City of Houston LED Street Light Conversion Project
May 8, 2015

CenterPoint Energy LED Street Light Replacement
The purpose of this presentation is to:
• Introduce LED street lighting technology
• Highlight CNP’s LED pilot program and evaluation process
• Provide information on the conversion project with City of Houston
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Street Lighting Background
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 High Pressure Sodium
 Amber/Orange in Color
 Standard Installation
 Economical – 8 year life
 Metal Halide
 White/Blue in Color
 Not Economical – 2-3 year life
 More Expensive
 Mercury Vapor
 White/Blue in Color
 Restricted Availability
 1,000 left in system
 LED – Light Emitting Diode
 White/Blue in Color
 Highly Efficient – 8-10 Years

The U.S Department of Energy estimates that widespread adoption of LED lighting by 2025 will:
• Reduce electricity demands from lighting by 62 percent.
• Eliminate 258 million metric tons of carbon emissions.
• Reduce the amount of materials being put into landfills.
• Avoid the building of 133 new power plants.
• Save the US over $280 billion.
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Typical Lighting-class LED Package
Lens, RI ~1.4
Substrate
Wire Bond
Phosphor
LED chip
• Protection for the LED chip from the outside environment
• Conductive path to carry generated heat away from the LED chip
• Lens & encapsulant systems should not discolor under
UV and exposure to high amounts of luminous flux
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HID lamps:
Technological Differences:
– Directionality of generated light
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Omni-directional (HID)
• Directional (LED)
(light)
(heat)
LEDs:
(heat)
– Means of evacuating generated heat
•
Convection (HID)
•
Conduction (LED)
– Light Source
•
Single (HID)
•
Multiple (LED)
(light) (light)
90 °-140° viewing angle
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HID Light Pattern vs. LED Light Pattern - 150W HPS
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HID Light Pattern vs. LED Light Pattern - 150W HPS
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HID Light Pattern vs. LED Light Pattern
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HID Light Pattern vs. LED Light Pattern
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Traditional Street Lights vs. LED Luminaires
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Traditional Street Lights vs. LED Luminaires
Operate – A Culture of Safety – High Quality White Light
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Traditional Street Lights vs. LED Luminaires
Serve – Customer Focus – Societal Benefits such as Dark Sky Initiative
Los Angeles Skyline – 2008
Los Angeles Skyline – 2012
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CenterPoint Energy has been conducting pilot testing of the technology for the previous six years
ADVANTAGES
• Energy efficient: 80% of the electricity used by an LED is converted to light, compared to just
10% for incandescent bulbs.
• Long and predictable life: LEDs last up to 100,000 hours or more; substantially longer than High
Pressure Sodium and Metal Halide lamps
• Excellent CRI (color rendering index): LEDs can produce a high quality of white light that allows the eye to detect colors more effectively.
• Environmentally friendly: LEDs emit very little infrared radiation and contain no mercury.
• Directional lighting: LEDs focus light in a particular direction, making them useful for spotlight and other applications.
• Quick turn on and off: LEDs come on with full brightness instantly. Unlike mercury vapor, metal halide and sodium vapor lamps (commonly used in street lighting), LEDs do not have a problem restarting immediately (hot ignition) following a brief power failure or inadvertent turn off.
LED luminaires may provide up to approximately 60% kWh energy savings for the end-use customer
DISADVANTAGES
• Cost: LEDs are currently more expensive than other conventional HID sources.
• Heat: LEDs are very heat sensitive. Correct dissipation of heat is necessary to light output and lifespan of the fixture.
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CenterPoint Energy LED Pilot Study
• In May of 2009, CenterPoint Energy was approached by our largest street light user, the city of Houston (approximately 175,000 lights), about exploring LED lighting and its benefits and possibilities.
• These lights have been installed at no charge to our customer base in a local subdivision that would promote and allow feedback from the community.
Initial Participation Criteria
• Provide 3 LED test fixtures to replace a 100W high pressure sodium fixture
Meet full cut-off requirements and
Type II Distribution
• The test location is an existing subdivision in Southeast Houston with no competing tree canopies and the luminaire mounting heights are at 30 feet.
The pavement width is 28 and all poles are staggered approximately 180’ apart.
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CenterPoint Energy Sample Pilot Map
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Field Measurements
Street number:
Street name:
Company:
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Linden Gate Dr.
Brand X
15 ft behind pole
0.478
Pole / number Street readings
484427 O 0.499 0.807 0.694 0.671
0.408 0.586 0.626 0.421
0.321 0.340 0.371 0.344
Pole / number 15 ft behind pole
0.782 0.686 0.812 0.472O 484429
0.427 0.382 0.441 0.323
0.340 0.373 0.318 0.286
484428 O 0.512 0.760 0.630 0.741
0.459
0.496
Lighting
Calculations
Total FC =
Average FC =
Minimum FC =
Uniformity =
14.373
0.513321429
0.286
1.79483017
(28 readings on pavement between 3 fixtures)
(Average/minimum)
Notes
1. All measurements in foot candles
2. Measurements taken June 14, 2010 after 9:00 pm CDT. Lunar phase: new moon (beginning June 12).
3. All light locations are approximately 180' apart and the width of the pavement is 28'.
4. Readings are taken at 60' lengths along the street and 9' widths starting under the pole.
5. Temperature readings taken on September 13, 2010 at approximately 9:30pm.
Readings were taken 4' off curb and 32'' above grade:
Light #487731 - 5190K and #484432 - 4650K # 484429 - 6340K and Light # 484428 - 6369K.
0.499
0.408
0.321
0.782
0.427
0.340
0.512
0.807
0.586
0.340
0.686
0.382
0.373
0.760
0.694
0.626
0.371
0.812
0.441
0.318
0.630
Note: Darkest area represents strongest concentration of light.
0.671
0.421
0.344
0.472
0.323
0.286
0.741
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Street Light Luminaire Replacement in the City of Houston
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The COH LED Conversion Project includes replacing approximately 175,000 mercury vapor, high pressure sodium, and metal halide luminaires with LED alternatives
• Removal of existing HID luminaire, lamp and Photoelectric Relay (PER)
• Installation of equivalent LED luminaire
• Installation of “hardened” Photoelectric Relay (PER)
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Equivalent LED Luminaires
LED Luminaire Percent of CNP Lamps Alternative For
45 Watt ~75%
• 100W MV*
• 100W HPS*
• 70W HPS
• 100W MH*
95 Watt
115 Watt
180 Watt
~10%
~14%
~< 1%
• 175W MV
• 150W HPS
• 175W MH
• 250W HPS
• 250W MH
• 400W MV
• 400W MH
* MV = Mercury Vapor, HPS = High Pressure Sodium, MH = Metal Halide
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CNP Approved LED Street Lights
45W, 4800 lumen LED Luminaire
Allowable Range:
45 – 56W
4400 – 5400 lumens
Vendor A
95W, 7900 lumen LED Luminaire
Allowable Range:
85 – 105W
7110 – 8690 lumens
Vendor B
115W, 10850 lumen LED Luminaire
Allowable Range:
102 – 125W
9850 – 11850 lumens
Vendor C
**All approved fixtures are required to have a minimum 10 year warranty
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Street Light Luminaire Replacement in the City of Houston
• CenterPoint Energy is replacing approximately 175,000 mercury vapor, high pressure sodium, and metal halide luminaires with LED alternatives
• The anticipated time frame for completion of the project is within five years
Year 1 Year 2 Year 3 Year 4 Year 5
20% 25% 25% 15% 15%
*Time schedule is contingent upon workforce availability and vendor production constraints
• The anticipated number of LED conversions per year
Year 1 Year 2 Year 3 Year 4
35,000 43,750 43,750 26,250
Year 5
26,250
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5 Year Deployment Map
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City of Houston Conversion Project Timeline
August 2014 – New LED Street Light tariff rate submitted for PUCT approval
November 2014 – PUCT approves new LED Street Light tariff
December 30, 2014 – New LED Street Light rates are effective
January 1, 2015 – Initiated new LED ESI# creation
January 5, 2015 - Began deployment of 45W cobra LED street lights
February 11, 2015 – CNP Material Standards Dept. approves 95W and 115W manufacturers
March 16, 2015 – Street Light Outage maintenance crews began converting lights on regular maintenance
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 6 deployment crews
 Deployment crew consists of one utility head lineman
 On average each crew completes 15 – 20 conversions/day
 Issued a total of 12,636 street lights for conversion to date o 10,300 – 45W LED fixtures o 1,117 – 95W fixtures o 1,219 – 115W fixtures
 Converted 6,490 street lights to 45W LED
 24 Street Light Outage maintenance crews
 Converted approximately 900 street lights as of April 15, 2015

