Today I read white paper from Philips about performance of street lights. The light sources are LED, High Pressure Sodium and Mercury Vapor. The datasheet is as follow:
I am not sure when they test these. It may be Auguest, 2008. From the above data, we can find the following results.
- Lower power consumption – LED street lights (67W) slash energy use by 52% over Mercury Vapor lamps (138W) and 26% over a high pressure sodium lamps (90W)
- Higher efficacy (50 lm/W) – LED street lights exceed mercury vapor’s 31 lm/W. You can find higher efficacy measurement from for high pressure sodium lamps. It is just misleading because It includes wastedlight that in turn wastes energy.
- More Lux per watt (0.21) – more than double that of a mercury vapor street lamp.
**The equivalent measurement for high pressure sodium lamps is skewed by hot spots that bump up the lux rating but cause undesirable visibility, safety and glare problems.
- More even light distribution (0.40) than both of High Pressure Sodium and Mercury Vapor. As indicated by the ratio between the minimum and average lux produced in the target zone. The LED scenario was the only one of the three to match the European street lighting guidelines on this uniformity measure. because of its ability to precisely direct light.
- Longer lifetime (60,000 hours) – Lifetime of LED can be translated into a 10 to 15 year life expectancy. However, the lifetime of LED streetlights also depends on other parts of streetlights. In contrast, conventional street lamps burn out after 3 to 5 years, incurring higher manpower and related maintenance costs for bulb replacement.
So I believe that LED street lights are coming soon to you. You can find our LED street lights here http://www.ledlightsorient.com/street-lights-c-8.html