Street Lighting With LED’s

Prepared By:Wright Engineering Corporation165 E. Chilton DriveChandler, AZ 85225PH:480-497-5829

Presented By:R. Scott Wright, P.E., LC

Who am I?•Wright Engineering:

•26 years in outdoor and roadway lighting design

•R. Scott Wright , P.E.,LC•Lighting Certified through NCQLP, AZ IESNA Section Vice President, IES Streets & Area Lighting Committee, and AZ instructor for Fundamentals of Lighting “Outdoor Lighting” course. 17 years Outdoor Lighting Design Experience.

What are some good uses for LED Lighting Outdoors?

•Parking Lot Lighting•Accent & Decorative Lighting•Pathway Lighting•Street & Area Lighting

Important issues to consider when using LED Roadway Lighting

•Cost•Quality •Performance

•Public Opinion•Longevity•Maintenance

CostWhy LED Roadway Lighting?

•Energy Savings?•Historically in the attempt to reduce the power consumption in street and area

lighting, alternative light sources have been proposed to use less energy. It is

important to recognize that less energy may also translate to less light.

•Maintenance Savings?

•Federal or State Grants?

•Improved Illumination?

CostCompare your Alternatives

•Metal Halide (Decorative Areas)-(Good Color Rendering, Shorter Life)

•HPS-(Poor Color Rendering, Longer Life)

•LED-(Good Color Rendering, Longer Life)-(Don’t Want Too Blue)

CostCompare your Alternatives

Lamp Type

Lamp Wattage (watts)

Line Wattage (watts)

Lamp Life (hrs)

Lamp Life (years)

[maintenance cycle]

Fixture Cost

Maintenance Cost (per year)

Maintenance Cost (normalized to the LED fixture

life)Energy Cost (per year)

Energy Cost (normalized to the LED fixture life)

Total Cost of the Fixture (normailized to

the LED fixture life)100 Watt MH 100 122 12000 2.9 $175.00 $47.22 $675.00 $51.21 $732.00 $1,582.00100 Watt HPS 100 128 24000 5.7 $150.00 $23.61 $337.50 $53.73 $768.00 $1,255.5095 Watt LED 95 95 60000 14.3 $617.00 $9.44 $135.00 $39.88 $570.00 $1,322.00

LED Energy Savings in Comparison to:Usage 11.5 hrs/night 100 Watt MH 22.1%

4197.5Hrs/year 100 Watt HPS 25.8%

Return on Investment for LED Fixture:

Maintenance Cost $135.00 100 Watt MH 4.5 years

Electricity Cost $0.10per kW/hr 100 Watt HPS 6.0 years

-The above comparison shows typical lamp data for a 100 Watt MH lamp, a 100 Watt HPS lamp and an 95 Watt LED light source.-The LED fixture has a higher initial cost, however the savings come from the savings in maintenance and the savings in energy costs.-The LED fixture starts saving money over the metal halide fixture after 4.5 years.-The LED fixture starts saving money over the high pressure soduim fixture after 6.0 years.

QualityProper Heat Sink

In order to maintain proper LED junction temperature in Arizona ambient temperatures, a sufficient heat sink should be integrated to the luminaire

QualityIP Rated?(Ingress Protection)

Most Commonly IP 65 or IP 66 Rated

QualityAppearance of Quality•Will drivers be easily maintainable

•Will LED’s be easily replaceable

•Will cleaning or other maintenance be easily performed

QualityDOE SSL Checklist (unofficial):INPUT/OUTPUT:·  What are the delivered lumens?·  What is the real input power?·  Do you have LM-79 photometric reports and IES files from an independent testing lab? COLOR:·  What is the CRI at each color temperature?·  How do you ensure color consistency among fixtures built today or a year from now? Over the life of a product?·  Does the thermal management system keep the LED junction temperature below specified maximums in all applications?·  May I see at least two samples of the same CCT?·  Were your chromaticity measurements performed according to LM-79 by an independent lab?·  Is there a written binning policy?LIFE/WARRANTY:·  Is there a written end of life policy? How will spares be made available? How is failure defined?·  Do all system components from SSL manufacturer have a warranty and labor to fix/replace?·  How long is the warranty? What exactly is covered?·  Has LM-80 testing been performed by your LED or LED module manufacturer? What does it say about lumen maintenance?OTHER:·  Is the product ENERGY STAR qualified?·  Whose LEDs are being utilized?

