In the context of the electricity crisis, measures are needed to reduce energy consumption. The case study was conducted on the lighting system at a university sports hall. To determine the efficiency and quality, the lighting systems and technical characteristics of the sources used were identified, lighting level measurements were made, the luminotechnical coefficients and the power of the whole lighting system were calculated and the results were compared to the values set out in the standards. Following analysis, the lighting system was found not to meet the quality requirements and was energy inefficient. For financial efficiency, only the replacement of lighting was sought, keeping the same equipment and granting the same facilities to the building users. Some lighting source options were analyzed and the option to have the highest luminous efficacy and the highest energy class was chosen. The analysis shows that the investment is amortized within a maximum of 17 months. The innovative aspect is based on linking the measurements with the determination of power and the proposal of modernization solutions, which shows the need for investments to ensure the quality of the system and the increase in energy efficiency.