*Article* **Experimental Study of the Levels of Street Lighting Using Aerial Imagery and Energy Efficiency Calculation**

### **Ovidio Rabaza \* , Evaristo Molero-Mesa, Fernando Aznar-Dols and Daniel Gómez-Lorente**

Department of Civil Engineering, University of Granada, 18071 Granada, Spain; emolerom@ugr.es (E.M.-M.); faznar@ugr.es (F.A.-D.); dglorente@ugr.es (D.G.-L.)

**\*** Correspondence: ovidio@ugr.es; Tel.: +34-958-249-517

Received: 17 September 2018; Accepted: 21 November 2018; Published: 23 November 2018

**Abstract:** This article describes an innovative method for measuring lighting levels and other lighting parameters through the use of aerial imagery of towns and cities. Combined with electricity consumption data from smart electricity meters, it was possible to measure the energy efficiency of public lighting installations. The results of this study also confirmed that lighting measurements, installation material, luminaire position, and electricity consumption data can be easily integrated into geographic information systems (GIS). The main advantage of this new methodology is that it provides information about lighting installations in large areas in less time than more conventional procedures. It is thus a more effective way of obtaining the data required to calculate the energy efficiency of lighting levels and electricity consumption. There is even the possibility of generating street lighting maps that provide local administrations with up-to-date information regarding the status of public lighting installations in their city. In this way, modifications or improvements can be made to achieve greater energy savings and, if necessary, to correct the distribution or configuration of public lighting systems to make them more efficient and sustainable. This research studied levels of street lighting and calculated the energy efficiency in various streets of Deifontes (Granada), through the use of aerial imagery.

**Keywords:** street lighting; energy efficiency; aerial imagery; GIS
