DIGITAL LIGHTING REGULATION
Digital lighting regulation
Digital lighting regulation (or shorter DLR) represents the way in which it is possible to save electricity, and thus the money.
DRR works based on the physiology of the human eye. The human eye needs lighting the most at dusk and at dawn, while at night the eye adapts and there is no need for so much lighting intensity.
In conventional applications, the difference in the light intensity can not be seen with the bare eye. The difference can be seen using Luxometer, a tool for measuring the intensity of illumination, and by low power consumption.
The level of savings depends on the season, the state of climatic conditions and the chosen level of savings.
Example:
Let the lighting consists of 30 lampposts that are powered from the same substation. If the lampposts are distributed to 10 of them per phase, it follows that there are 3 phases (3 phases * 10 lampposts per stage = 30 lampposts total). Each lamppost has a lighting fixture with switching device. Type of the lightbulb is high pressure sodium with 400-Watt, while the switching device is uncompensated electromagnetic with an ignitor. The system is turned on and off remotely via MTU device.
The night lighting regulation is implemented. There are three modes of intensity regulation:
– 100% of power during the ignition and at dawn
– 75% of power from 8 pm with the possibility of adjustment
– 50% of power for 11 pm to 6 am with the possibility of adjustment
For 30 lampposts with bulbs of 400-Watt and 30 switching devices of 44-Watt, total installed power is:
P = 30 ∙ (400+44) W = 13 320 W = 13.32 kW
Annual energy consumption based on the 12-hour work per day is:
W = P ∙ hours of work ∙ number of days = 13.32 kW ∙ 12 h ∙ 365 = 58 342 kWh
Current price of one kWh is 0.58 kn, so it follows that the annual consumption is:
F = W ∙ price = 58 342 kWh ∙ 0.58 kn/kWh = 33 838 kn
Annual savings from work mode shown in schedule on pictures below is between 25% and 30%, depending on the season. With a mean savings of 27.5%, it follows that savings in electricity consumption are:
W (savings) = W ∙ 27.5% = 58 342 kWh ∙ 27.5% = 16 069 kWh
That is, the amount of annual savings in the monetary point of view is:
F (savings) = W (savings) ∙ price = 16 069 kWh ∙ 0.58 kn/kWh = 9 320 kn



