Pollution Prevention Opportunity Assessment 29 May 2009 Retrofitting

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					                              Pollution Prevention Opportunity Assessment
                                                29 May 2009
                        Retrofitting Street and Parking Lot Lights with LED Lights

1. Contact Information: Robert Solyan, Pollution Prevention Program Manager, Aberdeen
Proving Ground (APG), MD 21005

2. Executive Summary: Aberdeen Proving Ground, in a recent study of 2,200 street and
parking lot lights on post, identified 1,500 high-pressure sodium (HPS) light bulbs that can be
replaced with light-emitting diode (LED) light bulbs that cause no harm to the environment,
provide sharper bright light, use substantially less energy, require little maintenance, and have
an extended life. APG will benefit by minimizing its environmental impact while saving money
and meeting mission needs.

Only fixtures with HPS light bulbs that could be removed and replaced with LED bulbs were
evaluated. Fixtures requiring alterations to the pole, receptacle, wiring, or power supply were
not considered; however, feasibility of those alterations will be evaluated in the near future.

Robert Solyan, who managed the study, gratefully acknowledges the participation of Ms.
Vickie Venzen, Ecco Verde Environmental Management & Training, Inc.


Assess the feasibility, cost, and long-term economic and environmental benefits of replacing
1,500 HPS street and parking lot light bulbs with LED light bulbs.*

4. Technical Evaluation

Conventional HPS bulbs have a lifespan of up to 24,000 hours, require annual maintenance,
and contain toxic materials such as mercury. By comparison, LED bulbs have a lifespan of up
to 50,000 hours, require no maintenance for up to five years, and contain no mercury.
Moreover, LED lighting produces more light per watt and consumes 50% to 80% less energy
than HPS lighting (Figure 1a).

E40, 150W HPS street lights can be replaced by 28W LED street lights using the 85-265V
power source, housing, and lens of the existing street light fixtures.

(APG street light bulbs vary from 70W to 400W. However, for the purpose of this initiative, all
comparisons are to E40, 150W HPS light bulbs, the most common bulbs used on APG for
street and parking lot lights)

 Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not
constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof

                          Figure 1a: LED versus HPS comparison.

5. Environmental Evaluation

This initiative could reduce the energy consumption, light pollution, and waste disposal costs
associated with HPS lighting.

Energy consumption
LEDs consume 50% to 80% less energy than conventional HPS street lights. In addition, LEDs
have a wide voltage range, allowing a much smaller wattage to be used to produce the same
amount of light as a higher wattage HPS bulb. (A 28W LED bulb can replace a 150W HPS
bulb and has an 85 to 265 voltage range.)

Light pollution
Traditional HPS street lights create light pollution through trespass (light directed beyond the
public right of way), over-illumination (excessive use of light), glare (excessive contrast
between bright and dark areas), and sky glow or sky shine (blocking of stars due to the release
of light into the night sky). LED street lights do not create light pollution and, as a result,
improve driving safety, reduce traffic accidents, and positively impact health and safety in

driving and walking areas (Figure 1b). In addition, LED street lights are an “environmentally
friendly” and “green" lighting source in that they contain no lead or mercury and produce no
heat and no ultraviolet or infrared light (Figure 1a).

                     Figure 1b: LED street light versus HPS street light.

                    Above: HPS street light on left, LED street light on right.
                     (Photo: LED Magazine, Penn Well Corp, Tech Group)

6. Economic Evaluation

Implementation of this initiative will reduce costs of energy; of handling, storage, and disposal
of hazardous articles that contain mercury; and of maintenance, labor, and operations.

7. Implementation Costs

Material purchase
One-time purchase of 1,500 E40, 28W LED street light bulbs: $360 per bulb x 1,500 bulbs =

Maintenance and labor
Approximately four weeks of labor to change out all existing HPS street light bulbs: $2,500 x 4
weeks = $10,000

HPS bulb disposal
$1.50 per bulb x 1,500 bulbs = $2,250

Total implementation cost: $552,250

8. Recurring Costs

Before implementation

Energy consumption and operation
APG used 268,608 MWh or units of electricity in 2008 at a cost of $25,250,000. (APG pays
approximately $0.10 per KWh.) Considering that on average 22% of electricity is used to
power lighting (based on information from the U.S. Department of Energy and the Maryland
Department of Energy) and one-third of that lighting is street and parking lot lighting, APG paid
approximately $1,852,000 for street and parking lot lighting in 2008.

Material purchases
Approximately $45 for each HPS bulb and annual replacement of each bulb: 1,500 bulbs x $45
= $67,500 annually

Maintenance, operation, and labor
Two workers, a truck, and equipment bi-weekly = $2,500
$2,500 x 26 weeks = $65,000 annually

Total current annual recurring cost: $1,984,500

After implementation

Energy consumption and operation
Approximately 60% savings on energy: $1,852,000 x 60% = $740,800 annually

Material purchases: $27,112

Maintenance and labor: $6,000

Total annual recurring cost after LED retrofit: $773,912

(Figures 2a and 2b)

      Figure 2a: Recurring cost and cost savings: Year 1.

Figure 2b: Recurring cost and cost savings: Year 2 and beyond.

9. Cost Savings

Savings result from the reduced energy consumption and operating costs as well as the
reduced maintenance and labor requirements.

Energy consumption and operation
First year after implementation and beyond: $1,111,200 annually

Material purchase
First year after implementation: $0 ($474,750 in new materials)
Second year and beyond: $40,388 annually

Maintenance and labor
First year after implementation: $55,000
Second year and beyond: $59,000 annually

Total cost savings
First year after implementation: $691,450
Second year and beyond: $1,210,588 annually

(Figures 2a and 2b)

10. Payback Period

Payback period is within the first year of implementation.

11. Implementation Status

This initiative is under consideration.