Case Study For City Planners: LED vs HPS Street lights
In our previous article, we highlighted the differences between LED vs HPS street lights and why LED street lights make more economic sense for governments and city planners in the long run.
The truth is that not all street lights are made equal!
But, our word is only as good as the evidence we can use to back it up with.
With that, we present you with a case study that includes a head to head luminaire comparison and technical analysis of LED vs HPS street lights to illuminate the differences between a 88W LED street light and a 150W HPS street light in street application.
Safer roads, higher energy efficiency and a significant reduction of long-term costs and your city’s ecological footprint starts with these findings.
CONTENT
1. Visual Results of LED vs HPS Street Lights
2. Technical Analysis of LED vs HPS Street Lights
3. Isoline Analysis of LED vs HPS Street Lights
4. Table of Results of LED vs HPS Street Lights
Visual Results of LED vs HPS Street Lights
Luminaire 1 Luminaire 2
– 88W LED Street light – 150W HPS Street light
– L758xW332xH167mm – L768xW380xH280mm
Street view with applying luminaires
Street view with light distribution curves
Street view with luminance isolines
Technical Analysis of LED vs HPS Street Lights
Luminaire 1 Luminaire 2
Lamp: 88W LED Street light – 6500K Lamp: 150W HPS Street light
Luminous flux (luminaire): 9615.84 lm Luminous flux (luminaire): 11548.68 lm
Luminous flux (lamp): 9616.00 lm Luminous flux (lamp): 15000.00 lm
Luminaire Wattage: 87.8 W Luminaire Wattage: 169.0 W
W/km: 6321.6 W/km: 12168.0
Arrangement: both sides opposite Arrangement: both sides opposite
Pole distance: 28.000 m Pole distance: 28.000 m
Boom inclination (3): 0.0° Boom inclination (3): 0.0°
Boom length (4): 1.000 m Boom length (4): 1.000 m
Light centre height (1): 8.000 m Light centre height (1): 8.000 m
Light overhang (2): 0.000 m Light overhang (2): 0.000 m
Results for valuation fields Results for valuation fields
Light loss factor: 0.67 Light loss factor: 0.67
Roadway 1 (ME3c) Roadway 1 (ME3c)
Light output ratio: 99.99% Light output ratio: 76.99%
Lamp luminous flux: 9616 lm Lamp luminous flux: 15000 lm
Luminaire luminous flux: 9615.84 lm Luminaire luminous flux: 11548.68 lm
Power: 87.8 W Power: 169.0 W
Luminous efficacy: 109.5 lm/W Luminous efficacy: 68.3 lm/W
Colorimetric data Colorimetric data
CCT 6500 K, CRI 80 CCT 6500 K, CRI 40
Check out our LED vs HPS infographic.
Isoline Analysis of Led vs HPS Street Lights
Luminaire 1
Luminaire 2
Table of Results of LED vs HPS Street Lights
Luminaire 1 Luminaire 2
Conclusion
The test case of the first luminaire (88W LED Street light), presents key advantages over that of the second test case luminaire (HPS 150W Street light).
This first case provides a more efficient solution, which leads to lower energy consumption and thus lower cost at an annual basis.
The lamp and luminaire luminous flux values of the first case may be lower compared to that of the second case, but the luminous efficacy and power values of the first one show a more efficient solution in terms of consumption and thus operating cost.
The LED technology ensures lower consumption in principle, but the technical analysis provided is the clear proof that the first test case is leading to a more sustainable solution for the investment’s finance as well as the environmental impact.
The technical requirements set for this type of roadway (ME3c) are not met by both cases. At his comparison test, the first test case provides a compliant solution compared to the second case, where the UI requirement for the study is met only by the first case.
Additionally, the luminance requirement (Lm) is met by both cases on average, but as shown in Isoline Analysis, not all the values are above 1 cd/m2. For these reasons, only the first case would be accepted as a solution in this street light application.
Speak to Provident today to discuss your city network’s unique needs to select the most optimal LED street lighting solution today!