QualityLM-79-08 & LM-80-08IESNA Publications

LM-79-08 Approved Method: Electrical and Photometric Measurements of Solid-StateLighting Products

LM-80-08 Approved Method: Measuring Lumen Maintenance of LED Light Sources

PerformanceExisting Light Levels?

Proposed Light Levels?

Does the Luminiare have an IES formatted photometric file (.ies)?

PerformanceMake a Comparison

How do we measure Efficiency?“Delivered Lumens”:

•In HPS Lumens are lost inside the Luminaire but, Reflectors are designed to optimize light output.

•Good Efficiency (~90% Efficient)

•In LED the lumens are delivered directly to the target with affixed lenses or aimed optics.

•Great Efficiency (~95%+ Efficient)HPS LED

Performance

Scenario:•Generic Type II lighting distribution with staggered lights on Collector Street.

HPS vs. LEDPerformance

PerformanceHow do we Save Energy in Street & Area Lighting?

•Remember the Primary Purpose of Outdoor Lighting:-Public Safety & Well Being

•If we are going to reduce the amount of energy consumed in lighting a space, we need to evaluate the effect on the required Minimum Light Levels.

Issues•Public Opinion

•Longevity

•Maintenance

Public Opinion

•Color Temperature of the LED Light Fixture = 2,800K - 6,500K

• Warmer Color vs. Efficiency

• Daylight = 5,500K• Clear Metal Halide = 4,500K• Halogen = 3,500K• HPS = 2,200K

Public Opinion

Public Opinion

• Most People Feel Comfortable in…• Most People Can See Easier in…

2700K->

<-5000K

Public Opinion

•Glare• Light Control Toward Neighbors• Offensive to Drivers• Shield the LED from Observer• LED Effectively Reduce Backlight,

but Struggle With Glare• Glare is Difficult to Measure

Longevity

Define L70 (What is it?)

The L70 Lifetime represents the number of hours where 70% or more of initial light output (lumens) is maintained.

Longevity

“When LEDs are installed in a luminaire or system, there are many additional factors that can affect the rate of lumen depreciation or the likelihood of catastrophic failure.”

• Temperature Extremes• Humidity• Moisture Incursion• Voltage or Current Fluctuations• Driver failure

“In Summary, LED Luminaire life is not identical to estimated LED life.”

(2009 Study by Pacific Northwest National Laboratory - www.ssl.energy.gov)

Longevity

•Lifespan?• Example: 75,000 Hours Published

LS = 75K hours/11.5 hours per night / 365 days per year

LS = 17.87 Years

Longevity

• Junction Temperature Control• Driver Lifespan• Photo Cell Lifespan• Paint Finish• Warranty• Cleaning / Maintenance Expected?

Maintenance

•Easy of maintenance • Toolless Access• Quick Disconnects

•Cleaning• Lens or Other Optics• Heat Sink

Maintenance

•Keeping Heat Sink Fins Clean•Designed to Keep Heat Sink Operational•Dirt•Dust•Leaves•Debris•Bird Waste•Rain or Wash Down?

Maintenance

• Catastrophic vs. L70 “End of Life”

• Catastrophic = Easily Determined

• Catastrophic = Warranty Recovery

Maintenance

•How to Determine L70 “End of Life”?• Keep Records of Installation Dates• Take Initial Lumen Readings

• Actual vs. Theoretical• Take Lumen Readings at Intervals

• 5, 10, 15 Years?• Sample Control Group in a Parking Lot or

Roadway• Liability if Less Than L70?• Maintenance Schedule for Replacement

Street Lighting With LED’s•Cost

•Return On Investment•Quality

•Heat Sink•IP Rating•DOE Quality Questions

•Performance•Meets Standards?

