar radiation. In this work, a double-targeted perspective is proposed: the installation of solar panels around the portal gate of tunnels, to contribute to power the tunnel installation (lighting, ventilation, emergency), but mainly to decrease the reflectance of the tunnel surroundings and, hence, the well-known L20, the main contributor to the electrical luminance levels required in road tunnels. The strategy and the measurements in real panels, as well as the savings achieved in one particular model of tunnel (between 18.7% and almost 24%, depending on the use of the generated power), are presented and analyzed in this work.