25 Nov LED vs HPS Street Lighting
LED lighting solutions have never been more accessible or affordable than now. With multiple rebate programs and incentives, more cities are making the switch to LED street lighting. And why wouldn’t they? As we all know by now, LEDs are energy-efficient and long-lasting which means huge savings on the energy bill as well as reduced maintenance costs. But what about the other benefits? Such as reduced crime rate, safer neighborhoods, and overall perceived improvement? These are all benefits that LED street lighting can offer compared to the orangey glow of the high pressure sodium (HPS) street lighting still illuminating most of our streets and neighborhoods.
Safer Streets
The biggest difference between LEDs and HPS lights (other than the energy savings, of course) is the overall appearance of the light. LEDs not only feature a crisp color similar to moonlight/natural light (anywhere from 4000K to 6000K), but also a great CRI of at least 70. This is hugely important because the CRI is what determines the visibility and ability to see things as intended. The CRI for HPS lights, in comparison, can be as low as 20. This makes visibility “muddier” and more difficult to discern detail and color. When visibility is decreased, so is safety which means an increase in crime. Visibility is an obviously important factor when it comes to lighting streets and neighborhoods at night. Take a look at this chart that compares basic statistics between LED street lighting and HPS.
Comparison Chart: LED VS HPS
| HPS | LED | |
|---|---|---|
| Optics | Non-uniform, optics degradation | Uniform, much less aging of the optics |
| CCT | 2000K | 4000-6000K |
| Life | 3,000hrs 30%-35% | 50,000hrs<5% |
| Power Factor | 0.85 | 0.95 |
| Turn on time | 15-20min | <0.1sec |
| Spectrum | Ultraviolet | No UV |
| CRI | 20-30 | >70 |
| Uniformity | Bad | Good |
| Environment | Hg | No Harm |
| Smart Control | No smart control | Smart control |
| Flickering | High pressure and high frequency op | Constant current, no flickering |
| Heat | High Heat, temp >100C | Less Heat, temp <60C |
| Voltage | 4000-7000V | 110-220V |
Case Study: Portland saving $100k per month
Portland recently converted 20,000 city street lights to LED in the largest efficiency the city has undergone. Savings from the program have now topped $100,000 per month and those monthly savings will continue to grow as more lights are converted. Read more here.
Case Study: Los Angeles reaches annual savings of $8.7 million
Los Angeles, CA began a huge installation of 140,000 LED street lamps in 2009. Since the conversion from HPS to LEDs, the city has recorded up to 63% energy savings and cost savings of $8.7 million this past year. The cost savings are the result of not only a savings in electricity cost, but a reduce in maintenance costs as well. As an article on Forbes reports, “In 2008, pre-LED roll-out, Los Angeles logged 70,000 street light repair and maintenance events; in FY 2012, maintenance and repair events fell to 46,300. LEDs are longer lived than the incumbent units they replace (10-15 years versus 4-6 years), which means that maintenance should steadily decline as LED units are fully deployed.”
Read the entire Forbes article on LA’s LED lighting project here.
The LUX Solution
LUX has a series of high-powered street and area lighting that can help you achieve great savings in your own city.
Our street/area lighting offers:
• Multiple color temperatures (3000K-5700K)
• CRI of 70 for great color rendering and visibility
• 50,000+ hour lifetime
• Superior reliability with 10 year limited warranty
• DesignLights Consortium certified
Contact us today for more information and sales quote!