Street Lighting With LED’s

•Public Opinion•Color & Glare

•Longevity•L70 & Entire Luminaire System

•Maintenance•Maintenance Free?•Periodic Photometric Testing?

Questions?

Prepared By:Wright Engineering Corporation

165 E. Chilton DriveChandler, AZ 85225PH:480-497-5829

Presented By:R. Scott Wright, P.E., LC

L70 Graph

L70 Lumen Depreciation Characteristics Summary Graph from the Pacific Northwest National Laboratory test published October 2009 – www.ssl.energy.gov

•Induction is a great light source for certain applications, but general street lighting is not one of them.  Because of the large Lamp size of both the Philips QL and Sylvania Icetron lamps, it is extremely difficult to achieve the light distribution and uniformity required in street lighting.  •Induction is essentially a non-progressing technology.  Philips has offered the same 55, 85 and 165-watt QL system for almost 20 years and is not expanding the line.  All of their R&D and acquisition dollars are going to Lumileds (LED).  Likewise, Sylvania has done nothing significant to advance the Icetron technology.•QL lamps are not 100,000 hr lamps.  That’s the rated life, which is the ½ life, meaning that at the 100,000-hr point, the user can expect only ½ of the lamps to still be functioning.  Some will fail much earlier, but by 100,000 hrs, you will have a 50% failure rate.•Comparing Induction lamps to LED using the L70 measurement of useful life, LED systems typically exceed 70,000 hrs to L70 with no failures.  Per Philips, the QL systems reaches L70 at 60,000 hrs with a 10% failure rate.•From an efficacy standpoint, Induction can produce up to 70-90 lumens per watt, whereas commercially available LEDs already exceed 130 lumens per watt.  Per the above point, Induction is not going to get any better, whereas LED efficacy continues to steadily improve.  Cree already has diodes in the lab that exceed 200 lumens per watt, which you can expect to be commercially available within 2-3 years.•In terms of lumen depreciation, Induction loses almost 10% of its output in the first 5,000 hours.•Due to its reduced lumen output, promoters of Induction or even “Bad” LED technology have pushed that because it is a “White” light source, less lighting can be used than that where HPS is used. This research has been actively reviewed and is not, as of yet, been adopted by the IES and may not be in the near future for Roadway Lighting.

•Induction vs LED vs HPS vs Metal Halide (discuss efficacy, life, etc)•Philips HPS Non-cycling lamp now offers 30,000 hours at a 65% survival rate with 85% lumen maintenance (at 5,000 hours LM is at 96%, 20k @ 87%)•Philips QL Induction at 30,000 hours gives a 97% survival rate with 81% lumen maintenance (at 5,000 hours LM is at 87%, 20k @ 83%)•HPS has superior characteristics in initial lumens and maintained lumens•HPS efficacy for standard 100W – 250W ranges from 70lm/watt to 90lm/watt•Induction efficacy ranges from 65lm/watt – 75lm/watt•Keep in mind that these efficacies do not take luminaire efficiency into account•Induction does not save energy over traditional HPS •Spacing and light levels for municipal street lighting has always been based on HPS light source – installing induction with same spacing criteria gives lower light levels - what is the liability of doing this?•Induction is a fluorescent electrodeless source (no electrode gives long life)•Conventional fluorescent current is supplied to gas discharge through glowing electrodes – Induction supplies current to gas discharge through HF emag field•Lamp contains Amalgam (Mercury Metal Mixture)•Who is making the induction generators and lamps – Chinese components don’t last and the companies typically go out of business and unable to honor warranties or provide replacement parts•High Frequency generator & lamp heat dissipation