This paper analyzes the technical and economic viability and sustainability of urban street lighting installation projects using equipment powered by photovoltaic (PV) energy. First, a description of the state-of-the-art of the technology is performed, studying the components involved in solar LED luminaires for street lighting application and examples of autonomous PV systems installed in different countries. Later, a case study a based on a renovation project of the street lighting installation at a 5000-inhabitant municipality in Lanzarote (Spain) is presented. Two alternatives are analyzed: underground channeling of the previous aerial electrical grid and the installation of LED luminaires, and, on the other hand, the installation of autonomous LED solar luminaires. Simulations concluded that a PV lighting installation proposal guarantees the existing M3 lighting requirements (EN 13201-2:2015) and represents a saving in the material execution budget of 43.78% with respect to the channeled power grid option. Finally, a statistical study has been carried out to assess the social acceptance of Spanish citizens of this autonomous PV technology in urban environments. This considers strengths and weakness of the technology: sustainability, robustness, visual impact, or risk of vandalism. In general, most subjects of all age segments are aware of the problem that means having aerial wiring running at facades (95%) and considers the use of PV in urban lighting sustainable (88%). However, 47% of those surveyed consider that shutdowns due to lack of energy harvesting is problematic and 17% consider this very problematic. This major drawback (visual impact of PV equipment is mostly evaluated as neutral) gives rise to social reluctance, especially in people younger than 50 who remarked this as more problematic than senior segments. Thus, guaranteed operational service is fundamental to have social agreement for PV technology implementation.

Energy saving in street lighting is garnering more interest and has become a priority in municipal management. Therefore, LED luminaires are gradually becoming prevalent in our cities. Beyond their energy/economic saving potential, quality in public lighting installations concerns aspects such as uniformity and glare which must be maintained if not improved in any installation renewal project using this technology. The high light intensity generated in a discrete point in LED packages and its directional nature result in significant deficiencies in these last two parameters. To soften these effects, translucent covers are being used as one of the most common solutions with the drawback of significant light intensity losses. The objective of this paper is to evaluate the behavior of LED luminaire’s polyamide-based optical covers manufactured with a laser-sintered process. These are designed to improve glare and uniformity output, to minimize light output reductions, and to be industrially manufactured with no increment of cost for their lighting equipment compared to conventional transparent polycarbonate solutions. A laboratory and field lighting test study has been applied to different covers with the same LED lamp and luminaire to compare the performance of three different solutions built with different polymeric materials and with different light transmission surface textures. The photometric results have been observed and discussed to demonstrate the ability to significantly improve the lighting performance of LED luminaires—illuminance and uniformity levels and discomfort and disability glare indexes— using an improved optic cover.

Sustainability and energy prices make the use of energy obtained from renewable sources on an urban scale and for isolated local facilities necessary for municipal authorities. Moreover, when the demand of energy is at night, as for street lighting installations, the use of accumulative systems is necessary, which means a major drawback due to a short lifetime expectancy and high cost. The use of batteries can require more than 70% of the budget of these lighting systems and has a critical impact in the project. The problem to solve is finding different renewable energy sources that can produce energy throughout the day, especially during the night, at the same time at which it is consumed. As one of the competences of municipal authorities is water supply networks, this paper analyzes the use of energy recovery turbines within these installations as an alternative to photovoltaic generators. To study the viability and effectiveness of this alternative, the water flows available in the network of a medium-size municipality were monitored and analyzed in depth to assess the amount of recoverable energy. In addition, an energy recovery turbine (ERT) station was set up, installing a bypass around one of the pressure-reducing valves (PRV) of the installation where energy is dissipated without practical use. The results obtained imply that the system proposed has economical and technical viability, is reliable and guarantees full service in all the seasons’ conditions. Moreover, the needs of the energy storage capacity are much lower (~8%) than with solar panels.