In this paper, the parameters influencing the installed power demand as well as the installed and normalised power density for road lighting are introduced. The levels of these parameters typical for different road lighting situations are assumed and the resulting normalised power densities for road lighting are derived. A classification system for the energy efficiency of road lighting based on the installed and normalised power densities is proposed. The classification system can be used to compare the energy efficiency of designed and used road lighting as well as forming a basis for an energy efficiency evaluation system for road lighting.

This paper presents an attempt at a unified approach for the assessment of outdoor lighting solutions at the design stage. First of all, the lighting criteria for different types of outdoor lighting installations have been carefully described. Despite the differences in criteria, it is possible to find a common ground for the assessment of lighting solutions at the design stage. This is based on the need for the assessment of lighting solutions to be included in the requirements for the luminous environment, light pollution, and energy efficiency. The review and analysis of the standards and reports allows an experimental procedure to be created, the main aim of which is to find the best and most sustainable lighting solution for any outdoor situation. The procedure was tested by the example of an analysis of parking lot lighting solutions. In the case analyzed, 120 solutions were considered. It appeared that, in only 65 cases were the requirements referring to both lighting condition and light pollution met. Finally, based on the lighting energy efficiency assessment, ten solutions were selected as the most suitable. Furthermore, only one solution out of the ten was the most beneficial, taking into account the extra criterion of basic economic cost. The case study confirms that the assessment procedure allows the most beneficial solution to be selected, taking into account the luminous environment, as well as light pollution and energy efficiency criteria. The proposed multi-criteria assessment procedure may be used as a valuable tool by lighting designers to select the most beneficial solution in order to meet the needs of safety, visual efficiency, and comfort, as well as taking into account light pollution and energy efficiency restrictions.

Lighting technologies developed significantly in the last decade. New LED light sources, dedicated luminaires and improved lighting control techniques gave rise to new possibilities in improving energy efficiency of lighting solutions. The article is an overview of interior, road and exterior architectural object lighting design strategies. It also presents design considerations that directly impact lighting conditions and energy efficiency. Practical examples of the application of basic design strategies, accompanied by the obtained energy results, are also depicted. Issues discussed in the article may be useful in researching and designing interior and road lighting, as well as floodlighting. They can also be useful in planning and implementing strategies aimed at improving lighting conditions and energy efficiency of lighting solutions.