Saving energy while maintaining the feeling of safety associated with urban street lighting

Street lighting (SL) forms a major share of municipal energy consumption and should thus be energy efficient. However, question of how much energy can be saved on SL without compromising on the feeling of safety (FoS), which SL helps to provide for pedestrians, poses a major challenge. To tackle this challenge, in this study, we attempt to determine the amount of energy that can potentially be saved by a proper selection of SL attributes, such as light color and uniformity, while preserving FoS by pedestrians. As the study indicates, using warmer lights and increasing light uniformity can result in 30-50% energy savings on SL. Using this assessment, we estimate that for medium-size cities with population of 200-400 K residents, energy savings on SL can reach 8-23 MWh per annum, which is equal to the output of a small-to-medium-size power plant. As we conclude, the study findings help to design more efficient SL systems that can promote urban residents' well-being, while saving energy and contributing to a cleaner and more sustainable urban environment. To the best of our knowledge, this study is the first that shows that energy on SL can be saved by using warmer lights and increasing light uniformity, while preserving a reasonable level of FoS.

Automated summary

By using warmer lights and increasing light uniformity, energy savings of 30-50% can be achieved on street lighting. For medium-size cities with 200-400 K residents, energy savings on street lighting can reach 8-23 MWh per annum, equivalent to a small-to-medium-size power plant output. This study demonstrates that energy can be saved on street lighting while maintaining a reasonable level of safety.