This is a public procurement for the renovation of street lightening in the city of Sapareva Banya, Bulgaria.
The City Council, the Mayor of Sapareva banya started the procedure for public procurement for the renovation of street lightening.
In order to define the baseline energy consumption and specify the measures and technical specifications for the street light refurbishment an energy audit was conducted. Two options were proposed:
Replace of the existing luminaries for HPSL with LED luminaries. The existing street lighting control system with photo-cells will be kept. In this case the lamps will work with a constant power during the dark part of the day. The expected savings are 416,786.52 kWh/y or 37310.32 EUR/y additional savings are expected from the lower maintenance cost. The investment cost is estimated at 165,500 EUR with simple payback period 4 years.
This option also proposes replacement of the existing luminaries for HPSL with LED luminaries. In addition control system with possibilities for dimming is proposed as additional 20 % savings are expected. The features of the control system included also online monitoring of the electricity consumption. The savings are estimated to be 447,471.05 kWh/y. The cost of investments will be 231,700 EUR with simple payback period 5.3 years. The greenhouse emissions savings will be 305.62 t CO2/a.
Option 2 was selected.
In the evaluation criteria the light efficiency (lm/W) has 40 % weight, the cost has also 40 % and guarantee and exploitation cost – 20 %.
The investment cost is 227,000 EUR including maintenance for the term of contract – 7 years.
Evidence of success
The expected savings are more than 70% annually as for January 2016 the accounted savings were 80 %.
• annual CO2 savings – 305.62 t CO2/a
• annual costs savings – 40,055.38 EUR/a
• annual electricity savings – 447.471 MWh/a
Potential for learning or transfer
It is important to include green criteria as the light efficiency in order to reach better results. Conducting energy audit is important both to specify the technology to be used and for financial issues as payback time and methodology for saving calculations. LED luminaries with a control system for monitoring and dimming were proposed as the power was significantly reduced and problems with theft of electricity, electrical leakage and others were solved.
Please login to see the expert opinion of this good practice.