Street Light Luminaire Replacement in the City of Houston
• CenterPoint will continue to work toward identifying LED replacement luminaires for the approximate 8,000 City of Houston street lights not covered by the new LED
Tariff rates
• Estimated kWh savings to the City of Houston: Over 70 million kWh annually
• City of Houston projects $28 million in savings over 10 years
• No upfront cost to the City of Houston
• Initially customers will continue to pay the same monthly CNP tariff rate as current technology; however LED rates will change in the future.
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Challenges
Equipment Failures
 8 Luminaires o 5 Receptacle failures o 3 Driver failures
 3 Photocells
All approved street lights and photo controls have a minimum 10 year warranty
Coordinating deployment with Public Works Capital Improvement Projects
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LED Conversion Program Expansion
Currently the 100W, 150W, 250W, & 400W high pressure sodium are the CNP standard street lights
Municipalities and Home Owner Associations requesting LED street lights will be required to enter into an agreement. Some of the terms & conditions included are:
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Deployment Schedule for Conversions
The deployment schedule will be based on the number of lights and current workload
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All new street light installations, including the 6% allotment, will be LED technology
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Agreement to the recently accepted LED tariff rates, and the potential of increased
LED tariff rates in the future
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Financial Impact of LED Street Light Conversion
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LED fixtures average 1 ½ to 3 times the cost of standard HPS fixtures
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LED luminaire costs have decreased significantly over time and are expected to continue to decline
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Additional capital labor required to replace existing lights
 Undepreciated HPS fixtures remain in the streetlight asset base
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Energy consumption will decrease by as much as 50% (Retail Provider)
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Monthly fixture charge paid to CNP will likely increase substantially
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CNP plans to recover LED conversion costs through DCRF annual filing
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Increased life of the LED luminaire, coupled with the “hardened” PER is expected to reduce street light outages
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Summary
• Conduct a comprehensive evaluation of each LED luminaire
Evaluate photometric files and perform field evaluations
• Growing demand for municipalities to decrease their carbon footprint
Great opportunity to partner with customers on a green initiatives
• LED street lighting is an emerging technology
The many benefits of LED street lighting should be weighed against the cost of a conversion and potential maintenance savings
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