Page 189 - AJWEP-22-6

Municipal street lighting retrofit in Bulgaria

A B C D E F

Figure 1. (A-F) Condition of depreciated street and park luminaires

Figure 2. Section of a map sheet showing the plotted locations of the street lighting system in Pavlikeni

Figure 3 presents the distribution by type and power the monthly electrical energy consumption for street
rating of the existing street and park luminaires in and park lighting over the course of 1 year.
Pavlikeni. Street lighting accounts for 83.8% of the The municipality has a permanent population of
installed luminaires, while park lighting represents 22,059, and the specific electricity consumption is
16.2%. In the town of Pavlikeni, however, park calculated at 56 kWh/capita/year.
luminaires constitute 48.3% of the total, whereas their Based on the detailed survey analysis, the following
share in the other settlements is negligible. energy-saving measures are proposed: Replacement of
The predominant type of light source is HPS, the existing street and park luminaires with new energy-
representing 50.4% of all luminaires, followed by efficient LED luminaires of lower installed power,
CFLs, which account for 36.5%. Street luminaires implementation of an intelligent system for lighting
equipped with high-pressure mercury vapor lamps are control system, and optimization of the switching
outdated models, exceeding 25 years of service, and schedule.
are significantly depreciated. In many cases, the lamps
are missing, and only about 5% of the high-pressure 2.2. Street lighting design optimization through
mercury vapor luminaires remain operational. computational modeling
In total, the street lighting system in Pavlikeni 2.2.1. Lighting classification and standardization
comprises 4,663 street luminaires and 901 park Based on a detailed audit of the geometric parameters
luminaires, resulting in a combined total of 5,564. In of the street lighting installations in the individual
addition, there are 5,942 poles without luminaires—5,880 settlements within the municipality of Pavlikeni, it was
are reinforced concrete, 46 are steel, and 16 are wooden. established that significant variability exists only in
The total electrical power of the existing street and the two towns—Pavlikeni and Byala Cherkva—while
park lighting in all settlements in Pavlikeni is 280,153 the remaining settlements are small, relatively uniform
W. Figure 4 illustrates the distribution of electrical villages. This finding justifies the need for detailed
power across the 20 settlements, while Figure 5 depicts classification, standardization, and optimization

Volume 22 Issue 6 (2025) 183 doi: 10.36922/AJWEP025310242